Discussion Paper No. 494

VOLUNTARY PARTICIPATION GAME EXPERIMENTS
WITH A NON-EXCLUDABLE PUBLIC GOOD:
IS SPITEFULNESSA SOURCE OF COOPERATION?

Tatsuyoshi Saijo
Takehiko Yamato
Konomu Yokotani
andTimothy N. Cason

January 2000

The Institute of Social and Economic Research
Osaka University
6-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan

Voluntary Participation Game Experiments with a Non-Excludable Public Good:Is Spitefulness a Source of Cooperation?1

by

Tatsuyoshi Saijo*
Takehiko Yamato**
Konomu Yokotani***andTimothy N. Cason****May, 1997; Revised April, 1999

1 We thank Takenori Inoki, Hajime Miyazaki, Toru Mori, Mancur Olson, Mitsuo Suzuki, and participantsat the Fall 1996 Economic Science Association conference for their helpful comments and discussions.
This research was partially supported by the Zengin Foundation for the Studies on Economics andFinance, Grant in Aid for Scientific Research 08453001 of the Ministry of Education, Science and Culture
in Japan, and the Tokyo Center for Economic Research Grant.
* Institute of Social and Economic Research, Osaka University, Ibaraki, Osaka 567-0047, Japan, andCREST, Japan Science and Technology Corporation, 3-12-40 Hiroo, Shibuya, Tokyo 150-0012, Japan.
E-mail address: saijo@iser.osaka-u.ac.jp** Faculty of Economics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan. E-mailaddress: yamato-takehiko@c.metro-u.ac.jp*** Research and Survey Department, The Government Housing Loan Corporation, 1-4-10 Koraku,
Bunkyo, Tokyo 112-8570, Japan. E-mail address: QZT03105@niftyserve.or.jp****Department of Economics, Krannert School of Management, Purdue University, West Lafayette, IN
47907-1310, USA. E-mail address: cason@mgmt.purdue.edu

Abstract

Economic theory predicts that it is impossible to have cooperation in finitely
repeated games such as a prisoners' dilemma game without communication. Yet
experimental results follow a contradicting pattern: for example, cooperation is generally
observed in public-goods experiments, at least in early rounds. This cooperation is often
interpreted as kindness or fairness. In an experiment on a voluntary participation gamewith a non-excludable public good that is a version of a Hawk-Dove game, we observedthat evolutionary stable strategies did not appear, but cooperation emerged through atransmutation from the Hawk-Dove game to a game where a dominant strategy outcome
is Pareto efficient. We found that this transmutation is not due to kindness, but tospitefulness among subjects.

Correspondent:
Tatsuyoshi Saijo
Institute of Social and Economic Research
Osaka University
Ibaraki, Osaka 567-0047
Japan
Phone 81-6 (country & area codes)
879-8582 (office)/878-2766 (fax)E-mail: saijo@iser.osaka-u.ac.jp

1. Introduction
Economic theory usually predicts that it is impossible to have cooperation in
finitely repeated games such as a prisoners' dilemma game without communication.2 Yetexperimental results follow a contradicting pattern: some cooperation is generally
observed in public-goods experiments, for example, particularly in early rounds (seeLedyard, 1995). This cooperation is often interpreted as kindness or fairness. Andreoni(1995) confirmed that it comes from kindness or altruism of subjects. Most previous
public goods experiments employ the voluntary contribution mechanism, in which eachsubject contributes some money to provide a public good so as to maximize her payoff orutility. A well-established theoretical result is that the Nash equilibrium outcomes of thevoluntary contribution mechanism are not Pareto efficient.
Another line of experimental research in public goods is to investigate
performance of mechanisms achieving Pareto efficient outcomes such as the GrovesLedyard mechanism (1977). As Chen and Plott (1993) showed, the Groves-Ledyard
mechanism works very well under some suitable punishment parameters.
Recently, Saijo and Yamato (1997, 1999) shed a new light on the meaning ofvoluntary participation in public goods provision mechanisms. Agents may have a choice
not to participate in the mechanism proposed and hence some of them can free-ride on thebenefit from a public good provided by others. In other words, most of the mechanisms
designed so far -- including the voluntary contribution mechanism -- implicitly ignore
non-excludability, which is one of the important features of a public good. Instead,designers assume that all agents must participate in the mechanism. Saijo and Yamato

2

Many theorists have been trying to explain cooperation with finitely repeated games. A basic idea is tointroduce some irrationality with or without complete information. See Radner (1980), Kreps, Milgrom andWilson (1982), Benoit and Krishna (1985), and Conlon (1996).

1

(1997) proved an impossibility theorem demonstrating that no mechanism satisfying
voluntary participation exists in very reasonable environments.3
This participation problem is important in many practical circumstances, such as
for international treaties. For example, it took 24 years to reach agreement on thedisposition of chemical weapons in the chemical weapons treaty, and the number ofsignatories was more than 160 by the end of 1995. The treaty is a mechanism creating apublic good, i.e., a greater likelihood of world peace. The treaty requires that at least 65
signatories must ratify it in order to make it effective. In October 1996, Hungary was the65th country to ratify it, and the treaty was effective after a half year. However, China
and Russia have the most chemical weapons have not ratified this treaty. This could limit
the treaty's effectiveness. Another example is the League of Nations. Following WorldWar I President Woodrow Wilson strongly supported the League, but the U.S. Congress
never ratified the Treaty of Versailles. Another more contemporary example is the Kyoto
Protocol on climate change in 1997 to reduce greenhouse gas emissions. A large numberof countries appear unwilling to participate in the provision of this obviously nonexcludable public good.
Voluntary public goods provision by individuals -- such as for public broadcasting-- also faces this participation problem. For example, part of public broadcasting in Japanis supported by the public broadcasting fee. Every family must pay the fee by law, butmany choose not to since enforcement is practically non-existent. A natural question to
ask is what would happen if we allow voluntary participation in the voluntary
contribution mechanism.
We conducted an experiment to study the voluntary contribution mechanism withvoluntary participation in a two-stage game. In the first stage, two subjects choose3

See also Dixit and Olson (1997) for the voluntary participation problem in the context of the Coase theorem.

2

simultaneously whether or not they participate in the voluntary contribution mechanism.
In the second stage, knowing the other subject's participation decision, subjects who
selected participation in the first stage choose contributions to the public good. Subjects
receive payoffs based on a Cobb-Douglas transformation of their consumption of the
public good and their private good. The normal form game representation of the firststage participation decision is a Hawk-Dove game rather than the Prisoners’ Dilemma
game that represents the typical voluntary contributions mechanism with mandatory
participation. As usual, this Hawk-Dove game has two pure strategy Nash equilibria andone mixed strategy Nash equilibrium which is the unique evolutionarily stable strategy(ESS) equilibrium.
We conducted two treatments. Both subjects were required to participate in thevoluntary contribution mechanism in the control Treatment A. Each subject could choose
her participation decision before her contribution decision in Treatment B. Thus,
Treatment A only included the second stage, while Treatment B included both stages.
Each treatment had twenty subjects and each subject was randomly paired with eachother subject one at a time – a so-called “strangers” design. The same game was repeated
19 rounds, 4 for practice and 15 for monetary reward, so as not to pair the same two
subjects more than once.
In Treatment A, subjects on average contributed (or "invested") close to the Nashequilibrium level, although some subjects exhibited spiteful behavior. A spiteful subject
explicitly stated on her record sheet that she chose an investment number less than the
Nash equilibrium investment so as to reduce her opponent's payoff more than her own
payoff reduction.4

4 Saijo and Nakamura (1995) observed spiteful behavior in a traditional voluntary contribution mechanism

experiment. See also Ito, Saijo, and Une (1995). Spiteful behavior is also observed in biology. Iwasa,

3

In Treatment B, the participation rate rose as rounds advanced, and the average
investment in the final rounds in Treatment B was very close to that in Treatment A.
Consequently, in the final two-thirds of Treatment B, subjects' participation rate nearly
always exceeded the ESS participation rate. A typical subject behaved as follows: at the
beginning she did not participate in the mechanism, expecting high payoff with freeriding. However, her opponent who decided to participate in the mechanism did notinvest the number that maximized his own payoff. Rather, he invested a smaller amountso as to reduce his opponent's payoff more than his own payoff reduction. The nonparticipating subject thus learned that non-participation was not beneficial to her andhence she began regularly participating in the mechanism. That is, it seemed that thesource of cooperation was not altruism or kindness but was a payoff-maximizing responseto the spiteful behavior of other subjects. What we call cooperation here means that bothsubjects participate in the mechanism.
The remainder of the paper is organized as follows. In Section 2 we explain thevoluntary contribution mechanisms with and without voluntary participation. Section 3
describes the experimental design. We present the results on the experiment of thevoluntary contribution mechanism without voluntary participation in Section 4 and thoseon the experiment of the voluntary contribution mechanism with voluntary participationin Section 5. Section 6 concludes.

2. The Voluntary Contribution Mechanism
We employ the voluntary contribution mechanism with or without voluntary
participation as our model.

Nakamaru, and Levin (1998) set up a model explaining spiteful behavior of colicin-producing bacteria against
colicin-sensitive bacteria.

4There are two subjects, a and b, and subject i (=a,b) has wi units of initialendowment of a private good. Each subject faces a decision of splitting wi between her
own consumption of the private good ( x i ) and investment ( y i ). From the investment,each subject receives y = y a + y b + wy , where wy is the initial level of the pubic good.
That is, the level of the public good is the sum of the investments of two subjects and theinitial level of the public good. Therefore, each subject's decision problem ismax u i ( x i , y ) subject to x i + y i = wi ,where ui (x i , y ) is subject i's payoff function. We use a Cobb-Douglas type payoff function
to transform contributions and the private good into subject payoffs, and all subjects havethe same payoff function. That is, ui ( xi , y ) = xiα y1−α , where α ∈( 0 ,1). Using a monotonic
transformation, we specify the payoff function as follows:(1)

ui (x i , y ) ={ x iα y 1 −α }β+ 500 .
50

In our experiment we set ( wa , wb , wy ) = (24 ,24 ,3) , α = 0 .47 , and β = 4 .45 . With theseparameters the Nash equilibrium investment pair of the voluntary contribution
mechanism is ( y a , yb ) = ( 7 .69 , 7 .69 ) and the payoff is ui ( xi , y ) = 7089 , wherex i = 24 − 7 .69 = 16.31 and y = y a + y b + w y = 18.38 . The Pareto efficient level of the public

good is determined uniquely by the Samuelson condition and the feasibility condition. Its
symmetric contribution level is 12.02. Therefore, the Pareto efficient level of the public
good is 27.04=12.02+12.02+3. Clearly, the level of the public good with the voluntary
contribution mechanism is less than the Pareto efficient level of the public good.

5

So far we have assumed implicitly that subjects must participate in the voluntary
contribution mechanism. Saijo and Yamato (1997) found that there is a wide class of
mechanisms with public goods where subjects have incentives not to participate. The
voluntary contribution mechanism is one of them. That is, the voluntary contribution
mechanism is not voluntary from the viewpoint of participation incentives.
Consider now a two-stage game (see Figure 1). In the first stage, each subject
simultaneously decides whether or not she should participate in the voluntary
contribution mechanism without knowing the other subject's decision. In the second
stage, each subject decides how many units of her initial endowment she should invest
after knowing the other subject's participation decision.
-------------------------------Figure 1 is around here-------------------------------Notice that non-participation is different from zero investment with participation.
Once subject a decides to participate in the mechanism, subject b must take account of thisfact when she chooses her investment number without knowing subject a's investment
number. On the other hand, if subject a chooses non-participation, then subject b knowsthat subject a invests nothing.
In our experiment, subjects choose integer investment numbers only. If bothsubjects decide to participate in the mechanism, then the Nash equilibrium of thatsubgame is for each subject to contribute 8 and obtain a payoff of 7345. No other Nashequilibria sneak into our model due to the discrete strategy choice set. If one subject
participates in the mechanism and the other does not, then the participant maximizes her
payoff at y i = 11 and obtains a payoff of 2658, and the non-participant clearly invests
nothing and obtains a payoff of 8278. If both choose not to participate in the mechanism,

6both subjects end up with a payoff of 706. These payoffs are summarized in the normal
form game payoff table shown in Table 1.
-------------------------------Table 1 is around here-------------------------------The game in Table 1 is a well-known Hawk-Dove game. Although the usual
simplification of the public good problem is a Prisoners' Dilemma game, we find that theproper simplification is a Hawk-Dove game when we allow participation in themechanism as a choice variable. There are two pure strategy Nash equilibria: either one ofsubjects participates in the mechanism. One more Nash equilibrium is a mixed strategy
equilibrium: each subject i chooses 0.68 as her participation probability p i . Among thesethree equilibria, the mixed strategy equilibrium is a unique ESS equilibrium.5

3. Experimental Design
Our experiment consisted of three treatments, A, B, and B’. Treatment A
corresponded to the voluntary contribution mechanism without voluntary participation
and Treatments B and B’ corresponded to the voluntary contribution mechanism withvoluntary participation. We will explain the difference between Treatment B and
Treatment B’ below.
We conducted one session in Treatment A and one session in Treatment B at the
University of Tsukuba during December of 1995, and one session in Treatment B and one
session in Treatment B’ at the Tokyo Metropolitan University during December of 1997.
We recruited twenty students for each session by campus-wide advertisement. Thesestudents were told that there would be an opportunity to earn money in a research

5 See Maynard Smith (1982).

7

experiment. None of them had prior experience in a public good provision experiment.
No subject attended in more than one session. The Treatment A session required
approximately 90 minutes and the Treatment B and B’ sessions required approximately
two hours to complete. The mean payoff per subject was $26.31 ($1=100 yen). The
maximum payoff among the eighty subjects was $36.25, and the minimum payoff was$17.28.
Let us describe Treatment A first. Twenty subjects seated at desks in a relatively
large room had identification numbers between one to twenty randomly. These
identification numbers were not publicly displayed, however, so subjects could not
determine who had which number. We made ten pairs out of twenty subjects. In eachround, ten pairs played the game without the participation decision as described in theprevious section. The pairings were determined in advance by experimenters so as not topair the same two subjects more than once. The first four rounds were for practice and theremaining fifteen determined the subjects' monetary payoffs. Each subject received anexperimental procedure sheet, a record sheet, payoff tables, 15 investment sheets, and 4
practice investment sheets.6 Instructions were given by tape recorder to minimize theinteraction between subjects and experimenters. Each subject determined her investment
from an integer number between 0 and 24 by using payoff tables and then marked anumber on an investment sheet. Experimenters collected these investment sheets andthen redistributed them to the paired subjects. During the redistribution, subjects wereasked to fill out the reasons why they chose these numbers. After the redistribution,subjects calculated their payoffs from the payoff tables. Then the next round started.

6 The use of practice periods permits subjects to send signals costlessly prior to the paid rounds.

However,subjects interacted with each other in only one period and there was no public information after the
instructions were completed and data collection began. Therefore, the impact of these signals is somewhat
limited. Nevertheless, see footnote 14 for some minor evidence of spillover from the practice periods.

8Treatment B had one additional step. Before choosing investment numbers,
subjects decided whether or not they would participate in the voluntary contribution
mechanism. These decisions were collected by experimenters and then redistributed totheir paired subjects. After this procedure, subjects who decided to participate in themechanism chose their investment numbers.
Treatment B’ is exactly the same as Treatment B except what term was used todescribe the person that each subject is matched with at each period. The term "youropponent" was employed in the instructions, record sheets and payoff tables for bothTreatment A and Treatment B. The phrase "the person you are paired with" replaced"your opponent" in all materials of Treatment B’. One might say that the term “opponent”
forces subjects to think in relative terms. However, there was no essential difference
between the results for Treatment B and those for Treatment B’, as we document below.
Every subject had the same payoff function and every subject knew this fact. We
distributed three kinds of payoff tables to avoid any possible misunderstanding. The
payoff tables used in Treatments A and B are Tables 2, 3, and 4. Table 2 is a detailed
payoff table: the rows are for the subject's own investment numbers and the columns arefor the other subject's investment numbers. Table 3 is a rough payoff table and Table 4 has
an iso-payoff map. The payoff tables distributed in Treatment B’ are the same as Tables 2,
3, and 4 except that the term "your opponent" is replaced by the term "the person you arepaired with".
We allowed subjects three minutes to examine the three payoff tables before thepractice rounds and ten minutes to examine the three new payoff tables before the realrounds. The tables used for practice and real rounds were different.
--------------------------------------------Tables 2, 3 and 4 are around here---------------------------------------------

9

We declared that the experiment would be stopped if communication among the
subjects was observed. This never happened.

4. Experimental Results for Treatment A
Treatment A was a control treatment intended to permit a comparison between
mandatory participation and voluntary participation.
The Nash equilibrium investment pair was (8, 8) from Table 2, and no other Nashequilibrium exists. Since each round had 10 pairs and 15 rounds were conducted, we have
150 pairs of data. The order of investment numbers does not matter, so we rearranged
each pair (x,y) with x ≥ y . Figure 2 shows the frequency distribution of investment data.
The maximum frequency pair was (8, 8) with 36 pairs, the second was (8, 7) with 35 pairs,
the third was (8,6) with 14 pairs, and the fourth was (7, 7) with 11 pairs. The average
investment across all subjects was 7.24.
-------------------------------Figure 2 is around here-------------------------------Figure 3 shows the average investment pattern from round 1 to 15. The average
investment was less than the Nash equilibrium level of investment (8) in all but one round.
In order to understand why this happened, we checked the record sheets andquestionnaire sheets of subjects. The record sheet was not only for keeping theinvestment record but also for specifying the reasons why a subject chose her investment
numbers. We found four subjects who explicitly stated the following reasoning: they
estimated that their opponent would chose 8, and then they chose 6 or 7 explicitly because
this would make their opponent's payoff much lower than their own payoff. For example,

10

consider the case that subject a chooses 7 and subject b chooses 8. Then subject a obtains
7340, and subject b obtains 6526. At the Nash equilibrium (8, 8), both subjects obtain 7345.
From the viewpoint of subject a, the reduction of 5 units of payoff is minor, but subject a
can make the reduction of subject b's payoff (819) much greater than his own reduction.7, 8
We label these subjects as spiteful subjects, and Figure 3 also presents mean investments
after excluding those subjects.
-------------------------------Figure 3 is around here-------------------------------We tested the hypothesis that mean investment equals the Nash equilibrium
investment (8) first by pooling investments across rounds. Because each subject made 15
investment choices the data are clearly not independent. Therefore, we accounted for thepanel nature of the data using a random effects error specification vit = ei + ε it, where ei is asubject-specific error term and ε it is an iid error. The pooled data strongly reject the Nashequilibrium (t=3.28), and also reject the Nash equilibrium when spiteful subjects are
excluded (t=4.45) and when spiteful subjects and their opponents' data are excluded(t=3.75). We then focused on round by round tests of the Nash equilibrium. Without
excluding any data, a nonparametric Wilcoxon signed rank test rejects the Nashequilibrium hypothesis in ten out of fifteen rounds at the five percent significance level.
Excluding spiteful subjects' data, this test rejects the Nash equilibrium hypothesis in fiveout of fifteen rounds. Finally, excluding spiteful subjects' and their opponents' data, thistest rejects the Nash equilibrium hypothesis in four out of fifteen rounds. Nevertheless,
7 Akerlof and Yellen (1985a, 1985b) observed similar phenomena in Keynesian business cycles and industrialorganization theory. A small amount of nonmaximizing behavior may cause some amount of changes atequilibrium that is larger in its magnitude than the losses due to nonmaximizing agents.
8Note that this spiteful (non-maximizing) behavior would not be observed in a usual two-by-two game. In
our experimental setting, subjects can choose a slight deviation from an optimal investment strategy. That is,
the two-by-two game approach is not rich enough to capture economic implications in public goods
environments.

11the fact that many subjects chose the Nash equilibrium investment indicates that at least
economically the Nash equilibrium has attracting power for the data.9

These Treatment A results lead to the following observation.
Observation 1:
The mean investment across all rounds is significantly less than the Nash equilibrium
investment, regardless of whether spiteful subjects' data are excluded. Overall, mean investments
were approximately ten percent below the Nash equilibrium.

5. Experimental Results for Treatments B and B’
The session in Treatment B conducted at the University of Tsukuba, the session in
Treatment B at the Tokyo Metropolitan University, and the session in Treatment B’ at theTokyo Metropolitan University are called the Tsukuba B session, Tokyo B session, andTokyo B' session, respectively. As shown in the appendix, the data from these three
sessions are statistically indistinguishable in virtually all cases. This provides strong
evidence that neither the experiment site (Tokyo versus Tsukuba) nor the experimentwording (“your opponent” versus “the person you are paired with”) affect choices.
Therefore, in the subsequent analysis we pool the data across the three Treatment B
sessions, i.e., Tsukuba B, Tokyo B, and Tokyo B' sessions.

5.1 Investment Data

9 This result is similar to Andreoni (1993) and Chan et al. (1998), who study the crowding out hypothesis in

public good experiments with an interior Nash equilibrium and minimum contribution “taxes” in sometreatments. In both of these previous experiments contributions were close to but slightly below the Nashequilibrium prediction when no tax was imposed.

12Figure 4 shows that the distribution of investment pairs in Treatment B are very
different from that of Treatment A (Figure 2). The maximum frequency pair was (8,7)
with 57 pairs, the second was (11,0) with 44 pairs, followed by (8,8) and (0,0) with 37 pairseach.
-------------------------------Figure 4 is around here-------------------------------Also unlike Treatment A, the average investment (including the investments ofzero by nonparticipants) changed across rounds in Treatment B. Figure 5 illustrates thatthe average investment in Treatment B was clearly less than in Treatment A, but the
average investment in Treatment B ascended across rounds. In the late rounds theaverage investments in the two Treatments were very similar; for example, in the final
round the average investments in Treatments A and B were 7.0 and 6.47 respectively. The
average investments were not significantly different by round between Treatments A and
B after round 4, according to the nonparametric two-sample Wilcoxon rank sum test.
-------------------------------Figure 5 is around here-------------------------------Using a random-effects panel data model that is the same as that for Treatment A,
we tested the hypothesis that mean investment equals the Nash equilibrium investment(8) in the case of both participating. The mean investment in this case was too low (7.26),
and we rejected the hypothesis (t=4.21).10 However, like the result for Treatment A, a
substantial number of subjects selected the Nash equilibrium, so the Nash equilibrium ismeaningful at least economically in the case of both participating.
10

For those who prefer nonparametric tests, we also conducted Wilcoxon signed rank tests separately for eachof the 15 periods. This test rejects the null hypothesis that average investment equals 8 at the five percent levelin 12 of the 15 periods.

13

5.2 Participation Data
We next examined whether the participation data in Treatment B were compatible
with the mixed strategy equilibrium of the Hawk-Dove game described in Table 1. The
null hypothesis is the ESS participation probability of 0.68. We first conducted a binomial
test separately by round in order to avoid pooling dependent participation decisions madeby the same subject in the same test. Under the ESS null hypothesis, the probability ofobserving 10 non-participation decisions or less out of 60 is less than one percent, and theprobability of observing 12 non-participation decisions or less out of 60 is less than five
percent. As Figure 6 shows, the participation rate rose as rounds advanced (although abrief decline was observed in rounds 8 and 9). The smooth curve is a simple log-linear
regression. More to the point for this binomial test, the low non-participation rate permits
the binomial test to reject the ESS null hypothesis in 9 rounds of the 15 total rounds (inrounds 5, 6, 7, 10, 11, 12, 13, 14, and 15) at the five percent (usually one percent)significance level.
-------------------------------Figure 6 is around here-------------------------------We also examined the overall participation rates for each of 60 subjects separately.
The mean participation rate was 80% (12 of 15 decisions), and the median participation
rate was 86.7% (13 of 15 decisions). Note that the ESS rate of 0.68 implies on averageslightly more than 10 participation decisions. Only 14 of the 60 subjects (23.3%)
participated 10 times or less, while the other 46 subjects (76.6%) participated 11 times ormore. 15 of the 60 subjects (25%) were apparently using a pure strategy, as they
participated in 15 out of 15 periods. Using the 60 separate subject observations, the data14

reject the ESS prediction of 0.68 at better than the 0.0001 significance level using the nonparametric Wilcoxon signed-rank test.
Furthermore, we conducted a binomial test of the mixed strategy of p = 0.68
separately for each subject. Under the null hypothesis that subjects play this mixed
strategy, participation decisions--even for an individual subject--are statisticallyindependent. At the five percent significance threshold, 23 of 60 subjects (38.3%)
participated too much (either 14 or 15 times), rejecting p = 0.68; 6 of 60 subjects (10%)
participated too little (7 times or less), rejecting p = 0.68 in the other direction. At the ten
percent significance threshold, 32 of 60 subjects (53.3%) participated too much (13, 14 or 15
times), rejecting p = 0.68; 9 of 60 subjects (15%) participated too little (8 times or less),
rejecting p = 0.68 in the other direction.

5.3 Why were Participation Ratios High?
In order to understand these rather high participation ratios, consider the case inwhich only one subject in a pair participated in the voluntary contribution mechanism.
When a subject did not participate in the mechanism, the other could obtain her
maximum units of payoff by investing 11 (see Table 2). There were 139 observations withexactly one participant. In these cases the participant invested eleven 43 times, invested
less than eleven 95 times (zero 17 times, invested one 3 times, invested two 7 times,
invested three 8 times, invested four 7 times, invested five 1 times, invested six 16 times,
invested seven 19 times, invested eight 9 times, invested nine 6 times, and invested ten 2times), and invested more than eleven (twenty-four) only 1 time. In fact, the mean
investment (6.90) was lower than when both subjects participated! Using a random effects

15

model, we soundly reject the hypothesis that mean investment equals 11 in the case of one
participant (t=8.14).11
As shown in Table 2, by investing 11 in response to the other not participating, thenon-participating subject earns 8278 while the participating subject earns 2658. On theother hand, by investing 7 in this situation, the non-participating subject earns 4018 while
the participating subject earns 2210. That is, the reduction of the participant's payoff(448=2658-2210) was relatively small, while the reduction of the non-participant's payoff(4269=8278-4018) was relatively large. This appears to be stronger evidence of spitefullike behavior than we observed in Treatment A. The “spite rate”, which is the ratio of thenumber of participants investing less than 11 to the number of observations with a single
participant, is equal to 95/139 = 68%.
One might say that in the two-stage game of Treatment B, the low investment by
the single participant could be interpreted as belonging to a tit-for-tat strategy to “teach”
others to cooperate. Because subjects were re-paired with a new opponent each period
and never interacted with the same subject in more than one period, however, such a
strategy is not subgame perfect. Furthermore, although there is no need to take a tit-for-tat
strategy at the final period of the experiment, the spite rate of the final period is equal to
6/9 = 67 percent.12
Our interpretation that this behavior is spiteful hinges on the low contributions
made by subjects when they are the only participant. An alternative interpretation ofaltruism is also consistent with our finding that the participation rate exceeds the ESS
prediction; altruistic subjects should always participate. Altruists, however, should also
11

The nonparametric Wilcoxon test rejects the null hypothesis that average investment equals 11 at the five
percent level in 9 of the 15 periods, even though the average sample size per period is only about 9 because of
the high participation rate.
12 The full distribution of the 9 final period observations with exactly one participant is as follows: one
participant invested two, one participant invested seven, three participants invested eight, one participant
invested nine, and three participants invested eleven.

16

invest as least as much as the level that maximizes their own earnings—which is 11 in thecase of a single participant—if not more, since the non-participant’s earnings strictlyincrease in the participant’s investment (see Table 2). Therefore, choices below 11 areinconsistent with pure altruism. These choices could, however, be consistent with notionsof “inequality aversion” or reciprocal altruism advanced recently by some researchers (forexample, see Fehr and Schmidt (1999) and Levine (1998)). What we refer to as spite in thiscontext is a response to the nonparticipation of one’s opponent, so it is a form of (negative)
reciprocity.13-------------------------------Figure 7 is around here-------------------------------Figure 7 shows average payoffs by round depending on participation.
Curve α denotes the average payoffs when both subjects participated in the mechanism.
As Table 1 shows, the payoff should be 7345 according to the Nash equilibrium prediction,
but actual data showed that average payoffs were less than 7000 units in all 15 rounds.
Curve β denotes the average payoffs when only the other participated in the mechanism.
According to the Nash equilibrium, this should lead to 8278 units of payoff, but actual
payoffs were less than 6000 in 12 of 15 rounds. According to Table 1, curve β should beabove curve α, but Figure 9 shows that curve α was above curve β in all but round 9. Thatis, participation became a dominant strategy even in early rounds, as illustrated in Table 5.

-------------------------------13

This is different from simple rivalistic behavior in which a subject seeks merely to earn more than his
opponent earns. The data are inconsistent with such rivalistic motivations, because such motivations are more
likely to lead to less participation than the ESS prediction since nonparticipation guarantees payoffs greaterthan or equal to those of the opponent. It is also unlikely that rivalistic choices would be so close to the Nashequilibrium when both subjects participate because rivalistic subjects have a strong incentive to reduce their
public good investment.

17

Table 5 is around here-------------------------------Our interpretation of this conversion to the dominant strategy game is based on
subject learning and proceeds roughly as follows. After inspection of the payoff tables,some subjects initially do not participate in the mechanism hoping the other will
participate and invest 11. They therefore expect (perhaps with the ESS probability of 0.68)
to receive a payoff of 8278. However, since their participating opponent invested less than11, the subject realized that her earnings in this subgame fell below 6000 on average. Afterlearning this, she chose to participate in the mechanism in later rounds and frequently
earned more than 6000.14

5.4 Learning Processes for Participation
Essentially, subjects learn (contrary to the ESS equilibrium) that expected profits
from participation tend to exceed those from non-participation. In this final subsection we
provide a simple model of this learning process. Many alternative approaches to learning
have been advanced recently in the literature, including reinforcement learning (e.g., Erev
and Roth, 1998), belief-based learning, and creative hybrid approaches (e.g., Camerer andHo, 1999). Rather than provide an exhaustive evaluation of the various learning models

14 As Figure 9 in the appendix shows, the average participation rates at early rounds in the Tokyo B session

were relatively high. To see why this happened, we looked at the record sheets for the four practice periods,
since the experiences of subjects in the practice periods might affect their participation decisions in the actual
experiment. We found that spiteful behavior during the practice periods would lead to high participation
rates in early periods. First of all, we counted the number of subjects who explicitly wrote that they realizedthat non-participation was not beneficial because the participant would act spitefully in the practice periods.
This number in the Tokyo B session (8) was much larger than both that in the Tokyo B’ session (1) and that in
the Tsukuba B session (1). We also calculated the number of subjects who had no chance to experience spiteful
behavior in the practice periods. Consider a subject who experienced the following: (a) no cases in which only
one subject participated, or (b) if only one subject participated (either himself or his opponent), the payoffmaximizing (non-spiteful) investment was selected. Call such a subject a "spite-free" subject. The number ofspite-free subjects in the Tokyo B session was 5, the number in the Tokyo B' session was 8, and at the numberin the Tsukuba B session was 11. As the number of spite-free subjects was larger, the participation rate atperiod 1 was smaller.

18

using our data, we simply report results of an adaptive, reinforcement-based learningmodel. In particular, we estimate a probit model in which the probability of participation
depends on the ratio of expected participation earnings (EPE) to expected nonparticipation earnings (ENE):(2)

Probability(Participation) = f(EPE/ENE)

The next step is to specify the process underlying subjects' expectations. We use
two polar cases for this simple model: (1) Cournot (or myopic) expectations and (2)Fictitious Play expectations (e.g., Cheung and Friedman, 1997; Cox and Walker, 1998).
According to Cournot, EPE are simply the realized earnings the last time thesubject participated; and ENE are simply the realized earnings the last time the subject did
not participate. In other words, subjects maintain a very short (myopic) memory length-of one observation for each (participate or not) decision. By contrast, according to
Fictitious Play, subjects have a long memory, and each observation updates the
expectation with a declining weight. For example, if a subject has participated N times up
to this round, and they participated in this round, they update EPE as follows:(3)

EPE=((N*previous EPE)+current participation earnings)/(N+1).

In other words, as subjects accumulate evidence they simply include it in their runningaverage of the payoffs from participation for EPE. ENE is, of course, analogous.15

15 For both Cournot and Fictitious Play, we need the expectations to start somewhere when no evidence has
yet accumulated. For these initial expectations we employ the ESS expected payoffs, which are 5829 for both
EPE and ENE. Therefore, the EPE/ENE ratio is 1 in round 1.

19

The empirical model is probit maximum likelihood, with a random subject effect.
Table 6 presents the estimation results separately and pooled for the three Treatment B
sessions. For Fictitious Play, the expected payoff ratio is insignificantly different fromzero except in the Tokyo B session, where the coefficient estimate has the wrong sign. For
the Cournot specification, the ratio is significantly positive except in the Tokyo B session.
The positive coefficient on the ratio implies that as the relative profitability ofparticipation increases, the likelihood of participation increases. So, we can conclude that(1) subjects' participation decisions respond to their experience, and (2) subjects appear to
update their expectations in this environment using a short (Cournot) memory length.
-------------------------------Table 6 is around here--------------------------------

Summarizing the above observations, we have the following.
Observation 2:(a)The ESS prediction regarding the participation ratio is rejected.
(b) The participation ratio rises as rounds advanced and the average investment in the final twothirds of Treatment B is not significantly different from that in Treatment A.
(c) It seems that the source of cooperation is not altruism or kindness but is spiteful behavior of
subjects. Subjects learn that non-participation will invoke a spiteful response, which reduces thepayoff of non-participation below the payoff of participation. This converts participation into adominant strategy.

6. Concluding Remarks
We found that the ESS prediction in a Hawk-Dove game was rejected and somecooperation among subjects emerged across time. Furthermore, this cooperation did not20

come from altruism or kindness among subjects, but from an optimal response to othersubjects' spiteful behavior. Acting spitefully in this way is costly, and this kind of spitefulor negative reciprocal behavior has also been observed recently by independent researchon public goods (Fehr and Gachter, 1998) and in the ultimatum game (Ochs and Roth,1989 and Prasnikar and Roth, 1992).
In neo-classical economic theory, it is assumed that each agent cares only about
himself and maximizes his own payoff subject to some constraints. If people care about
how they are doing relative to others (for example, see Hume, 1739),16 however, then it isnatural to think that they might often take spiteful actions in an attempt to decrease thehappiness of others. One would think that such spiteful behavior might result in outcomesthat are socially inferior to outcomes arising from the interaction of purely selfish
individuals. We find that the opposite may occur: spitefulness leads to greater cooperation.
This finding suggests a need to rethink our fundamental assumptions of human nature
underlying our models.
In our experiment, each subject knew that every subject had the same payoff table.
This might trigger spiteful behavior since every subject could understand opponent's
payoff structure. In future experiments we plan to conduct a systematic exploration ofthis information effect. It is also possible that spiteful behavior is more likely in twoperson games such as this because it encourages relative payoff comparison. Future
experiments can test this conjecture using larger groups. We also leave for future researcha comparison of American subjects to these Japanese subjects in the present environment.
If the propensity for spiteful behavior differs across cultures, outcomes could be
16“Now as we seldom judge of objects from their intrinsic value, but form our notions of them from acomparison with other objects; it follows, that according as we observe a greater or less share of happiness ormisery in others, we must make an estimate of our own, and feel a consequent pain or pleasure. The misery of
another gives us a more lively idea of our happiness, and his happiness of our misery. The former, therefore,
produces delight; and the latter uneasiness.” (David Hume, 1739)

21

substantially different for these two subject pools. Finally, the ESS participation rate in thepresent experiment was 0.68. We are currently conducting experiments in which the ratio
is less than 0.5.

22

APPENDIX: Comparisons of Tsukuba B, Tokyo B, and Tokyo B’ Sessions
First of all, we compare investments conditional on participation across the three B
and B’ sessions. Figure 8 illustrates how the average investment conditional onparticipation, which equals the sum of investment numbers for participants divided by
the number of participants, changed from round 1 to 15 for each of the three B and B’sessions. The average investments conditional on participation were different in only ahandful of periods according to the nonparametric Wilcoxon rank sum test. In 14 of the 15
periods there is no statistical difference between the Tokyo B and Tokyo B’ sessions at thefive percent significance level, which indicates that the “opponent” wording did not affectinvestments conditional on participation.17 Likewise, the Tokyo B and Tsukuba B sessions
are not statistically different in 12 of the 15 periods, indicating that investments
conditional on participation differed very little across sites.18-------------------------------Figure 8 is around here-------------------------------Figure 9 illustrates the average participation rate patterns from round 1 to 15 inTsukuba B session, Tokyo B session, and Tokyo B’ session. There are some statisticallysignificant differences in the participation rates between the Tsukuba B and Tokyo B

17 In period 8 the average investment in the Tokyo B’ session was significantly higher than in the Tokyo B

session.
18 The average investment was significantly higher in the Tsukuba B session in periods 1, 9 and 13.

23

sessions in periods 1 and 2.19 After period 2, there are basically no systematic differencesamong the participation rates across sessions.20-------------------------------Figure 9 is around here-------------------------------Overall, we conclude that there are virtually no statistically significant differencesin the data based on the experiment site or the experiment wording.

19 Fisher’s exact test p-values for the Tokyo B versus Tsukuba B comparison are 0.022 in period 1 and 0.020 inperiod 2. We discuss the reasons for these differences in footnote 12. Fisher’s exact test uses thehypergeometric probability distribution to calculate the exact probability of observing the distribution ofparticipation rates (and those more unequally distributed) under the null hypothesis of no differences in rates
across treatments.
20 In period 5 the participation rate is significantly higher in the Tokyo B’ session than in the Tokyo B session,
but in period 10 the participation rate is significantly lower in the Tokyo B’ session than in the Tokyo B session.

24

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27

1Participate

2
Participate

1
8

0

2

24

Not
participate

Not
participate Participate

2

1
11

11

(2658,8278)(8278,2658)

8(7345,7345)
Figure 1. The game tree when subjects canchoose their participation in the voluntary
contribution mechanism.

Not
participate(706,706)

p2
Participate
Participate

p1

1 Not

participate

1 - p12

1 - p2

Not
participate

7345
8278
2658
7345
706
2658
8278
706

Nash equilbrium:( p1, p2 ) = (10),, ( 0,1),( 0.68,0.68)
Evolutionarily stable strategy, ESS:

pi = 0.68
Table 1. The payoff table becomes a Hawk-Dove game.

Your Investment Number
Your

Your
Opponent's
Investment
NumberPayoff

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

0

706

871

1072

1297

1536

1775

2003

2210

2386

2523

2615

2658

2648

2585

2470

2309

2106

1871

1614

1349

1091

858

669

543

500

1

905

1127

1379

1647

1919

2183

2427

2641

2816

2944

3019

3039

3001

2905

2755

2555

2313

2038

1743

1443

1154

894

685

548

500

2

1186

1465

1764

2072

2374

2658

2913

3129

3297

3411

3465

3456

3385

3252

3061

2819

2534

2217

1881

1543

1220

933

703

552

500

3

1554

1888

2232

2575

2902

3202

3463

3675

3831

3925

3952

3911

3801

3626

3391

3102

2770

2406

2027

1648

1290

973

721

556

500

4

2017

2401

2787

3160

3508

3817

4078

4281

4420

4488

4483

4403

4250

4028

3743

3404

3020

2608

2181

1759

1363

1015

740

561

500

5

2578

3010

3432

3831

4193

4507

4762

4950

5064

5101

5057

4934

4733

4459

4119

3725

3287

2821

2344

1877

1441

1060

760

566

500

6

3244

3718

4171

4590

4960

5272

5515

5681

5766

5765

5677

5504

5249

4918

4519

4065

3568

3045

2516

2000

1522

1106

781

571

500

7

4018

4529

5008

5440

5812

6115

6339

6478

6526

6481

6343

6114

5800

5406

4944

4425

3866

3282

2696

2129

1607

1155

802

576

500

8

4904

5447

5944

6383

6751

7038

7237

7340

7345

7250

7056

6765

6385

5924

5393

4806

4179

3532

2886

2265

1696

1206

825

582

500

9

5907

6475

6984

7422

7779

8043

8209

8271

8225

8073

7816

7458

7007

6472

5867

5207

4508

3793

3084

2407

1789

1259

849

588

500

10

7031

7616

8130

8561

8897

9132

9257

9270

9168

8951

8624

8193

7664

7051

6367

5628

4854

4067

3292

2555

1886

1315

874

594

500

11

8278

8873

9384

9800 10109 10306 10384 10339 10173

9886

9482

8970

8359

7661

6892

6070

5217

4354

3509

2710

1987

1372

899

600

500

12

9653 10250 10750 11142 11416 11567 11589 11480 11242 10877 10390

9791

9090

8302

7444

6534

5596

4654

3736

2871

2092

1432

926

606

500

13

11158 11749 12229 12589 12820 12916 12875 12694 12376 11925 11349 10656

9860

8976

8022

7019

5992

4967

3972

3039

2201

1494

953

613

500

14

12796 13372 13824 14144 14323 14356 14243 13982 13576 13033 12358 11565 10667

9681

8627

7526

6406

5292

4217

3213

2315

1559

982

620

500

15

14570 15123 15538 15808 15925 15888 15694 15344 14844 14199 13420 12520 11514 10419

9258

8055

6836

5631

4473

3394

2433

1626

1012

627

500

16

16484 17003 17372 17583 17630 17513 17229 16783 16179 15426 14535 13521 12399 11191

9918

8606

7285

5984

4738

3582

2555

1695

1042

635

500

17

18539 19016 19328 19471 19439 19232 18850 18299 17583 16714 15704 14568 13324 11995 10605

9180

7751

6350

5013

3777

2681

1767

1074

642

500

18

20739 21163 21409 21474 21353 21047 20559 19893 19057 18064 16926 15661 14290 12834 11320

9776

8235

6730

5298

3978

2812

1841

1107

650

500

19

23086 23447 23617 23594 23374 22960 22355 21566 20602 19476 18203 16803 15296 13706 12063 10395

8737

7123

5593

4187

2947

1917

1141

659

500

20

25583 25870 25954 25832 25504 24972 24241 23319 22218 20951 19536 17992 16342 14614 12835 11038

9257

7531

5899

4403

3087

1996

1176

667

500

21

28231 28433 28420 28190 27743 27083 26217 25154 23907 22491 20924 19230 17431 15556 13636 11704

9796

7953

6214

4625

3231

2078

1212

676

500

22

31034 31141 31020 30670 30094 29296 28285 27071 25669 24095 22370 20516 18561 16533 14465 12393 10354

8388

6540

4855

3380

2162

1249

685

500

23

33993 33993 33753 33273 32557 31611 30445 29071 27505 25764 23872 21852 19733 17546 15325 13106 10930

8838

6877

5092

3533

2248

1287

694

500

24

37111 36993 36622 36001 35135 34030 32699 31155 29416 27500 25432 23239 20949 18595 16214 13843 11525

9303

7224

5337

3691

2337

1326

703

500

Table 2. Detailed Payoff Table

Your Investment Number
Your
Payoff

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

0
1
2

1484

2446

3066

3246

2902

2127

1200

581

3245

4512

5057

4921

4109

2821

1460

609

5705

7036

7332

6749

5383

3536

1724

636

9122

10295

10154

8952

6883

4364

2024

667

13575

14338

13553

11545

8620

5310

2364

701

19132

19206

17555

14548

10603

6376

2743

739

25855

24939

22187

17973

12838

7567

3163

781

33800

31573

27472

21836

15336

8887

3626

827

3
4
5

Your
Opponent's
Investment
Number

6
7
8
9
10

11
12
13

14
15
16
17

18
19

20
21
22

23
24

Table 3. Rough Payoff Table

24

Your Investment Number
0

0

2

4

6

8

10

12

14

16

18

20

2
4
2000

6
4000

8

Your
Opponent's
Investment
Number

6000
8000

10
10000

12

12000

14

14000
16000

16
18

22000
24000

20

26000
28000

22
24

32000

34000
Table
4. Iso-Payoff Map
36000

Table 4. Iso-Payoff Map

22

24

40
35
30
25
20
15
10
5
0

16

14

12

Smaller
Investment

10

8

6

4

2

0 0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

LargerInvestment

Figure 2. Investment Pattern in Treatment A

15

16

Frequency

8
7

Average Investment

6543Nash equilibrium
all data
data without spite

2
1
0
1

2

3

4

5

6

7

8

9

10

11

PeriodFigure 3. Average Investments in Treatment A.

12

13

14

15

60
50
40
30
20
10
0

14

12

Smaller
Investment

10

8

6

4

2

0 0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

LargerInvestment

Figure 4. Investment Pattern in the Three Treatment B Sessions.

Frequency

8.00

7.00

Average Investment

6.00

5.00

y = 0.5385Ln(x) + 4.7478
2
R = 0.4859

4.00

3.00
Treatment A with no participation decision

2.00

Treatment B with participation decisions (pooled)
Trend (Treatment with participation decisions)

1.00

0.00
1

2

3

4

5

6

7

8
Period910

Figure 5. Comparison of Average Investment Patterns:
Treatment A versus Treatment B.

11

12

13

14

15

1.00

0.90

(Number of Participants)/(Number of Subjects)

0.80

0.70

y = 0.0643Ln(x) + 0.6804
2
R = 0.479

0.60

0.50

0.40

0.30

0.20

0.10

0.00
1

2

3

4

5

6

7

8

9

PeriodFigure 6. Participation Rate Pattern.

10

11

12

13

14

15

Both participate.
I do not participate, but the other does.
I participate, but the other does not.
Neither participates.

8000
7000

a

Average Payoff

6000
5000

b

4000
3000
2000
1000
0
1

2

3

4

5

6

7

8

9

10

11

12

PeriodFigure 7. Average Payoffs by Participation Decision.

13

14

15

p2
Participate
Participate

1 Not

p1

participate

1 - p12

1 - p2

Not
participate

6570
4795
2049
6570
706
2049
4795
706

Table 5. The average values of payoff data up to round 5
for the three treatment B sessions.

Dependent Variable = 1 if Participate
0 if Not Participate
Probit Model with random subject effectVariable or Statistic
Expected Participation Earnings/
Expected Non-Participation Earnings
InterceptaRho

Number of Observations
Estimated Log-likelihood
Restricted (slopes=0) Log-likelihood

Model (1): Cournot Expectations
TsukubaTokyo
Tokyo
B and B’B
B
B’
Pooled
0.051*-0.0440.086**
0.028*(0.022)(0.043)(0.031)(0.015)0.618**
1.279**
1.126**
1.010**(0.187)(0.224)(0.241)(0.115)0.382*
0.339
0.447*
0.344**(0.165)(0.221)(0.191)(0.100)
300
300
300
900
-147.3-123.7-129.8-405.6-161.6-136.5-145.8-450.1Model (2): Fictitious Play Expectations
TsukubaTokyo
Tokyo
B and B’B
B
B’
Pooled-0.013-0.132*0.131-0.002(0.054)(0.064)(0.193)(0.025)0.915**
1.312**
0.935**
1.073**(0.211)(0.240)(0.222)(0.120)0.280*
0.371*
0.382*
0.333**(0.137)(0.176)(0.193)(0.094)
300
300
300
900
-149.0-122.7-130.0-406.7-161.6-136.5-145.8-450.1

Standard errors in parentheses.
* denotes significantly different from zero at the 5-percent level; ** denotes significantly different from zero at the 1-percent level (all twotailed tests except for Expected Participation Earnings/Expected Non-Participation Earnings).
a
Rho is a standard Hausman test statistic for the presence of random effects.

Table 6. Results of Probit Participation Model10.00

9.00

Average Investment Conditional on Participation

8.00

7.00

6.00

5.00

4.00

3.00
Tokyo B

Tokyo B'

Tsukuba B

2.00

1.00

0.00
1

2

3

4

5

6

7

8
Period910

Figure 8. The Average Investment Patterns Conditional on Participationin Tsukuba B, Tokyo B, and Tokyo B' Sessions.

11

12

13

14

15

1.00

0.90

(Number of Participants)/(Number of Subjects)

0.80

0.70

0.60

0.50

0.40

0.30

Tokyo B

Tokyo B'

Tsukuba B

0.20

0.10

0.00
1

2

3

4

5

6

7

8
Period910

Figure 9. The Average Participation Rate Patterns
in Tsukuba B, Tokyo B, and Tokyo B' Sessions.

11

12

13

14

15

Instruction Sheets and Data
Tatsuyoshi Saijo, Takehiko Yamato, Konomu Yokotani, and Timothy N. Cason
Revised: December 1998
1. Instruction Sheets for Treatment A
1.1. Overview ………………………………………………………………………...3
1.2. Experiment Procedure ………………………………………………………….7
1.3. Instructions for Payoff Tables ………………………………………………….9
1.4. Investment Card ……………………………………………………………….12
1.5. Record Sheet ……………………………………………………………………13
1.6. Questionnaires on the Experiment …………………………………………..15
1.7. Payoff Tables …………………………………………………………………...19
a. Payoff Table 1 (for practice)b. Payoff Table 2 (for practice)c. Payoff Table 3 (for practice)d. Payoff Table 1 (for the actual experiment)e. Payoff Table 2 (for the actual experiment)
f. Payoff Table 3 (for the actual experiment)
2. Instruction Sheets for Treatment B
2.1. Overview ……………………………………………………………………….25
2.2. Experiment Procedure ………………………………………………………...312.3. Instructions for Payoff Tables ………………………………………………...34
2.4. Investment Card ……………………………………………………………….41
2.5. Record Sheet ……………………………………………………………………42
2.6. Questionnaires on the Experiment ….……………………………………….49
2.7. Payoff Tables …………………………………………………………………...53
a. Payoff Table 1 (for practice)b. Supplemental Payoff Table 1-1 (for practice)c. Supplemental Payoff Table 1-2 (for practice)d. Payoff Table 2 (for practice)e. Supplemental Payoff Table 2-1 (for practice)f. Supplemental Payoff Table 2-2 (for practice)g. Payoff Table 3 (for practice)h. Supplemental Payoff Table 3-1 (for practice)i. Supplemental Payoff Table 3-2 (for practice)j. Payoff Table 1 (for the actual experiment)k. Supplemental Payoff Table 1-1 (for the actual experiment)l. Supplemental Payoff Table 1-2 (for the actual experiment)
m. Payoff Table 2 (for the actual experiment)
n. Supplemental Payoff Table 2-1 (for the actual experiment)o. Supplemental Payoff Table 2-2 (for the actual experiment)
p. Payoff Table 3 (for the actual experiment)
q. Supplemental Payoff Table 3-1 (for the actual experiment)r. Supplemental Payoff Table 3-2 (for the actual experiment)

1

3. Data for the Tsukuba A Session
3.1. Pairs of Subjects (ID Numbers) ………………………………………………71
3.2. Investment Numbers of Each Subject ……………………………………….71
3.3. Investment Numbers of Each Subject’s Opponents ……………………….72
3.4. Pairs of Investment Numbers ………………………………………………..73
3.5. Payoffs of Each Subject ……………………………………………………….74
3.6. Record Sheets and Questionnaires ………………………………………….75
4. Data for the Tsukuba B Session (with the “Opponent” Wording)
4.1. Pairs of Subjects (ID Numbers) ……………………………………………..115
4.2. Participation Decisions of Each Subject ……………………………………115
4.3. Participation Decisions of Each Subject’s Opponents ……………………115
4.4. Investment Numbers of Each Subject ……………………………………...116
4.5. Investment Numbers of Each Subject’s Opponents ………………………116
4.6. Pairs of Investment Numbers ……………………………………………….117
4.7. Payoffs of Each Subject ………………………………………………………118
4.8. Record Sheets and Questionnaires …………………………………………119
5. Data for the Tokyo B Session (with the “Opponent” Wording)
5.1. Pairs of Subjects (ID Numbers) ……………………………………………..199
5.2. Participation Decisions of Each Subject ……………………………………199
5.3. Participation Decisions of Each Subject’s Opponents ……………………199
5.4. Investment Numbers of Each Subject ……………………………………...200
5.5. Investment Numbers of Each Subject’s Opponents ………………………200
5.6. Pairs of Investment Numbers ……………………………………………….201
5.7. Payoffs of Each Subject ………………………………………………………202
5.8. Record Sheets and Questionnaires …………………………………………203
6. Data for the Tokyo B’ Session (without the “Opponent” Wording)
6.1. Pairs of Subjects (ID Numbers) ……………………………………………..283
6.2. Participation Decisions of Each Subject ……………………………………283
6.3. Participation Decisions of the Persons Each Subject was Paired with ….283
6.4. Investment Numbers of Each Subject ……………………………………...284
6.5. Investment Numbers of the Persons Each Subject was Paired with ……284
6.6. Pairs of Investment Numbers ……………………………………………….285
6.7. Payoffs of Each Subject ……………………………………………………....286
6.8. Record Sheets and Questionnaires …………………………………………287

2

A

A

1. Instruction Sheets for Treatment A
The "Record Sheet" is for the record of your information in the experiment. You
1.1 Overview

will record "Your Investment Number," the "Reason for Your Decision on Investment
Number," "Your Opponent's Investment Number," and "Your Payoff" in the "Record

In each period, you will receive 24 units of money. This money is not real

Sheet."

money, but please imagine that you have 24 units of money. You can determine thenumber of units for investment out of 24. One of subjects will be your opponent. An
experimenter will choose your opponent from the subjects at random.

The "Investment Card" is to write the investment number that you have chosen
and inform it to your opponent. In the upper side of the "Investment Card," the sentenceFirst, you decide how many units of money out of 24 you invest and then record"Your opponent's ID Number ¨" is written. This is the ID number of your opponent inyour investment number in the "Investment Card." An experimenter will collect thethe present period. In the lower side of the "Investment Card", the sentence "Your ID"Investment Cards." Your "Investment Card" will be distributed to your opponent, andnumber is __" is written. This indicates your ID number.

your opponent's "Investment Card" will be distributed to you.

In your opponent's"Investment Card," your opponent's investment number is recorded, so that you know

"Payoff Table 1" specifies how much your payoff is for each pair of your

your opponent's investment number. Your payoff is determined by your investment

investment number and your opponent's investment number. "Payoff Table 2" andnumber as well as your opponent's investment number. You can see how much your

"Payoff Table 3" are to help your understanding of "Payoff Table 1." The same three

payoff is by looking at the payoff table.

tables are distributed to all subjects. An experimenter will explain these tables according

This is one period. This experiment consists of 4 periods of practice and then 15

to "Instructions for Payoff Tables" later. The blue "Payoff Tables" that you have now areperiods of the actual experiment. Your opponent in the next period is randomly chosen

for practice. The "Payoff Tables" for the actual experiment are red and they will beby an experimenter, and your opponent changes in each period. In the following, thedistributed to you after the practice periods.

instructions for the experiment are explained in detail. If you follow instructions closely
and make investment decisions carefully, you can receive reasonable earnings. Yourearnings are determined according to your payoff and will be paid to you after the

Let me explain the detailed procedures of the experiment.
You will select investments for 4 practice periods and then for 15 actual
experiment periods. The units of money you have in the beginning of each period are 24

experiment. How to compute your earnings will be explained later.
From now on, please remember that you cannot talk to other subjects. If thisand they are the same for all subjects. One of the subjects is your opponent. You andyour opponent play an investment game. You make an investment decision based on

happens, the experiment will be stopped at that point.

"Payoff Tables 1, 2, and 3." You choose an investment number from 0 to 24 and circle thenumber that you chose in the "Investment Card." You also record this number in theInstructions

column of "Your Investment Number" in the "Record Sheet." An experimenter collectsthe "Investment Cards." Your "Investment Card" is distributed to your opponent, andFirst, please confirm the following items on your desk.

your opponent's "Investment Card" is distributed to you. Please answer the question of
× Overview (this set of papers)

× Experiment Procedure

× Record Sheet× Investment Cards (19 sheets)

× Payoff Tables for Practice (3 sheets)

the experimenter collects and distributes the "Investment Cards." Please specify what

× Instructions for Payoff Tables

× Pencil and eraser

you expected your opponent's investment decision and why you chose your investment

the "Reason for Your Decision on Your Investment Number" in the "Record Sheet," whilenumber based on your expectation.
The "Experiment Procedure" summarizes what subjects should do in theexperiment. Please take a look at it if necessary.
3

When your opponent's "Investment Card" isdistributed to you, please write your opponent's investment number in the column of"Your Opponent's Investment Number" in the "Record Sheet."4

Please insert theAA"Investment Card" into the envelope beside your desk after you finish writing. "Yourinvestment number" as well as "Your opponent's investment number" have been

The equations for computing "Your Payoff":

recorded in the "Record Sheet." Find "Your Payoff" according to "Payoff Tables." "Payoff
Table 1" indicates how much "Your Payoff" is, depending on "Your Investment Number""Your Payoff" depends on your investment number and your opponent's investment

and "Your Opponent's Investment Number". The equation for how to compute yournumber. In practice, your payoff is calculated as follows:

payoff is described at the end of this overview. After checking "Your Payoff," write it in{(24 - a)0.467 ´ (a + b)1-0.467 }Your payoff =the column of "Your Payoff" in the "Record Sheet."This is the end of one period. In the next period, an experimenter will choose"Instructions for Payoff Tables."+ 500 ,

50

your opponent at random. You will face a different opponent in each period.
Next let me explain how to read the payoff tables. Please take a look at the

4.4

where a denotes your investment number and b stands for your opponent's investment
number.

For example, suppose that "Your Investment Number" is 8 and "Your

Opponent's Investment Number" is 10. Then "Your Payoff" is 5737 since

Now let me explain about your earnings. Your earnings depend only on thesum of "Your Payoffs" in the actual experiment, but not on your payoffs in the first 4

Your payoff =periods of practice. Your earnings are computed in the following way:Your earnings = (the sum of "Your Payoffs" in the actual experiment) ´ 0.025 yen
For example, suppose that the sum of "Your Payoffs" in the actual experiment is 99,970.
Then your earnings are 2,499 yen since 99,970 ´ 0.025 = 2499. Fractions are rounded off

The "Payoff Tables" for the actual

experiment will be distributed afterward. You will have ten minutes for looking at the50

In the actual experiment, your payoff is determined according to thefollowing equation:{(24 - a)0.47 ´ (a + b + 3)1-0.47 }Your payoff =50

4 . 45+ 500 ,

where a denotes your investment number and b stands for your opponent's investment
number.

"Payoff Tables" for the actual experiment before it starts.
You must understand the procedure of the experiment as well as how to readthe payoff tables completely. If you have any questions, please ask an experimenter.
However, do not talk to other subjects. Please follow experimenters' instructions.
Please see the following equations if you are interested in how to compute yourpayoff.

5+ 500 » 5737 .

tables.

You will have three minutes for looking at the "Payoff Tables" for practicepractice into the envelope beside your desk.

4.4

Fractions are rounded off to one decimal place for all numerical values in the payoff

to the nearest yen.

before 4 periods of practice begin. After the practice periods, put the "Payoff Tables" for{(24 - 8)0.467 ´ (8 + 10)1-0.467 }6

A
1.2. Experiment ProcedureA
Investment Number" in the "Record Sheet."· Take off the top sheet of the bunched "Investment Cards" and put it up-side-down on(1) Instructions for the experiment

your table.
· While an experimenter collects and redistributes "Investment Cards", fill out the(2) Practicecolumn of the "Reason for Your Decision on Investment Number."· An experimenter instructs subjects that "You have 3 minutes to look at payoff tables."· When your opponent's "Investment Card" is distributed to you, write your opponent's· After 3 minutes, an experimenter instructs subjects that "You will select investments

investment number in the column of "Your Opponent's Investment Number" in thefor 4 practice period. Let us start the first period.""Record Sheet."· Decide your investment number and circle the number that you have chosen in the· Put the "Investment Card" into the envelope beside your desk.

"Investment Card."· Find your payoff by looking at "Payoff Table 1" and write it in the column of "Your· Write the circled number in the "Investment Card" into the column of "YourPayoff" in the "Record Sheet."

Investment Number" in the "Record Sheet."· An experimenter instructs subjects that "Let us start the second period in the actual· Take off the top sheet of the bunched "Investment Cards" and put it up-side-down on

experiment".

your table.

* The actual experiment consists of 15 periods. The above procedure is repeated 15· While an experimenter collects and redistributes "Investment Cards," fill out thetimes.

column of the "Reason for Your Decision on Investment Number."* Please follow experimenter's instructions after the fifteenth period.

· When your opponent's "Investment Card" is distributed to you, write your opponent's
investment number in the column of "Your Opponent's Investment Number" in the(4) After the experiment"Record Sheet."· Experimenters collect the "Record Sheets."· Put the "Investment Card" into the envelope beside your desk.

· Experimenters distribute the "Personal Information Sheet and Receipt" and the sheet of· Find your payoff by looking at "Payoff Table 1" and write it in the column of "Your"Questionnaires on the Experiment." Please fill out your name, address, and etc. in the

Payoff" in the "Record Sheet.""Personal Information Sheet and Receipt." Also, please answer questions in the sheet of· An experimenter instructs subjects that "Let us start the second period for practice.""Questionnaires on the Experiment."* Practice consists of 4 periods. The above procedure is repeated 4 times.

· The earnings are paid one by one. Please wait until your name is called.

* After practice, an experimenter instructs subjects that "Please put the "Payoff Tables"· After receiving your earnings, please fill out the receipt.

for practice into the envelope beside your desk."
An experimenter distributes "Payoff Tables" for the actual experiment.
(3) The actual experiment· An experimenter instructs subjects that "You have 10 minutes to look at payoff tables."· After 10 minutes, an experimenter instructs subjects that "You will selects investments
for 15 actual experiment periods. Let us start the first period of the actual experiment".
· Decide your investment number and circle the number that you have chosen in the"Investment Card."· Write the circled number in the "Investment Card" into the column of "Your
7

8

A

A

1.3. Instructions for Payoff Tables
Payoff Table 2 (for Practice)
There are three kinds of payoffs tables. The same three tables are distributed toYour Investment Number

all subjects. Also, "Your Payoff" in the experiment is determined only by "Payoff Table0

1." "Payoff Table 2" and "Payoff Table 3" are to help your understanding of "Payoff Table
1."(1) Instructions for "Payoff Table 1""Payoff Table 1" specifies "Your Payoff," depending on "Your Investment
Number" and "Your Opponent's Investment Number." In this table, the column denotes

1

Opponent's

2

Investment

3

Number4
5

is, 1,613.

3

4

5

6

712

1216

1500

2390

6

For example, if "Your Investment Number" is 5 and "Your Opponent's

Investment Number" is 3, "Your Payoff" is the number in the cell of column 5-row 3, that

2

0
Your

"Your Investment Number" and the row denotes "Your Opponent's Investment
Number."1

Next let me explain the meaning of the symbol "<" in this table. This symbol
indicates which numbers in the neighbor are larger. A number in the open side of thesymbol is larger than a number in the other side. For example, let us compare 712 andPayoff Table 1 (for practice)

1,216 in "Payoff Table 2." Since 712 is smaller than 1,216, 1216 is located in the open sideYour Investment Number
0

1

2

3

4

5

of the symbol. Also, since 1,216 is smaller than 2309, 2309 is located in the open side of

6

Your

0

500

513

558

637

743

870

1007

Opponent's

1

514

564

651

769

911

1067

1228

Investment

2

570

665

796

954

1130

1314

1496

Number

3

680

824

1000

1196

1404

1613

1813

the symbol.
(3) Instructions for "Payoff Table 3"
In "Payoff Table 3", the horizontal axis denotes "Your Investment Number" andthe vertical axis denotes "Your Opponent's Investment Number."

Payoff levels are

represented by contours in this table. Payoff levels increase in the south-west direction.

(2) Instruction for "Payoff Table 2""Payoff Table 2" is a rough version of "Payoff Table 1." In this table, the column
denotes "Your Investment Number" and the row denotes "Your Opponent's Investment
Number," as in "Payoff Table 1." However, the number in a large cell of this table is theaverage values of the numbers in the corresponding cells of "Payoff Table 1."

For

example, consider the case in which "Your Investment Numbers" are from 4 to 6 and"Your Opponent's Investment Numbers" are from 0 to 3. Please see the above "Payoff
Table 1." There are three "Your Investment Numbers," 4, 5, and 6, in "Payoff Table 1."

For example, consider the case in which "Your Investment Number" is 10 and "Your
Opponent's Investment Number" is 6. In the following table, draw a vertical line downfrom "Your Investment Number" 10 and a horizontal line from "Your Opponent's
Investment Number" 6 to the right. The intersection of these two lines denotes "YourPayoff." This intersection lies between the contour 3,000 and the contour 4,000. Thismeans that your payoff is a value between 3,000 and 4,000. You will find that yourpayoff is 3,520 by looking at "Payoff Table 1."

On the other hand, there are four "Your Opponent's Investment Numbers," 0, 1, 2, 3.
Therefore, in total, there are 3 ´ 4 = 12 numbers in "Payoff Table 1." Next please see thefollowing "Payoff Table 2." The number in the shaded cell of "Payoff Table 2" is 1,216.
This is the average value of 12 numbers in the corresponding cells of "Payoff Table 1."

9

10

A
Payoff Table 3 (for Practice)A
1.4. Investment CardYour Investment Number
The Actual ExperimentYour opponent's ID number is

Period 1

Please circle your investment number.

Your
Opponent’s
Investment
Number

0
14

1

2
15

3

4

5

16

17

18

6

7

8

9

10

11

12

19

20

21

22

23

24

Your ID number is _____.

This is the end of instructions for three payoff tables.

11

12

13

A

A

Your
The Reason for Your Decision on Your Investment Number
Your
Investment (Please specify your expectation on your opponent's Opponent's
Number investment number and the reason why you chose your Investment
Numberinvestment number.)

1.5. Record Sheet
PracticeYour
The Reason for Your Decision on Your Investment Number
Your
Investment (Please specify your expectation on your opponent's Opponent's
Number investment number and the reason why you chose your Investment
investment number.)NumberYour
PayoffPeriod 1

Period 5(White)Period 6(White)(Red)

Period 2

Period 7(Red)(Blue)

Period 3

Period 8(Blue)(Yellow)

Period 4

Period 9(Yellow)(White)The parenthesis under the number of period indicates the color of the investment card.
Period 10(Red)
The Actual ExperimentYour
The Reason for Your Decision on Your Investment Number
Your
Investment (Please specify your expectation on your opponent's Opponent's
Number investment number and the reason why you chose your Investment
investment number.)NumberPeriod 11
Your
Payoff(Blue)

Period 1

Period 12(White)(Yellow)

Period 2

Period 13(Red)(White)Period 3

Period 14(Blue)(Red)

Period 4

Period 15(Yellow)(Blue)Your ID number is

13

14

Your
Payoff

A
1.6. Questionnaires on the ExperimentA(4) This question is to ask your investment behavior. Which of the following is closest to
your way of thinking on investment decisions? Choose one of the following.

ID Number
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
2. If my payoff is higher than my opponent's payoff, I do not care about theabsolute value of my payoff, even when the difference between my payoff and my

Please answer the following questions.

opponent's is small.
(1) Did you understand the rules of the experiment? Please circle one of the numbers of
the following answers. If you choose 2, circle either "Practice" or "Actual Experiment"
and write the number of period from which you have understood the rules.

3. It is desirable that both my payoff and my opponent's payoff are as high as
possible.
4. If I can make my opponent's payoff as small as possible, it is fine that my
payoff is moderate.

1. I have understood the rules from the beginning of the experiment.
2. I have understood the rules from a middle of the experiment:
From period () in Practice ž Actual Experiment

5. If my payoff is the same as my opponent's payoff, I do not care about theabsolute value of my payoff.
6. Others (please specify).

3. I could not understand the rules.
(2) Did you understand the three payoff tables? Please circle one of the numbers of thefollowing answers. If you choose 2, write the numbers of the payoff tables that you
could not understand.
(5) What did you think about your opponent's investment? Please choose one of the

1. I understood all three tables.
2. I could not understand payoff table ().

following.

(3) Did you notice anything about the three payoff tables? Which tables did you take a

1. I always expected how much my opponent invests.

look at when you decided your investment number? Please answer these questions

2. I did not think about it in particular.

concretely as much as you can.
(6) This is the question for the one who chose 1. in (5). How often did your expectations
come true?
1. All expectations came true.
2. () % of expectations came true.

3. No expectation came true.

15

16

A

A

(7) Did you notice anything about your opponents' investment numbers? How did you
behave in response to them? Please answer these questions concretely as much as youcan.

(8) Finally, what would be the best choice for your investment? What do you think fromyour experience in the experiment? Why? Please answer these questions concretely as
much as you can.

Please confirm that your ID number is filled in again.
Thank you very much.

17

18

1.7a. Payoff Table 1 (for Practice)Your Investment Number

Your
Payoff

0

1

2

3

4

5

0

500

513

558

637

743

1

514

564

651

769

Your

2

570

665

796

954 1130 1314 1496 1667 1820 1945 2038 2094 2109 2081 2013 1904 1761 1588 1394 1189

Opponent's

3

680

Investment

4

Number

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

870 1007 1148 1282 1403 1503 1577 1621 1631 1606 1547 1456 1338 1198 1045

888

741

617

531

500

911 1067 1228 1386 1531 1656 1754 1821 1852 1845 1800 1718 1602 1458 1292 1114

936

769

630

535

500

986

798

643

538

500

824 1000 1196 1404 1613 1813 1995 2150 2272 2356 2396 2391 2340 2244 2106 1931 1727 1502 1268 1039

830

658

542

500

854 1047 1266 1500 1737 1967 2181 2369 2524 2638 2708 2729 2700 2621 2494 2323 2114 1875 1617 1353 1096

863

673

545

500

1097 1340 1600 1867 2130 2379 2602 2792 2942 3044 3096 3093 3036 2925 2763 2556 2310 2034 1740 1442 1156

898

689

550

500

6

1416 1705 2004 2302 2587 2849 3078 3266 3405 3491 3520 3490 3400 3253 3053 2805 2518 2202 1870 1537 1219

935

706

554

500

7

1815 2148 2483 2807 3110 3381 3610 3790 3915 3980 3981 3918 3792 3605 3362 3071 2740 2381 2008 1637 1285

973

723

558

500

8

2299 2673 3039 3385 3701 3976 4201 4368 4473 4512 4481 4381 4213 3981 3692 3353 2975 2570 2153 1742 1355 1014

742

563

500

9

2871 3282 3675 4039 4362 4635 4850 5000 5080 5087 5019 4877 4663 4383 4043 3653 3224 2770 2306 1853 1428 1057

761

568

500

10

3536 3978 4393 4769 5095 5362 5561 5688 5737 5707 5596 5407 5143 4809 4415 3969 3486 2980 2467 1969 1505 1101

781

573

500

11

4296 4766 5197 5580 5902 6156 6335 6432 6446 6373 6214 5973 5653 5262 4808 4304 3762 3200 2636 2090 1586 1148

803

578

500

12

5156 5647 6089 6472 6785 7020 7172 7234 7206 7085 6873 6574 6194 5740 5223 4656 4053 3432 2813 2217 1670 1196

824

584

500

13

6117 6624 7071 7447 7745 7956 8074 8095 8018 7844 7573 7212 6766 6245 5660 5026 4358 3675 2998 2350 1757 1247

847

589

500

14

7183 7699 8144 8509 8784 8963 9042 9016 8885 8651 8316 7886 7370 6777 6120 5414 4677 3928 3191 2488 1848 1299

871

595

500

15

8357 8875 9312 9658 9904 10045 10077 9997 9806 9506 9101 8598 8005 7335 6602 5820 5011 4193 3392 2633 1943 1354

896

601

500

16

9641 10155 10576 10896 11106 11202 11181 11041 10783 10411 9930 9347 8673 7922 7107 6246 5359 4470 3602 2783 2042 1410

921

608

500

17

11037 11540 11939 12225 12392 12436 12355 12147 11816 11366 10802 10135 9375 8536 7635 6690 5723 4758 3820 2938 2144 1469

948

614

500

18

12549 13033 13401 13646 13763 13748 13599 13318 12907 12371 11719 10961 10109 9178 8186 7153 6102 5057 4047 3100 2250 1530

975

621

500

19

14178 14635 14965 15161 15220 15138 14915 14552 14055 13428 12682 11827 10877 9849 8761 7636 6496 5368 4282 3268 2360 1593 1003

628

500

20

15926 16348 16632 16772 16765 16609 16304 15853 15262 14537 13690 12732 11679 10549 9360 8138 6905 5691 4526 3442 2474 1658 1033

635

500

21

17796 18175 18405 18480 18399 18161 17766 17220 16528 15699 14744 13678 12516 11277 9984 8659 7330 6026 4779 3622 2591 1725 1063

643

500

22

19790 20117 20284 20287 20124 19795 19304 18654 17854 16914 15845 14664 13387 12035 10631 9201 7771 6374 5041 3808 2713 1795 1094

651

500

23

21910 22176 22272 22193 21940 21513 20916 20156 19241 18182 16993 15691 14294 12823 11304 9762 8228 6733 5311 4000 2839 1867 1126

659

500

24

24157 24354 24369 24201 23849 23315 22606 21727 20690 19506 18190 16760 15236 13641 12001 10344 8701 7104 5591 4199 2968 1941 1159

667

500

23

24

19

1.7b. Payoff Table 2 (for Practice)Your Investment Number
Your
Payoff

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

0
1
2
Your

3

Opponent's

4

Investment

5

Number

6

712

1216

1688

1959

1903

1521

967

558

1500

2390

2941

3086

2755

2031

1166

580

2876

3981

4467

4369

3683

2570

1372

602

4990

6154

6434

5959

4798

3203

1609

627

7916

8954

8869

7870

6111

3936

1880

656

11720

12420

11796

10117

7628

4771

2185

687

16456

16586

15237

12714

9357

5712

2526

723

22176

21485

19214

15673

11305

6762

2903

762

7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

20

1.7c. Payoff Table 3 (for practice)Your Investment Number

Your
Opponent's
Investment
Number21

1.7d. Payoff Table 1 (for the Actual Experiment)
Your Investment Number
Your
Payoff

0

1

0

706

1
Your

2

Opponent's

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

871 1072 1297 1536 1775 2003 2210 2386 2523 2615 2658 2648 2585 2470 2309 2106 1871 1614 1349 1091

858

669

543

500

905 1127 1379 1647 1919 2183 2427 2641 2816 2944 3019 3039 3001 2905 2755 2555 2313 2038 1743 1443 1154

894

685

548

500

1186 1465 1764 2072 2374 2658 2913 3129 3297 3411 3465 3456 3385 3252 3061 2819 2534 2217 1881 1543 1220

933

703

552

500

3

1554 1888 2232 2575 2902 3202 3463 3675 3831 3925 3952 3911 3801 3626 3391 3102 2770 2406 2027 1648 1290

973

721

556

500

Investment

42017 2401 2787 3160 3508 3817 4078 4281 4420 4488 4483 4403 4250 4028 3743 3404 3020 2608 2181 1759 1363 1015

740

561

500

Number52578 3010 3432 3831 4193 4507 4762 4950 5064 5101 5057 4934 4733 4459 4119 3725 3287 2821 2344 1877 1441 1060

760

566

500

6

3244 3718 4171 4590 4960 5272 5515 5681 5766 5765 5677 5504 5249 4918 4519 4065 3568 3045 2516 2000 1522 1106

781

571

500

7

4018 4529 5008 5440 5812 6115 6339 6478 6526 6481 6343 6114 5800 5406 4944 4425 3866 3282 2696 2129 1607 1155

802

576

500

8

4904 5447 5944 6383 6751 7038 7237 7340 7345 7250 7056 6765 6385 5924 5393 4806 4179 3532 2886 2265 1696 1206

825

582

500

9

5907 6475 6984 7422 7779 8043 8209 8271 8225 8073 7816 7458 7007 6472 5867 5207 4508 3793 3084 2407 1789 1259

849

588

500

10

7031 7616 8130 8561 8897 9132 9257 9270 9168 8951 8624 8193 7664 7051 6367 5628 4854 4067 3292 2555 1886 1315

874

594

500

11

8278 8873 9384 9800 10109 10306 10384 10339 10173 9886 9482 8970 8359 7661 6892 6070 5217 4354 3509 2710 1987 1372

899

600

500

12

9653 10250 10750 11142 11416 11567 11589 11480 11242 10877 10390 9791 9090 8302 7444 6534 5596 4654 3736 2871 2092 1432

926

606

500

13

11158 11749 12229 12589 12820 12916 12875 12694 12376 11925 11349 10656 9860 8976 8022 7019 5992 4967 3972 3039 2201 1494

953

613

500

14

12796 13372 13824 14144 14323 14356 14243 13982 13576 13033 12358 11565 10667 9681 8627 7526 6406 5292 4217 3213 2315 1559

982

620

500

15

14570 15123 15538 15808 15925 15888 15694 15344 14844 14199 13420 12520 11514 10419 9258 8055 6836 5631 4473 3394 2433 1626 1012

627

500

16

16484 17003 17372 17583 17630 17513 17229 16783 16179 15426 14535 13521 12399 11191 9918 8606 7285 5984 4738 3582 2555 1695 1042

635

500

17

18539 19016 19328 19471 19439 19232 18850 18299 17583 16714 15704 14568 13324 11995 10605 9180 7751 6350 5013 3777 2681 1767 1074

642

500

18

20739 21163 21409 21474 21353 21047 20559 19893 19057 18064 16926 15661 14290 12834 11320 9776 8235 6730 5298 3978 2812 1841 1107

650

500

19

23086 23447 23617 23594 23374 22960 22355 21566 20602 19476 18203 16803 15296 13706 12063 10395 8737 7123 5593 4187 2947 1917 1141

659

500

20

25583 25870 25954 25832 25504 24972 24241 23319 22218 20951 19536 17992 16342 14614 12835 11038 9257 7531 5899 4403 3087 1996 1176

667

500

21

28231 28433 28420 28190 27743 27083 26217 25154 23907 22491 20924 19230 17431 15556 13636 11704 9796 7953 6214 4625 3231 2078 1212

676

500

22

31034 31141 31020 30670 30094 29296 28285 27071 25669 24095 22370 20516 18561 16533 14465 12393 10354 8388 6540 4855 3380 2162 1249

685

500

23

33993 33993 33753 33273 32557 31611 30445 29071 27505 25764 23872 21852 19733 17546 15325 13106 10930 8838 6877 5092 3533 2248 1287

694

500

24

37111 36993 36622 36001 35135 34030 32699 31155 29416 27500 25432 23239 20949 18595 16214 13843 11525 9303 7224 5337 3691 2337 1326

703

500

22

1.7e. Payoff Table 2 (for the Actual Experiment)
Your Investment Number
Your
Payoff

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

0
1
2
Your

3

Opponent's

4

Investment

5

Number

6

1484

2446

3066

3246

2902

2127

1200

581

3245

4512

5057

4921

4109

2821

1460

609

5705

7036

7332

6749

5383

3536

1724

636

9122

10295

10154

8952

6883

4364

2024

667

13575

14338

13553

11545

8620

5310

2364

701

19132

19206

17555

14548

10603

6376

2743

739

25855

24939

22187

17973

12838

7567

3163

781

33800

31573

27472

21836

15336

8887

3626

827

7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

23

1.7f. Payoff Table 3 (for the actual experiment)
Your Investment Number

Your
Opponent's
Investment
Number

24

24

B

B
Instructions

2. Instruction Sheets for Treatment B
2.1. Overview

First, please confirm the following items on your desk.

In each period, you will receive 24 units of money. This money is not real× Overview (this set of papers)

× Experiment Proceduremoney, but please imagine that you have 24 units of money. You can determine the× Participation Cards, Investment Cards (38 sheets in total)

number of units for investment out of 24. One of subjects will be your opponent. An

× Payoff Tables for Practice (3 sheets)

experimenter will choose your opponent from the subjects at random.

× Pencil and eraser

× Record Sheet× Instructions for Payoff Tables

First, you decide whether or not you participate in investment, and record yourdecision on participation in the "Participation Card." Then an experimenter will collectthe "Participation Cards." Your "Participation Card" will be distributed to yourThe "Experiment Procedure" summarizes what subjects should do in theexperiment. Please take a look at it if necessary.

opponent, and your opponent's "Participation Card" will be distributed to you. Bylooking at your opponent's "Participation Card", you can know whether or not yourThe "Record Sheet" is for the record of your information in the experiment. You

opponent participates in investment. If you wrote "Participate" in the "Participation

will record "Your Investment Number," "Your Opponent's Investment Number,"Card," then choose your investment number. Decide how many units of money out of"Your Participation Decision," "Your Opponent's Participation Decision," "Your Payoff,"

24 you invest, and record your investment number in the "Investment Card." Also, if

the "Reason for Your Participation Decision," and the "Reason for Your Decision on

you wrote "Not Participate" in the "Participation Card," then record "Not Participate" inInvestment Number" in the "Record Sheet."the "Investment Card". Then an experimenter will collect the "Investment Cards." Your
"Investment Card" will be distributed to your opponent, and your opponent's"Participation Cards" and "Investment Cards" are bound together: the"Investment Card" will be distributed to you. By looking at your opponent's"Participation Card" for the first period is on the top, the "Investment Card" for that

"Investment Card," you can know your opponent's investment number. Your payoff isperiod is on the next page, and so on. You will write whether or not you participate indetermined by your investment number as well as your opponent's investment number.

investment in the "Participation Card" and will write your investment number in the

You can find how much your payoff is by looking at the "Payoff Table.""Investment Card." In the upper sides of both cards, you will find the sentence "YourThis is one period. Your opponent in the next period is randomly chosen by an

opponent's ID Number is ¨." This is the ID number of your opponent in the present

experimenter, and your opponent changes in each period. This experiment consists of 4

period. In the lower side, you will find the sentence "Your ID number is __." This

periods of practice and then 15 periods of the actual experiment. In the following, theindicates your ID number.

instructions for the experiment are explained in detail. If you follow instructions closely
and make investment decisions carefully, you can receive reasonable earnings. Your

The "Payoff Tables" specify how much your payoff is. There are three kinds ofearnings are determined according to your payoff and will be paid to you after thetables, each one having a different color: "Payoff Table 1", "Payoff Table 2", and "Payoff

experiment. How to compute your earnings will be explained later.

Table 3." Two "Supplement Tables" with the same color are attached to each of these

Please remember that you cannot talk to other subjects from now on. If thishappens, the experiment will be stopped at that point.

"Payoff Tables". The "Supplement Tables" are to help you understand the "Payoff Table."
The same tables are distributed to all subjects. Which payoff table should be used
depends on your participation decision and your opponent's. An experimenter will
explain these tables according to "Instructions for Payoff Tables" later.
The "Payoff Tables" that you have now are for practice. The "Payoff Tables" forthe actual experiment will be distributed to you after the practice periods.

25

26

B

B
Next if the symbol O is in the cell of "Participation in Investment"-"You" in the

Let me explain the detailed procedures of the experiment.

"Record Sheet," then choose an investment number from 0 to 24 by looking at the "Payoff

You will select investments for 4 practice periods and then for 15 actual

Tables" and circle the number that you chose in the "Investment Card." You also record

experiment periods. The units of money you have in the beginning of each period are 24

this number in the cell of "Investment Number"-"You" in the "Record Sheet." If theand they are the same for all subjects. One of the subjects is your opponent. You andsymbol ´ is in the cell of "Participation in Investment"-"You" in the "Record Sheet," thenyour opponent play an investment game. First, you decide whether or not you

circle the word "Not Participate" in the "Investment Card" and leave a blank in the cell ofparticipate in investment by looking at the "Payoff Tables." Then circle either the word

"Investment Number"-"You" in the "Record Sheet." An experimenter collects the"Participate" or the word "Not Participate" in the "Participation Card." Also, write the"Investment Cards." Your "Investment Card" is distributed to your opponent, and yoursymbol O in the cell of "Participation in Investment"-"You" if you chose "Participate,"

opponent's "Investment Card" is distributed to you. While the experimenter collects andand write the symbol ´ in it if you chose "Not Participate." An experimenter collects the

distributes the "Investment Cards," fill in the cell of the "Reason for Your Decision on"Participation Cards." Your "Participation Card" is distributed to your opponent, andYour Investment Number" in the "Record Sheet." Please specify what you expected your

your opponent's "Participation Card" is also distributed to you. In the meantime, please

opponent's investment decision and why you chose your investment number based on

answer the question of the "Reason for Your Decision on Participation" in the "Record

your expectation.

Sheet." Please specify the reason why you chose "Participation" in investment, or why

When your opponent's "Investment Card" has been distributed to you, write your

you chose "Not Participate" in investment in the column of the "Reason for Your

opponent's investment number in the cell of "Investment Number"-"Your Opponents" inDecision on Participation." When you have received your opponent's "Participationthe "Record Sheet." Insert the "Investment Card" into the envelope beside your desk

Card," write the symbol O in the cell of "Participation in Investment"-"Your Opponent"

after writing it. "Your investment number" as well as "Your opponent's investmentin the "Record Sheet" if your opponent chose "Participate," and write the symbol ´ in it if

number" have been recorded in the "Record Sheet." Find "Your Payoff" according to

your opponent chose "Not Participate." Please insert the "Participation Card" into the"Payoff Tables." "Payoff Tables" indicate how much "Your Payoff" is, depending onenvelope beside your desk after you finish writing.

"Your Investment" and "Your Opponent's Investment". The equation for how to

Then you will find the symbol O or ´ in the cells of "Participation in Investment"- "You" and "Participation in Investment" - "Your Opponent" in the "Record Sheet." Thefollowing tables illustrates which "Payoff Table" you should take a look at, depending on
combinations of the symbols O and ´:

opponent

to which you

in investment(write O or ´)

Now let me explain about your earnings. Your earnings depend only on theRed

sum of "Your Payoffs" in the actual experiment, but not on your payoffs in the first 4

Payoff Table 2

Blueperiods of practice. Your earnings are computed in the following way:

Payoff Table 3

Yellow

Payoff Table 1

O

®

O

´

®

´

O

®

´

´

®

500

27

"Instructions for Payoff Tables."payoff tableshould refer
O

This is the end of one period. In the next period, an experimenter chooses your

Next let me explain how to read the payoff tables. Please take a look at the
The payoff table The color of theYour

Participation

Payoff," write it in the cell of "Your Payoff" in the "Record Sheet."
opponent at random. You will face a different opponent in each period.

The record sheet
Youcompute your payoff is described at the end of this overview. After checking "YourYour earnings = (the sum of "Your Payoffs" in the actual experiment) ´ 0.033 yen

28

B

B

For example, suppose that the sum of "Your Payoffs" in the actual experiment is 84,423.
Then your earnings are 2786 yen since 84,423 ´ 0.033 = 2786. Fractions are rounded off

where a denotes your investment number and b stands for your opponent's investment

to the nearest yen.

number.

You will have three minutes for looking at the "Payoff Tables" for practice before
4 periods of practice begin. After the practice periods, put the "Payoff Tables" forpractice into the envelope beside your desk. The "Payoff Tables" for the actual
experiment will be distributed afterward. You will have ten minutes for looking at the"Payoff Tables" for the actual experiment before it starts.
You must understand the procedure of the experiment as well as how to read thepayoff tables completely. If you have any questions, please ask an experimenter.
However, do not talk to other subjects. Please follow experimenters' instructions.
Please see the following equations if you are interested in how to compute yourpayoff.
The equations for computing "Your Payoff":"Your Payoff" depends on your investment number and your opponent's
investment number. In the practice, your payoff is calculated as follows:Your payoff ={(24 - a)0.467 ´ (a + b)1-0.467 }4.4+ 500 ,

50

where a denotes your investment number and b stands for your opponent's investment
number. For example, suppose that "Your Investment Number" is 8 and "Your
Opponent's Investment Number" is 10. Then "Your Payoff" is 5737 sinceYour payoff ={(24 - 8)0.467 ´ (8 + 10)1-0.467 }

4.4

50

+ 500 » 5737 .

Fractions are rounded off to one decimal place for all numerical values in the payoff
tables.
In the actual experiment, your payoff is determined according to thefollowing equation:{(24 - a)0.47 ´ (a + b + 3)1-0.47 }Your payoff =50

29

4 . 45+ 500 ,

30

B
2.2. Experiment ProcedureB· While an experimenter collects and redistributes "Investment Cards", fill out the cell ofthe "Reason for Your Decision on Investment Number" in the "Record Sheet."· When your opponent's "Investment Card" is distributed to you, write your opponent's(1) Instructions for the experiment

investment number in the cell of "Investment Number"-"Your Opponent" in the "Record(2) Practice

Sheet."· An experimenter instructs subjects that "You have 3 minutes to look at payoff tables."· Put the "Investment Card" into the envelope beside your desk.

· After 3 minutes, an experimenter instructs subjects that "You will select investments· Find your payoff by looking at the "Payoff Table" and write it in the cell of "Yourfor 4 practice periods. Let us start the first period".

Payoff" in the "Record Sheet."· Decide whether or not you participate in investment and circle either the word

· An experimenter instructs subjects that "Let us start the second period for practice.""Participate" or the word "Not Participate" in the "Investment Card."* Practice consists of 4 periods. The above procedure is repeated 4 times.

· If you have chosen "Participate", write the symbol O in the cell of "Participation in* After practice, an experimenter instructs subjects that "Please put the "Payoff Tables"

Investment"-"You" in the "Record Sheet." If you have chosen "Not Participate", write thefor practice into the envelope beside your desk."

symbol ´ in that cell.
· Take off the top sheet of the bunched "Participation Cards" and put it up-side-down on

An experimenter distributes "Payoff Tables" for the actual experiment.

your table.
· While an experimenter collects and redistributes "Participation Cards," fill out the cell(3) The actual experimentof the "Reason for Your Decision on Participation" in the "Record Sheet."· An experimenter instructs subjects that "You have 10 minutes to look at payoff tables."· When your opponent's "Participation Card" is distributed to you, check which word is· After 10 minutes, an experimenter instructs subjects that "You will select investments

circled, "Participate" or "Not Participate." If your opponent has chosen "Participate",for 15 actual experiment periods. Let us start the first period of the actual experiment."

write the symbol O in the cell of "Participation in Investment"-"Your Opponent" in the· Decide whether or not you participate in investment and circle either the word

"Record Sheet." If your opponent has chosen "Not Participate", write the symbol ´ in"Participate" or the word "Not Participate" in the "Investment Card."

that cell.

· If you have chosen "Participate", write the symbol O in the cell of "Participation in· Put the "Participation Card" into the envelope beside your desk.

Investment"-"You" in the "Record Sheet." If you have chosen "Not Participate", write the· Check the combination of the symbols O and ´ in two cells of "Participation insymbol ´ in that cell.

Investment"-"You" and "Participation in Investment"-"Your Opponent" in the "Record· Take off the top sheet of the bunched "Participation Cards" and put it up-side-down on

Sheet" and choose "Payoff Table" you should look at.

your table.

· Decide your investment number based on the "Payoff Table" you have chosen.

· While an experimenter collects and redistributes "Participation Cards," fill out the cell

· If you have selected "Participate" in investment, circle the number that you haveof the "Reason for Your Decision on Participation" in the "Record Sheet."chosen in the "Investment Card." If you have selected "Not Participate" in investment,· When your opponent's "Participation Card" is distributed to you, check which word iscircle the word "Not Participate" in the "Investment Card."

circled, "Participate" or "Not Participate." If your opponent has chosen "Participate",· Write the circled number in the "Investment Card" into the cell of "Investment

write the symbol O in the cell of "Participation in Investment"-"Your Opponent" in the

Number"-"You" in the "Record Sheet." Do not write anything in that cell if you have

"Record Sheet." If your opponent has chosen "Not Participate", write the symbol ´ incircled the word "Not Participate" in the "Investment Card."

that cell.

· Take off the top sheet of the bunched "Investment Cards" and put it up-side-down on· Put the "Participation Card" into the envelope beside your desk.

your table.

31

32

B
· Check the combination of the symbols O and ´ in two cells of "Participation inB
2.3. Instructions for Payoff Tables

Investment"-"You" and "Participation in Investment"-"Your Opponent" in the "Record
Sheet" and choose "Payoff Table" you should look at.

There are three kinds of payoffs tables. Two "Supplemental Payoff Tables" are· Decide your investment number based on the "Payoff Table" you have chosen.

attached with each payoff table. The same three kinds of tables are distributed to all· If you have selected "Participate" in investment, circle the number that you havesubjects. "Your Payoff" in the experiment is determined by "Payoff Tables."chosen in the "Investment Card." If you have selected "Not Participate" in investment,"Supplemental Payoff Tables " are to help your understanding of "Payoff Tables."circle the word "Not Participate" in the "Investment Card."· Write the circled number in the "Investment Card" into the cell of "Investment(1) Instructions for "Payoff Table 1," "Supplemental Payoff Table 1-1," and "Supplemental

Number"-"You" in the "Record Sheet." Do not write anything in that cell if you have

Payoff Table 1-2."

circled the word "Not Participate" in the "Investment Card."

Please take a look at "Payoff Table 1" if the symbol O is written both in the cell of· Take off the top sheet of the bunched "Investment Cards" and put it up-side-down on"Participation in Investment"-"You" and in the cell of "Participation in Investment"-"Youryour table.

Opponent" in the "Record Sheet." "Payoff Table 1" specifies how much "Your Payoff" is,· While an experimenter collects and redistributes "Investment Cards", fill out the cell ofdepending on "Your Investment Number" and "Your Opponent's Investment Number."the "Reason for Your Decision on Investment Number" in the "Record Sheet."

In this table, the column denotes "Your Investment Number" and the row denotes "Your· When your opponent's "Investment Card" is distributed to you, write your opponent's

Opponent's Investment Number." For example, if "Your Investment Number" is 5 andinvestment number in the cell of "Investment Number"-"Your Opponent" in the "Record"Your Opponent's Investment Number" is 3, "Your Payoff" is the number in the cell of

Sheet."

column 5-row 3, that is, 1,613.

· Put the "Investment Card" into the envelope beside your desk.
· Find your payoff by looking at the "Payoff Table" and write it in the cell of "YourPayoff Table 1 (for practice) O O

Payoff" in the "Record Sheet."Your Investment Number· An experimenter instructs subjects that "Let us start the second period of the actual
experiment."* The actual experiment consists of 15 periods. The above procedure is repeated 15
times.
* Please follow experimenter's instructions after the fifteenth period.
(4) After the experiment· Experimenters collect the "Record Sheets."· Experimenters distribute the "Personal Information Sheet and Receipt" and the sheet of"Questionnaires on the Experiment." Please fill out your name, address, and etc. in the"Personal Information Sheet and Receipt." Also, please answer questions in the sheet of"Questionnaires on the Experiment."· The earnings are paid one by one. Please wait until your name is called.
· After receiving your earnings, please fill out the receipt.

0

1

2

3

4

0

500

513

558

637

Opponent's

1

514

564

651

Investment

2

570

665

796

Number

3

680

824

1000

Your

5

6

743

870

1007

769

911

1067

1228

954

1130

1314

1496

1196

1404

1613

1813

Next let me explain how to see "Supplemental Payoff Table 1-1.""Supplemental Payoff Table 1-1" is a rough version of "Payoff Table 1." In thistable, the column denotes "Your Investment Number" and the row denotes "Your
Opponent's Investment Number," as in "Payoff Table 1." However, the number in a cellof this table is the average values of the numbers in the corresponding cells of "Payoff
Table 1." For example, consider the case in which "Your Investment Numbers" are from4 to 6 and "Your Opponent's Investment Numbers" are from 0 to 3. Please see the above"Payoff Table 1." There are three "Your Investment Numbers," 4, 5, and 6, in "Payoff
Table 1." On the other hand, there are four "Your Opponent's Investment Numbers," 0,

33

34

B
1, 2, 3. Therefore, in total, there are 3 ´ 4 = 12 numbers in "Payoff Table 1." Next please

B
Supplemental Payoff Table 1-2 (for Practice) O O

see the following "Supplemental Payoff Table 1-1." The number in the shaded cell of"Supplemental Payoff Table 1-1" is 1,216. This is the average value of 12 numbers in theYour Investment Number

corresponding cells of "Payoff Table 1."
Supplemental Payoff Table 1-1 (for Practice) O O
Your Investment Number
0

1

2

3

4

5

6

0
Your

1

Opponent's

2

Investment

3

Number

4
5

712

1216

1500

2390

Your
Opponent’s
Investment
Number6
Next let me explain the meaning of the symbol "<" in this table. This symbol
indicates which numbers in the neighbor are larger. A number in the open side of thesymbol is larger than a number in the other side. For example, let us compare 712 and
1,216 in "Supplemental Payoff Table 1-1". Since 712 is smaller than 1,216, 1216 is locatedin the open side of the symbol. Also, since 1,216 is smaller than 2309, 2309 is located in
the open side of the symbol.
Let me explain "Supplemental Payoff Table 1-2."
In "Supplemental Payoff Table 1-2," the horizontal axis denotes "Your Investment
Number" and the vertical axis denotes "Your Opponent's Investment Number." Payofflevels are represented by contours in this table. Payoff levels increase in the south-west
direction. For example, consider the case in which "Your Investment Number" is 10 and"Your Opponent's Investment Number" is 6. In the following table, draw a vertical line
down from "Your Investment Number" 10 and a horizontal line from "Your Opponent's
Investment Number" 6 to the right. The intersection of these two lines denotes "YourPayoff." This intersection lies between the contour 3,000 and the contour 4,000. Thismeans that your payoff is a value between 3,000 and 4,000. You will find that yourpayoff is 3,520 by looking at "Payoff Table 1."35(2) Instructions for "Payoff Table 2," "Supplemental Payoff Table 2-1," and"Supplemental Payoff Table 2-2."
Please use "Payoff Table 2" if the symbol O is written in the cell of "Participationin Investment"-"You" and the symbol ´ is in the cell of "Participation in Investment""Your Opponent" in the "Record Sheet." The way of seeing this table is the same as for"Payoff Table 1." But only you make an investment decision since your opponent does
not participate in investment. Thus this table is the same as the first row of "Payoff
Table 1" (the rectangular area with bold outlines in the following table) for the case inwhich your opponent's investment number is 0.

36

B

B

Payoff Table 1 (for Practice) O O
Your Investment Number
9
10 11 12 13 14

0

1

2

3

4

5

6

7

8

500

513

558

637

743

870

1007

1148

1282

1403

1503

1577

1621

1631

1606

1547

1456

1338

1198

1045

888

741

617

531

500

514

564

651

769

911

1067

1228

1386

1531

1656

1754

1821

1852

1845

1800

1718

15

1602

16

1458

17

1292

18

1114

19

936

20

769

21

630

22

535

23

500

24

570

665

796

954

1130

1314

1496

1667

1820

1945

2038

2094

2109

2081

2013

1904

1761

1588

1394

1189

986

798

643

538

500

680

824

1000

1196

1404

1613

1813

1995

2150

2272

2356

2396

2391

2340

2244

2106

1931

1727

1502

1268

1039

830

658

542

500

854

1047

1266

1500

1737

1967

2181

2369

2524

2638

2708

2729

2700

2621

2494

2323

2114

1875

1617

1353

1096

863

673

545

500

1097

1340

1600

1867

2130

2379

2602

2792

2942

3044

3096

3093

3036

2925

2763

2556

2310

2034

1740

1442

1156

898

689

550

500

1416

1705

2004

2302

2587

2849

3078

3266

3405

3491

3520

3490

3400

3253

3053

2805

2518

2202

1870

1537

1219

935

706

554

500

1815

2148

2483

2807

3110

3381

3610

3790

3915

3980

3981

3918

3792

3605

3362

3071

2740

2381

2008

1637

1285

973

723

558

500

2299

2673

3039

3385

3701

3976

4201

4368

4473

4512

4481

4381

4213

3981

3692

3353

2975

2570

2153

1742

1355

1014

742

563

500

2871

3282

3675

4039

4362

4635

4850

5000

5080

5087

5019

4877

4663

4383

4043

3653

3224

2770

2306

1853

1428

1057

761

568

500

3536

3978

4393

4769

5095

5362

5561

5688

5737

5707

5596

5407

5143

4809

4415

3969

3486

2980

2467

1969

1505

1101

781

573

500

4296

4766

5197

5580

5902

6156

6335

6432

6446

6373

6214

5973

5653

5262

4808

4304

3762

3200

2636

2090

1586

1148

803

578

500

5156

5647

6089

6472

6785

7020

7172

7234

7206

7085

6873

6574

6194

5740

5223

4656

4053

3432

2813

2217

1670

1196

824

584

500

6117

6624

7071

7447

7745

7956

8074

8095

8018

7844

7573

7212

6766

6245

5660

5026

4358

3675

2998

2350

1757

1247

847

589

500

7183

7699

8144

8509

8784

8963

9042

9016

8885

8651

8316

7886

7370

6777

6120

5414

4677

3928

3191

2488

1848

1299

871

595

500

8357

8875

9312

9658

9904 10045 10077 9997

9806

9506

9101

8598

8005

7335

6602

5820

5011

4193

3392

2633

1943

1354

896

601

500

9641 10155 10576 10896 11106 11202 11181 11041 10783 10411 9930

9347

8673

7922

7107

6246

5359

4470

3602

2783

2042

1410

921

608

500

11037 11540 11939 12225 12392 12436 12355 12147 11816 11366 10802 10135 9375

8536

7635

6690

5723

4758

3820

2938

2144

1469

948

614

500

12549 13033 13401 13646 13763 13748 13599 13318 12907 12371 11719 10961 10109 9178

8186

7153

6102

5057

4047

3100

2250

1530

975

621

500

14178 14635 14965 15161 15220 15138 14915 14552 14055 13428 12682 11827 10877 9849

8761

7636

6496

5368

4282

3268

2360

1593

1003

628

500

15926 16348 16632 16772 16765 16609 16304 15853 15262 14537 13690 12732 11679 10549 9360

8138

17796 18175 18405 18480 18399 18161 17766 17220 16528 15699 14744 13678 12516 11277 9984

6905

5691

4526

3442

2474

1658

1033

635

500

8659

7330

6026

4779

3622

2591

1725

1063

643

500

19790 20117 20284 20287 20124 19795 19304 18654 17854 16914 15845 14664 13387 12035 10631 9201

7771

6374

5041

3808

2713

1795

1094

651

500

21910 22176 22272 22193 21940 21513 20916 20156 19241 18182 16993 15691 14294 12823 11304 9762

8228

6733

5311

4000

2839

1867

1126

659

500

24157 24354 24369 24201 23849 23315 22606 21727 20690 19506 18190 16760 15236 13641 12001 10344 8701

7104

5591

4199

2968

1941

1159

667

500

1800
1600
1400
1200
Your Payoff

0
1
2
Your
3
Opponent's 4
Investment 5
6
Number
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

Supplemental Payoff Table 2-2 (for Practice) O ´

1000
800
600
400
200
0
0

1

2

3

4

5

6

7

8

9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Your Investment Number

Instructions for "Supplemental Payoff Table 2-1" are the same as for"Supplemental Payoff Table 1-1."
In "Supplemental Payoff Table 2-2", the horizontal axis stands for "YourInvestment Number" and the vertical axis denotes "Your Payoff." This table illustrates
how much "Your Payoff" is, depending on "Your Investment Number."(3) Instructions for "Payoff Table 3," "Supplemental Payoff Table 3-1," and "Supplemental
Payoff Table 3-2."
Please use "Payoff Table 3" if the symbol ´ is written in the cell of "Participationin Investment"-"You" and the symbol O is in the cell of "Participation in Investment""Your Opponent" in the "Record Sheet." The way of seeing this table is the same as for"Payoff Table 1." But only your opponent makes an investment decision since you do
not participate in investment. This table is the same as the first column of "Payoff Table
1" (the rectangular area with bold outlines in the following table) for the case in whichyour investment number is 0.

37

38

B

B

Payoff Table 1 (for Practice) O O
Supplemental Payoff Table 3-2 (for Practice) ´ O
0
1
2
Your
3
Opponent's 4
Investment 5
6
Number
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

1

2

3

4

5

6

7

8

Your Investment Number
9
10 11 12 13 14

15

16

17

18

19

20

21

22

23

24

500

513

558

637

743

870

1007

1148

1282

1403

1503

1577

1621

1631

1606

1547

1456

1338

1198

1045

888

741

617

531

500

514

564

651

769

911

1067

1228

1386

1531

1656

1754

1821

1852

1845

1800

1718

1602

1458

1292

1114

936

769

630

535

500

570

665

796

954

1130

1314

1496

1667

1820

1945

2038

2094

2109

2081

2013

1904

1761

1588

1394

1189

986

798

643

538

500

680

824

1000

1196

1404

1613

1813

1995

2150

2272

2356

2396

2391

2340

2244

2106

1931

1727

1502

1268

1039

830

658

542

500

854

1047

1266

1500

1737

1967

2181

2369

2524

2638

2708

2729

2700

2621

2494

2323

2114

1875

1617

1353

1096

863

673

545

500

1097

1340

1600

1867

2130

2379

2602

2792

2942

3044

3096

3093

3036

2925

2763

2556

2310

2034

1740

1442

1156

898

689

550

500

1416

1705

2004

2302

2587

2849

3078

3266

3405

3491

3520

3490

3400

3253

3053

2805

2518

2202

1870

1537

1219

935

706

554

500

1815

2148

2483

2807

3110

3381

3610

3790

3915

3980

3981

3918

3792

3605

3362

3071

2740

2381

2008

1637

1285

973

723

558

500

2299

2673

3039

3385

3701

3976

4201

4368

4473

4512

4481

4381

4213

3981

3692

3353

2975

2570

2153

1742

1355

1014

742

563

500

2871

3282

3675

4039

4362

4635

4850

5000

5080

5087

5019

4877

4663

4383

4043

3653

3224

2770

2306

1853

1428

1057

761

568

500

3536

3978

4393

4769

5095

5362

5561

5688

5737

5707

5596

5407

5143

4809

4415

3969

3486

2980

2467

1969

1505

1101

781

573

500

4296

4766

5197

5580

5902

6156

6335

6432

6446

6373

6214

5973

5653

5262

4808

4304

3762

3200

2636

2090

1586

1148

803

578

500

5156

5647

6089

6472

6785

7020

7172

7234

7206

7085

6873

6574

6194

5740

5223

4656

4053

3432

2813

2217

1670

1196

824

584

500

6117

6624

7071

7447

7745

7956

8074

8095

8018

7844

7573

7212

6766

6245

5660

5026

4358

3675

2998

2350

1757

1247

847

589

500

7183

7699

8144

8509

8784

8963

9042

9016

8885

8651

8316

7886

7370

6777

6120

5414

4677

3928

3191

2488

1848

1299

871

595

500

8357

8875

9312

9658

9904 10045 10077 9997

9806

9506

9101

8598

8005

7335

6602

5820

5011

4193

3392

2633

1943

1354

896

601

500

9641 10155 10576 10896 11106 11202 11181 11041 10783 10411 9930

9347

8673

7922

7107

6246

5359

4470

3602

2783

2042

1410

921

608

500

11037 11540 11939 12225 12392 12436 12355 12147 11816 11366 10802 10135 9375

8536

7635

6690

5723

4758

3820

2938

2144

1469

948

614

500

12549 13033 13401 13646 13763 13748 13599 13318 12907 12371 11719 10961 10109 9178

8186

7153

6102

5057

4047

3100

2250

1530

975

621

500

14178 14635 14965 15161 15220 15138 14915 14552 14055 13428 12682 11827 10877 9849

8761

7636

6496

5368

4282

3268

2360

1593

1003

628

500

15926 16348 16632 16772 16765 16609 16304 15853 15262 14537 13690 12732 11679 10549 9360

8138

17796 18175 18405 18480 18399 18161 17766 17220 16528 15699 14744 13678 12516 11277 9984

6905

5691

4526

3442

2474

1658

1033

635

7330

6026

4779

3622

2591

1725

1063

643

500

7771

6374

5041

3808

2713

1795

1094

651

500

21910 22176 22272 22193 21940 21513 20916 20156 19241 18182 16993 15691 14294 12823 11304 9762

8228

6733

5311

4000

2839

1867

1126

659

500

24157 24354 24369 24201 23849 23315 22606 21727 20690 19506 18190 16760 15236 13641 12001 10344 8701

7104

5591

4199

2968

1941

1159

667

500

"Supplemental Payoff Table 1-1."

20000

15000

10000

5000

500

8659

19790 20117 20284 20287 20124 19795 19304 18654 17854 16914 15845 14664 13387 12035 10631 9201

Instructions for "Supplemental Payoff Table 3-1" are the same as for

25000

Your Payoff

0

0
0

1

2

3

4

5

6

7

8

9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Your Opponent's Investment Number

Finally let us consider the case in which the symbol ´ is in both the cell of"Participation in Investment"-"You" and the cell of "Participation in Investment-"Your
Opponent." In this case, neither you nor your opponent can make an investment since

In "Supplemental Payoff Table 3-2", the horizontal axis stands for "Your
Opponent's Investment Number" and the vertical axis denotes "Your Payoff." This tableillustrates how much "Your Payoff" is, depending on "Your Opponent's Investment
Number."both choose "Nor Participate" in investment. Therefore your payoff is 500, the numberin the cell in which both "Your Investment Number" and "Your Opponent's Investment
Number" are 0. In the actual experiment, this value is 706.
This is the end of instructions for payoff tables.

39

40

B
2.4. Participation Card

The Actual ExperimentYour opponent's ID number is

Period 1

Do you participate in investment? Please circle one of thefollowing:B

2.6. Record Sheet

Practice 1 (White "Participation Card" and White "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate ininvestment or why you do not participate).
OpponentO O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
500
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24· Participate· Not Participate
Your ID number is _____.

2.5. Investment Card

The Actual ExperimentYour opponent's ID number is

Period 1

Please circle your investment number. (please circle "Not
Participate" if you do not participate in investment.)
Not Participate
0
14

1

2
15

3

4

5

16

17

18

6

7
19

8

9

10

11

12

20

21

22

23

24

Your ID number is _____.

13

Practice 2 (Red "Participation Card" and Red "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
ParticipaO O Payoff Table 1 (Red)tion in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
500
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in theYour Payoff
opponent's investment number and the reason
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24

Practice 3 (Blue "Participation Card" and Blue "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
ParticipaO O Payoff Table 1 (Red)tion in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
500
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24

41

42

B

B

Practice 4 (Yellow "Participation Card" and Yellow "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
ParticipaO O Payoff Table 1 (Red)tion in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
500
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Period 3 of the Actual Experiment (Blue "Participation Card" and Blue "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
ParticipaO O Payoff Table 1 (Red)tion in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24

Investment
Number0 ~ 24* Please note that in the actual experiment, your payoff is 706 when ´ is in both the cell of "Participation in
Investment"-"You" and the cell of "Participation in Investment"-"Your Opponent."
Period 1 of the Actual Experiment (White "Participation Card" and White "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
O O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24

Period 2 of the Actual Experiment (Red "Participation Card" and Red "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
O O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 2443

Period 4 of the Actual Experiment (Yellow "Participation Card" and Yellow "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
O O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24

Period 5 of the Actual Experiment (White "Participation Card" and White "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
O O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 2444

B

Period 6 of the Actual Experiment (Red "Participation Card" and Red "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
ParticipaO O Payoff Table 1 (Red)tion in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24B
Period 9 of the Actual Experiment (White "Participation Card" and White "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
ParticipaO O Payoff Table 1 (Red)tion in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in theYour Payoff
opponent's investment number and the reason
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24

Period 7 of the Actual Experiment (Blue "Participation Card" and Blue "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
O O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24

Period 8 of the Actual Experiment (Yellow "Participation Card" and Yellow "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
O O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 2445

Period 10 of the Actual Experiment (Red "Participation Card" and Red "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
ParticipaO O Payoff Table 1 (Red)tion in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24

Period 11 of the Actual Experiment (Blue "Participation Card" and Blue "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
O O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 2446

B

B

Period 12 of the Actual Experiment (Yellow "Participation Card" and Yellow "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
ParticipaO O Payoff Table 1 (Red)tion in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Period 15 of the Actual Experiment (Blue "Participation Card" and Blue "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
ParticipaO O Payoff Table 1 (Red)tion in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24

Investment
Number0 ~ 24

Period 13 of the Actual Experiment (White "Participation Card" and White "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
O O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 24Your ID Number is

Period 14 of the Actual Experiment (Red "Participation Card" and Red "Investment Card")
The Reason for Your Decision on Participation
You
Your
Payoff Table (color)(please specify the reason why you participate in
Opponent
investment or why you do not participate).
O O Payoff Table 1 (Red)Participation in® O ´ Payoff Table 2 (Blue)
investment´ O Payoff Table 3 (Yellow)(write O or
´ ´
706
´)
¯
¯
The Reason for Your Decision on Investment
Fill out if Fill out if
Number (Please specify your expectation on yourO is in the O is in the
opponent's investment number and the reason
Your Payoff
above cell above cell
why you chose your investment number.)¯¯Investment
Number0 ~ 2447

48

B
2.7. Questionnaires on the ExperimentB(4) This question is to ask your behavior in the actual experiment. Which of thefollowing is closest to your way of thinking on participation and investment

ID Numberdecisions? Choose one of the following.
1. It is desirable that my payoff is as high, regardless of my opponent's

Please answer the following questions.

payoff.

(1) Did you understand the rules of the experiment? Please circle one of the numbers

absolute value of my payoff, even when the difference between my payoff and myof the following answers. If you choose 2, circle either "Practice" or "Actual

opponent's is small.

2. If my payoff is higher than my opponent's payoff, I do not care about theExperiment" and write the number of period from which you have understood the

3. It is desirable that both my payoff and my opponent's payoff are as high as
possible.

rules.

4. If I can make my opponent's payoff as small as possible, it is fine that my
1. I have understood the rules from the beginning of the experiment.
2. I have understood the rules from a middle of the experiment:
From period () in Practice ž Actual Experiment

payoff is moderate.
5. If my payoff is the same as my opponent's payoff, I do not care about theabsolute value of my payoff.
6. Others (please specify).

3. I could not understand the rules.
(2) Did you understand the three kinds of payoff tables? Please circle one of thenumbers of the following answers. If you choose 2, write the numbers of the payoff(5) This is to ask about your participation behavior in the actual experiment. How

tables that you could not understand.

often did you participate in investment? Please choose one of the following andwrite the reasons for your decisions on participation as concretely as possible.

1. I understood all three tables.
2. I could not understand payoff table ().

1. I always participated in investment.
2. I never participated in investment.

(3) Did you notice anything about the three kinds of payoff tables? Which tables did

3. I did not participate in investment several times, but the number ofyou take a look at when you decided your investment number? Please answer these

periods at which I participated in investment was greater than the number ofquestions concretely as much as you can.

periods at which I did not.
4. I participated in investment several times, but the number of periods at
which I did not participate in investment was greater than the number of periods at
which I did.
The reasons for your decisions on participation:

49

50

B

B

(6) How did you choose your investment number when you participated ininvestment? Please answer the question both in the case in which your opponent
participated in investment and the case in which your opponent did not.
When your opponent participated in investment:

When your opponent did not participate in investment:(7) Finally, what would be the best choice for your participation and investment?
What do you think from your experience in the experiment? Why? Please answer
these questions as concretely as you can.

Please confirm that your ID number is filled in again.
Thank you very much.

51

52

2.8a. Payoff Table 1 (for Practice)○○Your Investment Number
Your
Payoff

0

1

2

3

4

5

0

500

513

558

637

743

1

514

564

651

769

Your

2

570

665

796

954 1130 1314 1496 1667 1820 1945 2038 2094 2109 2081 2013 1904 1761 1588 1394 1189

Opponent's

3

680

Investment

4

Number

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

870 1007 1148 1282 1403 1503 1577 1621 1631 1606 1547 1456 1338 1198 1045

888

741

617

531

500

911 1067 1228 1386 1531 1656 1754 1821 1852 1845 1800 1718 1602 1458 1292 1114

936

769

630

535

500

986

798

643

538

500

824 1000 1196 1404 1613 1813 1995 2150 2272 2356 2396 2391 2340 2244 2106 1931 1727 1502 1268 1039

830

658

542

500

854 1047 1266 1500 1737 1967 2181 2369 2524 2638 2708 2729 2700 2621 2494 2323 2114 1875 1617 1353 1096

863

673

545

500

1097 1340 1600 1867 2130 2379 2602 2792 2942 3044 3096 3093 3036 2925 2763 2556 2310 2034 1740 1442 1156

898

689

550

500

6

1416 1705 2004 2302 2587 2849 3078 3266 3405 3491 3520 3490 3400 3253 3053 2805 2518 2202 1870 1537 1219

935

706

554

500

7

1815 2148 2483 2807 3110 3381 3610 3790 3915 3980 3981 3918 3792 3605 3362 3071 2740 2381 2008 1637 1285

973

723

558

500

8

2299 2673 3039 3385 3701 3976 4201 4368 4473 4512 4481 4381 4213 3981 3692 3353 2975 2570 2153 1742 1355 1014

742

563

500

9

2871 3282 3675 4039 4362 4635 4850 5000 5080 5087 5019 4877 4663 4383 4043 3653 3224 2770 2306 1853 1428 1057

761

568

500

10

3536 3978 4393 4769 5095 5362 5561 5688 5737 5707 5596 5407 5143 4809 4415 3969 3486 2980 2467 1969 1505 1101

781

573

500

11

4296 4766 5197 5580 5902 6156 6335 6432 6446 6373 6214 5973 5653 5262 4808 4304 3762 3200 2636 2090 1586 1148

803

578

500

12

5156 5647 6089 6472 6785 7020 7172 7234 7206 7085 6873 6574 6194 5740 5223 4656 4053 3432 2813 2217 1670 1196

824

584

500

13

6117 6624 7071 7447 7745 7956 8074 8095 8018 7844 7573 7212 6766 6245 5660 5026 4358 3675 2998 2350 1757 1247

847

589

500

14

7183 7699 8144 8509 8784 8963 9042 9016 8885 8651 8316 7886 7370 6777 6120 5414 4677 3928 3191 2488 1848 1299

871

595

500

15

8357 8875 9312 9658 9904 10045 10077 9997 9806 9506 9101 8598 8005 7335 6602 5820 5011 4193 3392 2633 1943 1354

896

601

500

16

9641 10155 10576 10896 11106 11202 11181 11041 10783 10411 9930 9347 8673 7922 7107 6246 5359 4470 3602 2783 2042 1410

921

608

500

17

11037 11540 11939 12225 12392 12436 12355 12147 11816 11366 10802 10135 9375 8536 7635 6690 5723 4758 3820 2938 2144 1469

948

614

500

18

12549 13033 13401 13646 13763 13748 13599 13318 12907 12371 11719 10961 10109 9178 8186 7153 6102 5057 4047 3100 2250 1530

975

621

500

19

14178 14635 14965 15161 15220 15138 14915 14552 14055 13428 12682 11827 10877 9849 8761 7636 6496 5368 4282 3268 2360 1593 1003

628

500

20

15926 16348 16632 16772 16765 16609 16304 15853 15262 14537 13690 12732 11679 10549 9360 8138 6905 5691 4526 3442 2474 1658 1033

635

500

21

17796 18175 18405 18480 18399 18161 17766 17220 16528 15699 14744 13678 12516 11277 9984 8659 7330 6026 4779 3622 2591 1725 1063

643

500

22

19790 20117 20284 20287 20124 19795 19304 18654 17854 16914 15845 14664 13387 12035 10631 9201 7771 6374 5041 3808 2713 1795 1094

651

500

23

21910 22176 22272 22193 21940 21513 20916 20156 19241 18182 16993 15691 14294 12823 11304 9762 8228 6733 5311 4000 2839 1867 1126

659

500

24

24157 24354 24369 24201 23849 23315 22606 21727 20690 19506 18190 16760 15236 13641 12001 10344 8701 7104 5591 4199 2968 1941 1159

667

500

23

24

53

2.8b. Supplemental Payoff Table 1-1 (for Practice)○○Your Investment Number
Your
Payoff

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

0
1
2
Your

3

Opponent's

4

Investment

5

Number

6

712

1216

1688

1959

1903

1521

967

558

1500

2390

2941

3086

2755

2031

1166

580

2876

3981

4467

4369

3683

2570

1372

602

4990

6154

6434

5959

4798

3203

1609

627

7916

8954

8869

7870

6111

3936

1880

656

11720

12420

11796

10117

7628

4771

2185

687

16456

16586

15237

12714

9357

5712

2526

723

22176

21485

19214

15673

11305

6762

2903

762

7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

54

2.8c. Supplemental Payoff Table 1-2 (for practice) O O
Your Investment Number

Your
Opponent's
Investment
Number55

2.8d. Payoff Table 2 (for Practice)○×Your Investment Number

Your
Payoff

0

1

2

3

4

5

6

7

8

9

10

11

12

500

513

558

637

743

870 1007 1148 1282 1403 1503 1577 1621 1631 1606 1547 1456 1338 1198 1045

56

13

14

15

16

17

18

19

20

21

22

23

24

888

741

617

531

500

2.8e. Supplemental Payoff Table 2-1 (for Practice)

○

×

14

15

Your Investment Number

0

1

2

Your
Payoff

3

4

552

5

6

7

873

8

9

10

11

1277

12

13

1567

16

1595

17

18

19

1331

20

21

22

891

549

57

2.8f. Supplemental Payoff Table 2-2 (for Practice) ○×

1800

1600

1400

Your Payoff

1200

1000

800

600

400

200

0
0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Your Investment Number

58

15

16

17

18

19

20

21

22

23

23

24

24

2.8g. Payoff Table 3 (for Practice)×○Your Payoff

0

500

1

514

Your

2

570

Opponent's

3

680

Investment

4854

Number

5

1097

6

1416

7

1815

8

2299

9

2871

10

3536

11

4296

12

5156

13

6117

14

7183

15

8357

16

9641

17

11037

18

12549

19

14178

20

15926

21

17796

22

19790

23

21910

24

24157

59

2.8h. Supplemental Payoff Table 3-1 (for Practice)×Your Payoff

0
Your

1

Opponent's

2

Investment

3

Number

4
5

566

1123

6
7
8

2328

9
10
11

4329

12
13
14

7219

15
16
17

11076

18
19
20

15967

21
22
23

21952

24

60

○

300002.8i. Supplemental Payoff Table 3-2 (for Practice) ×○25000

Your Payoff

20000

15000

10000

5000

0
0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

14

15

16

18

19

20

21

22

23

24

Your Opponent's Investment Number

61

2.8j. Payoff Table 1 (for the Actual Experiment)○○

Your Investment Number
Your
Payoff

0

1

0

706

1
2

2

3

4

5

6

7

8

9

10

11

12

13

17

18

19

20

21

22

23

24

871 1072 1297 1536 1775 2003 2210 2386 2523 2615 2658 2648 2585 2470 2309 2106 1871 1614 1349 1091

858

669

543

500

905 1127 1379 1647 1919 2183 2427 2641 2816 2944 3019 3039 3001 2905 2755 2555 2313 2038 1743 1443 1154

894

685

548

500

1186 1465 1764 2072 2374 2658 2913 3129 3297 3411 3465 3456 3385 3252 3061 2819 2534 2217 1881 1543 1220

933

703

552

500

3

1554 1888 2232 2575 2902 3202 3463 3675 3831 3925 3952 3911 3801 3626 3391 3102 2770 2406 2027 1648 1290

973

721

556

500

Your

4

2017 2401 2787 3160 3508 3817 4078 4281 4420 4488 4483 4403 4250 4028 3743 3404 3020 2608 2181 1759 1363 1015

740

561

500

Opponent's

52578 3010 3432 3831 4193 4507 4762 4950 5064 5101 5057 4934 4733 4459 4119 3725 3287 2821 2344 1877 1441 1060

760

566

500

Investment

63244 3718 4171 4590 4960 5272 5515 5681 5766 5765 5677 5504 5249 4918 4519 4065 3568 3045 2516 2000 1522 1106

781

571

500

Number74018 4529 5008 5440 5812 6115 6339 6478 6526 6481 6343 6114 5800 5406 4944 4425 3866 3282 2696 2129 1607 1155

802

576

500

8

4904 5447 5944 6383 6751 7038 7237 7340 7345 7250 7056 6765 6385 5924 5393 4806 4179 3532 2886 2265 1696 1206

825

582

500

9

5907 6475 6984 7422 7779 8043 8209 8271 8225 8073 7816 7458 7007 6472 5867 5207 4508 3793 3084 2407 1789 1259

849

588

500

10

7031 7616 8130 8561 8897 9132 9257 9270 9168 8951 8624 8193 7664 7051 6367 5628 4854 4067 3292 2555 1886 1315

874

594

500

11

8278 8873 9384 9800 10109 10306 10384 10339 10173 9886 9482 8970 8359 7661 6892 6070 5217 4354 3509 2710 1987 1372

899

600

500

12

9653 10250 10750 11142 11416 11567 11589 11480 11242 10877 10390 9791 9090 8302 7444 6534 5596 4654 3736 2871 2092 1432

926

606

500

13

11158 11749 12229 12589 12820 12916 12875 12694 12376 11925 11349 10656 9860 8976 8022 7019 5992 4967 3972 3039 2201 1494

953

613

500

14

12796 13372 13824 14144 14323 14356 14243 13982 13576 13033 12358 11565 10667 9681 8627 7526 6406 5292 4217 3213 2315 1559

982

620

500

15

14570 15123 15538 15808 15925 15888 15694 15344 14844 14199 13420 12520 11514 10419 9258 8055 6836 5631 4473 3394 2433 1626 1012

627

500

16

16484 17003 17372 17583 17630 17513 17229 16783 16179 15426 14535 13521 12399 11191 9918 8606 7285 5984 4738 3582 2555 1695 1042

635

500

17

18539 19016 19328 19471 19439 19232 18850 18299 17583 16714 15704 14568 13324 11995 10605 9180 7751 6350 5013 3777 2681 1767 1074

642

500

18

20739 21163 21409 21474 21353 21047 20559 19893 19057 18064 16926 15661 14290 12834 11320 9776 8235 6730 5298 3978 2812 1841 1107

650

500

19

23086 23447 23617 23594 23374 22960 22355 21566 20602 19476 18203 16803 15296 13706 12063 10395 8737 7123 5593 4187 2947 1917 1141

659

500

20

25583 25870 25954 25832 25504 24972 24241 23319 22218 20951 19536 17992 16342 14614 12835 11038 9257 7531 5899 4403 3087 1996 1176

667

500

21

28231 28433 28420 28190 27743 27083 26217 25154 23907 22491 20924 19230 17431 15556 13636 11704 9796 7953 6214 4625 3231 2078 1212

676

500

22

31034 31141 31020 30670 30094 29296 28285 27071 25669 24095 22370 20516 18561 16533 14465 12393 10354 8388 6540 4855 3380 2162 1249

685

500

23

33993 33993 33753 33273 32557 31611 30445 29071 27505 25764 23872 21852 19733 17546 15325 13106 10930 8838 6877 5092 3533 2248 1287

694

500

24

37111 36993 36622 36001 35135 34030 32699 31155 29416 27500 25432 23239 20949 18595 16214 13843 11525 9303 7224 5337 3691 2337 1326

703

500

62

2.8k. Supplemental Payoff Table 1-1 (for the Actual Experiment ○○Your Investment Number
Your
Payoff

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

0
1
2
Your

3

Opponent's

4

Investment

5

Number

6

1484

2446

3066

3246

2902

2127

1200

581

3245

4512

5057

4921

4109

2821

1460

609

5705

7036

7332

6749

5383

3536

1724

636

9122

10295

10154

8952

6883

4364

2024

667

13575

14338

13553

11545

8620

5310

2364

701

19132

19206

17555

14548

10603

6376

2743

739

25855

24939

22187

17973

12838

7567

3163

781

33800

31573

27472

21836

15336

8887

3626

827

7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

63

2.8l. Supplemental Payoff Table 1-2 (for the Actual Experiment) O O
Your Investment Number

Your
Opponent's
Investment
Number64

24

2.8m. Payoff Table 2 (for the Actual Experiment)○ ×Your Investment Number

Your
Payoff

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

706

871 1072 1297 1536 1775 2003 2210 2386 2523 2615 2658 2648 2585 2470 2309 2106 1871 1614 1349 1091

21

22

23

24

858

669

543

500

21

22

23

24

65

2.8n. Supplemental Payoff Table 2-1 (for the Actual Experiment)○ ×Your Investment Number0Your
Payoff

1

2
986

3

4

5
1771

6

7

8
2373

9

10

11
2640

66

12

13

14
2455

15

16

17
1864

18

19

20
1100

571

2.8o. Supplemental Payoff Table 2-2 (for the Actual Experiment) ○ ×

3000

2500

2000

1500

1000

500

0
0

1

2

3

4

5

6

7

8

9

10

11

12

13

67

2.8p. Payoff Table 3 (for the Actual Experiment

×

○

Your
Payoff

0

706

Your

1

905

Opponent's

2

1186

Investment

3

1554

Number

4

2017

5

2578

6

3244

7

4018

8

4904

9

5907

10

7031

11

8278

12

9653

13

11158

14

12796

15

14570

16

16484

17

18539

18

20739

19

23086

20

25583

21

28231

22

31034

23

33993

24

37111

68

14

15

16

17

18

19

20

21

22

23

24

2.8q. Supplemental Payoff Table 3-1 (for the Actual Experiment)

×○Your Payoff

0
Your

1

Opponent's

2

Investment

3

Number

4

1088

5

2613

6
7
8

4943

9
10
11

8321

12
13
14

12841

15
16
17

18588

18
19
20

25633

21
22
23

34046

24

69

2.8r. Supplemental Payoff Table 3-2 (for the Actual Experiment) ×○

40000

35000

30000

Your Payoff

25000

20000

15000

10000

5000

0
0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

Your Opponent's Investment Number

70

15

16

17

18

19

20

21

22

23

24

3. Data for the Tsukuba Session A
3.1. Pairs of Subjects (ID Numbers)
Period

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1,6 1,5 1,10 1,3 1,16 1,8 1,12 1,9 1,11 1,17 1,13 1,18 1,2 1,19 1,4
2,10 2,8 2,18 2,4 2,11 2,14 2,3 2,16 2,20 2,13 2,5 2,15 3,20 2,17 2,63,9 3,7 3,17 5,20 3,10 3,13 4,20 3,15 3,19 3,12 3,4 3,14 4,19 3,16 3,54,8 4,6 4,16 6,19 4,9 4,12 5,19 4,14 4,18 4,11 6,20 4,13 5,18 4,15 7,20
ID #5,7 9,20 5,15 7,18 5,8 5,11 6,18 5,13 5,17 5,10 7,19 5,12 6,17 5,14 8,19
11,20 10,19 6,14 8,17 6,7 6,10 7,17 6,12 6,16 6,9 8,18 6,11 7,16 6,13 9,18
12,19 11,18 7,13 9,16 12,20 7,9 8,16 7,11 7,15 7,8 9,17 7,10 8,15 7,12 10,17
13,18 12,17 8,12 10,15 13,19 15,20 9,15 8,10 8,14 14,20 10,16 8,9 9,14 8,11 11,16
14,17 13,16 9,11 11,14 14,18 16,19 10,14 17,20 9,13 15,19 11,15 16,20 10,13 9,10 12,15
15,16 14,15 19,20 12,13 15,17 17,18 11,13 18,19 10,12 16,18 12,14 17,19 11,12 18,20 13,14

3.2. Investment Numbers of Each Subject in the Tsukuba A Session
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1

2

8
7
8
8
6
7
8
6
7
6
7
7
7
7
7

3

8
8
8
8
8
8
8
8
8
8
8
8
8
8
8

4

6
3
8
5
8
8
8
8
8
7
8
8
8
8
6

5
6 7 8
9 10 11 12 13 14 15 16 17 18
7 7 8
3 7 8
8 7 8
9 8 6
9 6
8
7 4 5
3 6 5
8 7 8
8 8 8
9 7
8
8 6 9
3 8 0
8 7 8
7 7 8
9 7
7
8 10 8
3 8 5
8 7 8
8 7 7
7 7
7
8 6 8
3 7 6
8 7 8
8 8 7
9 7
8
7 8 12 3 7 13 8 7 8
7 7 6
9 7
8
7 6 12 3 8 5
8 7 8
7 7 8
6 7
7
8 7 12 3 8 4
8 7 8
8 4 8
6 7
8
8 6 5
3 7 5
8 7 8
8 8 8
7 7
7
7 7 5
3 8 7
8 7 8
6 8 9
7 8
7
7 6 8
3 8 8
7 8 8
7 8 8
6 8
7
7 18 8
3 8 8
8 8 8
6 7 7
6 8
7
8 6 8
3 8 8
8 8 8
8 7 7
7 8
7
8 6 8
3 8 8
8 8 10
8 7 7
7 8
7
8 6 8
3 8 8
8 7 8
8 7 6
5 8
7

19 20
8 8
10 8
9 7
8 8
8 7
12 8
12 7
3 8
4 8
4 8
4 8
5 8
8 8
8 8
6 8

71

3.3. Investment Numbers of Each Subject's Opponents in the Tsukuba A Session
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1

2

8
4
8
5
9
7
8
4
7
8
7
7
8
8
8

3

8
6
7
8
7
7
8
6
8
6
6
7
7
8
8

4

8
3
7
8
8
7
8
8
4
8
7
7
8
7
6

5
6 7 8
9 10 11 12 13 14 15 16 17 18 19 20
7 3 8
7 7 6
8 8 8
8 6 9
6 8
9 8 7
5 7 7
3 8 8 10 8 7
9 8 8
8 8
7 8 5
9 8 7
7 8 7
8 0 8
3 9 6
8 8
8 7 9
8 8 8
7 7 7
7 7 8
8 7 8
5 8
3 8 10
6 7 3
8 6 8
8 8 7
8 8 7
6 7
8 8 8
8 7 8 13 7 3 12 8 7
8 8 8 12 87 9 6
7 12 7
7 6 8
7 7 8
7 8 5
8 3 12 6 7
4 8 8
7 8 6
8 3 12
7 8 8
8 8
3 8 7
7 7 7
8 8 8
8 7 8
5 7 3
5 6
8 8 8
7 8 7
8 3 5
7 7 7
8 8 4
7 6
7 9 8
8 8 8
4 7 8
6 8 8
7 8 8
7 8
8 3 8
6 8 8
8 8 8
3 8 18
7 8 8
8 5
7 8 6
8 7 8
7 7 7
8 8 8
8 8 8
3 8
6 8 8
7 7 8 10 8 8
8 8 3
8 6 8
8 8
8 7 7
7 6 8
8 6 7
8 5 6
7 8 8
7 8
8 8 3

72

3.4. Pairs of Investment Numbers in the Tsukuba A Session (boldfaced numbers indicate data of subjects who did spiteful behavior).
Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #
1,6
2,10
3,9
4,8
5,7
11,20
12,19
13,18
14,17
15,16

8
8
6
7
7
7
8
9
8
6

8
8
8
7
3

1,5
2,8
3,7
4,6
9,20
8 10,19
8 11,18
8 12,17
6 13,16
9 14,15

7
8
3
7
5
8
7
8
8
8

4
6
3

1,10
2,18
3,17
5 4,16
8 5,15
10 6,14
8 7,13
7 8,12
9 9,11
8 19,20

8
8
8
8
6
9
3
8
0
9

8
1,3
7
2,4
7 5,20
9 6,198 7,18
7 8,17
7 9,16
8 10,15
7 11,14
7 12,13

8
8
10
8
3
8
5
8
7
8

5 1,16
8 2,11
8 3,10
8
4,9
7
5,8
7
6,7
7 12,20
7 13,19
7 14,18
8 15,17

6
8
8
8
6
8
8
8
8
7

9
7
8
6
7
3

1,8
2,14
3,13
4,12
5,11
6,10
7
7,9
8 15,20
8 16,19
7 17,18

7
8
8
7
8
12
3
6
9
7

7 1,12
72,3
7 4,20
8 5,19
7 6,18
8 7,17
13 8,16
8 9,1512 10,14
8 11,13

8
8
7
6
12
3
8
5
8
7

8
1,9
8 2,16
7 3,15
12 4,14
7 5,13
7 6,12
6 7,11
8 8,107 17,20
7 18,19

6
8
8
8
7
12
3
8
7
8

4
6
8
4
8
8
7
8
8
3

Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #
1,11
2,20
3,19
4,18
5,17
6,16
7,15
8,14
9,13
10,12

7
8
8
8
6
5
3
7
5
8

7
8
4

1,17
2,13
3,12
7 4,11
7 5,10
76,9
8
7,8
8 14,20
8 15,19
8 16,18

6
8
7
7
7
5
3
8
9
7

8 1,136
2,5
8
3,4
7 6,208 7,19
7 8,18
8 9,17
8 10,16
4 11,15
7 12,14

7
8
8
8
3
8
8
7
8
8

7
6
7
8
4

1,18
2,15
3,14
4,13
5,12
7 6,11
8 7,10
68,9
8 16,20
8 17,19

7
8
8
7
18
8
3
8
6
8

7
7
7

1,2
3,20
4,19
6 5,18
8 6,17
8 7,16
8 8,15
8 9,14
8 10,13
5 11,12

7
8
8
6
8
3
8
8
8
8

8
8
8
7
8
7
7
7

1,19
2,17
3,16
4,15
5,14
6,13
7,12
8,11
8 9,108 18,20

7
8
8
8
6
8
3
8
8
7

8
8
7
7
7

1,4
2,6
3,5
7,20
8,19
8 9,1810 10,17
8 11,16
8 12,15
8 13,14

7
8
6
3
8
8
8
7
8
8

8
8
6
8
6
7
8
5
6
7

73

3.5. Payoffs of Each Subject in the Tsukuba A Session
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1
7345
4281
7345
5064
8209
6478
7345
4078
6478
7237
6478
6478
7340
7340
7340

2
7345
5766
6526
7345
6526
6526
7345
5766
7345
5766
5766
6526
6526
7345
7345

3
7237
2575
6526
7038
7345
6526
7345
7345
4420
7340
6526
6526
7345
6526
5515

4
5
6478 3675
4950 5812
8225 7237
7345 7056
5766 6339
7340 6526
6478 11589
4420 7340
6526 6339
6478 7340
7340 7237
5681 2886
7345 6339
6526 6339
6526 5515

6
77345 5440
6115 2575
6481 5440
7345 5440
3831 6383
6385 12589
5800 5440
6385 5440
6115 6383
6115 6383
7345 3160
7345 6383
7345 5440
7345 8561
7345 6383

8
6478
7237
7345
6526
5681
6478
5766
7345
7340
3831
6526
7345
6526
7345
5766

9
10
5766 7345
7038 9168
4018 7345
6115 6526
7237 7345
3626 11242
7038 6526
4960 7345
7038 7345
4950 6526
7345 5681
7345 3831
6526 7345
7345 7345
6526 7345

74

11
12
7340 7345
7340 6526
2210 7345
6478 7345
7340 6526
7340 6526
6478 7345
3675 11242
6478 7345
6478 6526
7345 7345
7345 19057
7345 7345
7345 3952
4950 5766

13
7250
8225
3675
7345
7345
7340
6478
6526
5064
7237
6478
6339
7345
7345
6526

14
5766
7345
8271
6478
7345
7340
7340
6751
6526
7345
7345
7340
7340
5681
7340

15
16
8209 5765
7345 7250
5766 7250
7340 4950
6478 5765
7237 10877
5064 7237
7345 7237
3831 4950
4488 6478
7345 6339
7340 7237
7340 3675
7340 7340
7237 6115

17
187237 8225
7340 6526
7340 7340
7340 3675
6478 7345
7340 6526
3675 11480
7340 3831
5681 7340
5766 6478
7345 7340
5064 6478
7345 5681
7345 7340
7345 7340

19
7345
7056
6481
7345
7345
7007
5249
6383
6751
7779
2902
7038
7345
6526
7237

20
6526
5064
8271
9168
7340
5766
6478
6526
7345
7345
7345
5766
7345
6526
3831

3.6. Record Sheets and Questionnaires for the Tsukuba A Session

ID Number = 1, Male, Earnings = 2431 yen

ID Number = 1, Male, Earnings = 2431 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.

Practice

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
11
Because my opponent would make a safe investment.
84381
I chose a middle number for a trail.
24
I tried to surprise my opponent.
9500
5Because I expected that my opponent's investment
7
number would be between 10 and 12, not more than 14.
3381
8Everyone will steadily invest around 7-9 units. So I
95080
chose 8 which would be most profitable among them.

The Actual Experiment
Period 1
8
Because there is a strong likelihood that my opponent'
investment number is between 7 and 9, I chose a similar
number.
Period 2
7
The same reason as at period 1.
Period 3
8
Because my opponent would steadily invest around 7-9
units.
Period 4
8
There are many periods to play. Everyone is steady.
Period 5
6
I tried to make my opponent suffering a little loss. My
opponent would invest at 7-9 units.
Period 6
7
Both my opponent and I would receive reasonablepayoffs by choosing this number.
Period 78
My opponent's investment number would be between 5
and 7. This investment number 8 would be best for me.
Period 8
6
I spited my opponent to reduce his payoff a bit.
Period 9
7
By choosing 7, I can cope with any investment number ofmy opponent.
Period 10
My opponent's payoff when I choose 6 is much smaller
6
than that when I chose 8, while my payoff does not differ
much. I spited him.
Period 11
7
The same reasons as in period 10. My opponent would
have the same idea.
Period 12
7
By choosing 7, I would get a reasonable payoff and my
opponent would not blame me.
Period 13
7
The same as the above. A prisoner's dilemma situation.
Everyone would have the same idea.
Period 14
7
The same as the above.
Period 15

7

The same as the above.

75

8

7345

4
8

4281
7345

5
9

5064
8209

7

6478

8

7345

4
7

4078
6478

8

7237

7

6478

7
8

6478
7340

8

7340

8

7340

(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
The payoffs for investment numbers which would be hardly chosen are highest. My payoffs differ
much if my opponent's investment numbers differ by 1, while they differ little if my investment
numbers differ by 1.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
5. If my payoff is the same as my opponent's payoff, I do not care about the absolute valueof my payoff.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

50

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
Most of my opponents chose 6-8 safely. So I usually chose 6-8, too. However, I chose 6 or 7 manytimes, because I did not like that my opponent's payoff was higher than mine.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
Choose 6 if you want to get a larger payoff than your opponent's payoff. The difference of yourpayoff between choosing 6 and choosing 8 is relatively small, while the difference of youropponent's payoff is quite large. If it is desirable that both you and your opponent get large
payoffs, choose 8 because your opponent almost always chooses 6-8.

76

ID Number = 2

MaleEarnings = 2494 yen

ID Number = 2

Period 2
Period 3
Period 4

Earnings = 2494 yen(1) Did you understand the rules of the experiment?

Practice

Period 1

Male

Your
Your The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
7
My opponent would safely choose 12 at the first time.
84368
Choosing 7 is best for me when my opponent chooses 12.
10Because I expected that everyone would invest around 76
3520
12 units initially.
10
My opponent would decrease investment numbers. I
23
16993
chose 10 despite of a failure in period 2.
3
2340
13
Already psychological warfare. Someone went on thegamble. My opponent would also realize the situationand choose an investment number carefully. I chose 13
to maximize my payoff when both I and my opponent
choose the same number.

The Actual Experiment
Period 1
8
My opponent would carefully choose a number at thefirst time. Both my opponent and I get reasonablepayoffs if both chose 8.
Period 2
8
The same reasons as above. My opponent changes, but
he would have a similar idea.
Period 3
8
At first glance, I might make a mistake at period 2. Butchoosing 8 would be best for me, regardless of which
number my opponent chose.
Period 48My expectation at period 3 was correct. Choosing 8 isbest for me if my opponent chooses a number between 6
and 8.
Period 5
8
I am pretty sure now. I will continue to choose 8 as longas my opponent has the same idea.
Period 68
Someone does not understand the situation. But he will
eventually choose 8.
Period 7
8
I am in trouble. Choosing 8 is absolutely better thanchoosing 7. I have nothing to write about the reasons.
Everyone will end up choosing 8.
Period 8
8
I will continue to choose 8 through period 15.
Period 98
There is no meaning for reducing the payoff of the
opponent. I would like to tell my opponent that heshould focus on his own payoff. My payoff is higher
when my opponent chooses 8 than when he chooses 6.
Period 10
8
Sorry, I have nothing to write down.
Period 11
8
I heave a sigh. Someone does not understand thesituation.
Period 12
8
I would like to ask my opponent why he chose 6.
Period 13
8
I would like to ask my opponent why he chose 7.
Period 14
8
Why? I wish my opponent chooses 24.
Period 15
8Thank you. I am glad to notice that everyone would end
up choosing 8. If the rule of choosing 8 do not emerge, I
would go on the gamble.

77

8

7345

6

5766

7

6526

8

7345

7

6526

7

6526

8

7345

6
8

5766
7345

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
At practice periods, I took a look at Payoff Table 3 only. It helped me understand payoffs roughly.
I used Payoff Table 2 to see how I can get a large payoff actually, when we had 10 minutes to look at
the payoff tables before the actual experiment. Once the actual experiment began, I looked only at
Payoff Table 1. For the chosen investment numbers were already limited and so detailed
information on payoffs became important. However, it was difficult for me to decide investment
numbers immediately without using Payoff Tables 2 and 3.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.

6
6

5766
5766

7
7
8
8

6526
6526
7345
7345

(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

27

) % of expectations came true.

4 out of 15.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
At practice periods I found that one should decide his investment to maximize his own payoff, but
not run a risk. I behaved on the presumption that everybody realized this fact. Some persons
seemed not to realize it even at the actual experiment, although they chose numbers close to 8.
Perhaps they might not look at the detailed payoff table, Table 1, when deciding investment
numbers.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
At practice periods I was puzzled how much I should invest because I did not have enough time toconsider. But I found investing 8 best because it was most profitable for any investment number ofmy opponent. Further, investing 8 have regularly been observed. Without this regularity, I might
go on a gamble.

78

ID Number = 3

FemaleEarnings = 2381 yen

ID Number = 3

Practice

Period 1

Period 2
Period 3
Period 4

FemaleEarnings = 2381 yen(1) Did you understand the rules of the experiment?
Your
Your The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)12
If I choose at least 18, my payoff is low, regardless of8
4213
which number my opponent chooses. My opponent
would have the same idea. Therefore I chose a middle
investment number.
9
Because my payoff was much smaller than my
137844
opponent's at the previous period, I reduced myinvestment number.
7
I expected that my opponent's investment number
73790
would be between 10 and 15, and so I chose a small
number again.
10
I expected that my opponent would choose a relatively
20
13690
small investment number, and so I chose a number
larger than my number at the previous period.

The Actual Experiment
Period 1
6
I expected that my opponent would invest at least 10
units.
Period 2
3
I expected that my opponent would choose a larger
investment number. I bravely chose a small investment
number.
Period 3
8
I expected that my opponent's investment number
would be between 7 and 9.
Period 4
5
I expected that my opponent would choose a relatively
large investment number.
Period 5
8
So far most opponents have invested 7 or 8 units. I
expected such investment numbers from this trend.
Period 6
8
I expected the same trend as in the previous period.
Period 7
8
Because everyone seems to have the same idea, I havethe same expectation as before.
Period 8
8
The same as in the pervious period.
Period 98
The same as in the previous period. Most people would
have chosen 8.
Period 10
7
I expected that my opponent would invest around 12
units.
Period 11
8
I judged that it is safest to invest 8 units.
Period 12
8
The same as the above.
Period 13
8
The same as the above.
Period 14
8
The same as the above.
Period 15
6
I expected that my opponent might choose a little larger
number at the final round.

79

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
First I looked at Table 3 to understand roughly how my payoff depends on my investment number
and my opponent's. At each period I expected my opponent's investment number and considered
how much I should invest under that expectation by looking at Table 2. Then I decided a number
from Table 1.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.

8

7237

3

2575

7

6526

8

7038

8

7345

7
8

6526
7345

8
4

7345
4420

8

7340

7
7
8
7
6

6526
6526
7345
6526
5515

(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

80

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
Most people have learned of investment and trended to invest similar amounts as periods
advanced. Once the trend established, it seemed to me that everybody became conservative anddid not go on a gamble. I ventured to invest small units to get large payoffs. However, because I
anticipated that my opponent would invest around 8, I also invested 8 at most periods. At period
15, I slightly changed my investment number because it was final, but my opponent had the exactly
same idea. I had more fun at practice periods because my opponents invest various amounts.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
I think it is good to expect my opponent's investment calmly and make a steady investment. But
such a investment is not interesting. But a risky investment might lead to a low payoff if my
expectation proves wrong, and so it would not be economically efficient.

80

ID Number = 4 Female Earnings = 2436yen

ID Number = 4 Female Earnings = 2436 yen

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
8
My payoff is small if I choose a large or a small
138018
investment number. Therefore I expected that my
opponent would choose a number between 8 and 16.
9
By Table 2, I thought that choosing 9 is most profitable.
73980
6There is a high possibility of my opponent's number
84201
being between 13 and 21.
9
I would receive most profitable payoff by choosing 9 if
95087
my opponent notice that it is efficient to choose anumber between 7 and 9

The Actual Experiment
Period 1
7
There is a high possibility of my payoff being at least
6000 if investment numbers are between 8 and 11. If my
opponent chooses a number between 7 and 11, then theprobability of getting a high payoff is best by choosing 7
or 8.
Period 2
7
Choosing this number is efficient if my opponent
chooses 7 or 8.
Period 3
8
Choosing this number is efficient even if my opponent
chooses a small number.
Period 4
8
I expected that my opponent would choose a number
around 7, and I chose the number inducing the largest
payoff under that expectation.
Period 5
8
I expected that my opponent would choose a number
around 7. Choosing this number is efficient.
Period 6
7
I expected that my opponent would choose a number
around 9.
Period 7
7
I expected that my opponent would choose a number
around 9.
Period 8
8
I expected that my opponent would choose a relatively
small number (6-8).
Period 9
8
I expected that my opponent would choose a number
around 7.
Period 10
7
I expected that my opponent would choose a number
around 9.
Period 11
7
I expected that my opponent would choose a number
around 9 because small numbers have been continuously
observed.
Period 12
7
I expected that my opponent would choose a number
around 9.
Period 13
8
I expected that my opponent would choose a number
around 6, because he attempted to make his opponent's
payoff small.
Period 14
8
Choosing this number assures a reasonable payoff even
if my opponent chooses a small number.
Period 15
8
I expected that my opponent would choose 7 or 8 toreceive a reasonable payoff with a high probability.

81

7

6478

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
At practice periods I mainly used Payoff Table 2. But it is so rough that I can only compare theaverage payoffs. In the actual experiment I used Payoff Table 1 to examine most profitable
investment. Payoff Table 3 help me understand my opponent's state of mind.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) What did you think about your opponent's investment?

5

4950

9

8225

8

7345

6

5766

8

7340

7

6478

4

4420

7

6526

7

6478

8

7340

6

5681

8

7345

7

6526

7

6526

1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

75

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
There was a cycle such that a large number came after a small number came, and so on. On
average, middle numbers leading to constant payoffs have been observed. But I did not makeinvestments based on the expectation of a cyclical investment pattern. Rather I chose myinvestment numbers applicable to several numbers of my opponent.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
First, decide your target payoff. Someone wants to reduce his opponent's payoff. Keep this in mind
when choosing investment numbers. If your actual payoff is low than the target, choose a number
which would result in a reasonable payoff safely. If your actual payoff is larger than the target, try
a number which might result in a larger payoff.

82

ID Number = 5, Male, Earnings = 2439yen

ID Number = 5, Male, Earnings = 2439 yen

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
11
I chose a safe number at the first time. My opponent also
63490
tried to see what happened.
24
Because I would like to spend all 24 units once.
12500
0Because I might get a lot of money.
61416
9Because I expected that my opponent would choose a95087
large number.

The Actual Experiment
Period 1
7
Because I expected that my opponent would not choosea large number.
Period 2
4
I tried to make a lot of money.
Period 3
6
I chose a safe number
Period 4
10
I would like to use a two-digit number once in a while.
Period 5
6
Because my opponent would not choose a large number.
Period 6
8
By intuition.
Period 7
6
Choosing 6 would be best for me.
Period 8
7
Choosing this number is safe.
Period 9
6
From my success in period 7.
Period 10
7
7 is a lucky number.
Period 11
6
Because I want to avoid a risk.
Period 12
18
Because I would like to make my opponent happy
occasionally.
Period 13
6
Because I made a mistake in the previous period.
Period 14
6
Because choosing 6 is best for me.
Period 15
6
Because I would like to choose 6 at the final round.

3

3675

7
8
8
7
7
12
8
7
8
8
8

5812
7237
7056
6339
6526
11589
7340
6339
7340
7237
2886

7
7
6

6339
6339
5515

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
I most often referred to Payoff Table 3. Payoff Table 1 helped me examine detailed payoffs.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

80

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
My opponents almost always chose 7 or 8. It was not fun at all. I wished my opponents to invest 24
sometimes. Therefore I should inevitably chose 6 or 7 at most periods. I chose a different number,
18, only once, but the others solely chose 7 or 8.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
The best choice would be to make investments steadily, but not to run any risk. However, if
everybody takes this choice, there is little difference in payoffs. If I continue to choose 6 or 7, I could
have victories over my opponents to some degree.

83

84

ID Number =6, Male, Earnings = 2466yen

ID Number =6, Male, Earnings = 2466 yen

Practice(1) Did you understand the rules of the experiment?

Period 1

Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
6
Nobody would choose an investment number between
116335
13 and 24. I wish to secure at least 1000 payoff. I
expected that my opponent would choose 12. Thenchoosing 6 or 7 leads to a high payoff.
3
I want to try several numbers in practice.
104769
I attempted to make my opponent's payoff small.
0
My opponent would not choose more than 13.
7
1815
I wish to make my opponent disappointed.
20
My opponent would choose 6, 7 or 11, 12.
101505
I tried to make my opponent happy once in a while.

The Actual Experiment
Period 1
8
My opponent would choose 5,6,7 or 10,11,12.
I chose a middle number.
Period 2
5
My opponent would attempt to get payoffs safely.
Period 3
9
I recognized I cannot receive a high payoff at once.
Period 4
8
My opponent would choose 6, 7, or 8. Choosing thisnumber would be best if he chose any of them.
Period 5
8
My opponent would also choose 8. Choosing thisnumber would be best if he did so.
Period 6
12
I would like to provoke my opponent, although I know
my payoff might decrease.
Period 7
12
The same as the above.
Period 8
12
The same as the above.
Period 9
5
My opponent would choose 7 or 8. I shake myopponent,
as long as I can avoid a big loss.
Period 10
5
The same as the above.
Period 11
8
I recognize that provoking my opponent does not makea sense, and I choose a safe number.
Period 12
8
The same as the above.
Period 13
8
The same as the above.
Period 14
8
The same as the above.
Period 15
8
The same as the above.

85

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
Payoff Table 3 is little meaningful.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.

8

7345

7
7
8

6115
6481
7345

3

3831

8

6385

7
8
7

5800
6385
6115

7
8

6115
7345

8
8
8
8

7345
7345
7345
7345

(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

80

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
Because it was tedious to make safe investments, I behaved more aggressively, but I failed.
I think my opponents would try not to suffer a loss, rather than to get a large payoff, because thistwo-person investment game is just an experiment.
The situation would change if the payment is much higher and the payoff is different so that wemight suffer a big loss for some investment.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
Try to realize the character of the opponent (it may not be possible because the number of periods islimited).
1) At early periods, choose 18-20 to induce the opponent to do the same thing and consider the
progress of a battle.
2) Choose 8 at all periods.
3) Choose 20 at all periods and collect the loss after the experiment (this will not go well if there issomebody else who also scarifies his own payoff).

86

ID Number = 7, Male, Earnings = 2286yen.

ID Number = 7, Male, Earnings = 2286 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
13
I expected that my opponent would invest 13 units.
83981
9I expected that my opponent would choose an7
3980
investment number between 1 and 10.
7
I expected that my opponent would choose 8 or 9.
52792
3I expected that my opponent would choose a small
137447
investment number.

The Actual Experiment
Period 1
3
Based on my experiences in practice, I thought I could
make a profit by choosing a number which is smaller
than my opponent's number. I expected that my
opponent would not choose a large number.
Period 2
3
The same as the above.
Period 3
3
The same as the above.
Period 4
3
The same as the above.
Period 5
3
The same as the above.
Period 6
3
The same as the above.
Period 7
3
The same as the above.
Period 8
3
The same as the above.
Period 9
3
The same as the above.
Period 10
3
The same as the above.
Period 11
3
The same as the above.
Period 12
3
The same as the above.
Period 13
3
The same as the above.
Period 14
3
The same as the above.
Period 15
3
The same as the above.

7

5440

3
7
7
8
13
7
7
8
8
4
8
7
10
8

2575
5440
5440
6383
12589
5440
5440
6383
6383
3160
6383
5440
8561
6383

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
I referred to Payoff Table 1 only. Tables 2 and 3 were little helpful. I think the possibility of failure
would become larger if I refer to them.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
2. If my payoff is higher than my opponent's payoff, I do not care about the absolute valueof my payoff, even when the difference between my payoff and my opponent's is small.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

80

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
Investing 7 or 8 were frequently observed. This would be because both could get reasonablepayoffs safely. Because I always wanted to get a larger payoff than my opponent's, I always chose 3
in an attempt to enlarge the difference between my payoff and my opponent's by choosing a small
number.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
I think the best situation is that both of us get large payoffs. But it did not go well because people
had different opinions. At a practice period I invested 13 and expected my opponent to invest asimilar amount, but I was betrayed. So I decided to reduce my opponent's payoff. Off course, theexperimenters do not welcome this. At every period of the actual experiment, I received a larger
payoff than my opponent's. But I do think my earnings is much larger than others'. I want to get
more money than others get. I am satisfied with my strategy in this experiment.

87

88

ID Number = 8, Female, Earnings = 2438yen.

ID Number = 8, Female, Earnings = 2438 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
8
Because I expected that my opponent would write a12
7206
middle number at the first time.
10
Because I expected to receive a reasonable payoff.
63520
7Because I expected that my opponent would not write a01148
large number.
10
Because I expected to receive a reasonable payoff,
95019
although my opponent's payoff might be low.

The Actual Experiment
Period 1
7
Because I expected that my payoff would not be bad bylooking
at the tables.
Period 2
6
Because I expected that my opponent would not choosea large investment number.
Period 3
8
Because I expected that my opponent would choose asimilar investment number.
Period 4
8
Because my opponents have chosen a number around 8.
Period 5
7
Because I still expected that my opponent would choose
a number between 6 and 8.
Period 6
7
Because I expected to receive a reasonable payoff.
Period 7
8
Choosing 6 and 7 have continued. I expected 6 or 7
again.
Period 88Because I expected that my opponent would choose asimilar number.
Period 97
Because I expected to receive a reasonable payoff.
Period 10
8Choosing 8 have continued these few periods. I
expected to receive a reasonable payoff by choosing 8.
Period 11
8
Because I expected to receive a reasonable payoff.
Period 128
Because I expected that my opponent would choose asimilar investment number.
Period 13
8
Because so far I have received a reasonable payoff bychoosing 8.
Period 148
Because I expected to receive a reasonable payoff.
Period 15
8
Because I thought I could get the best payoff by choosing
8 after all.

89

7

6478

8

7237

8

7345

7
6

6526
5681

7
6

6478
5766

8

7345

8
3

7340
3831

7
8

6526
7345

7

6526

8
6

7345
5766

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
First I used Payoff Table 3 to understand payoff structure roughly. Then, I looked at Payoff Table 2
to decide investment numbers at practice periods and periods 1-3 of the actual experiment. I used
Payoff Table 1 at both practice and the actual experiment.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

80

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
My investment numbers were similar to my opponents' at most periods. I chose an investment
number in an attempt to get the largest payoff under the expectation that my opponent would
choose a similar number.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
Off course I am happy if I receive a large payoff. But I realized from Payoff Table 1 that I would not
get a large payoff if I consider my payoff only. If I decide an investment number so that my
opponent would receive a reasonable payoff by investing this number, then I would also receive areasonable payoff. The best choice would be to make an investment decision so that both my own
payoff and my opponent's are reasonably high. It is not to choose an investment number to entrap
my opponent.

90

ID Number = 9, Male, Earnings = 2303 yen.

ID Number = 9, Male, Earnings = 2303 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3

Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
8
By intuition.
73915
5
I expected that my opponent would choose a number
137956
between 13 and 21, and I chose a number maximizing
my payoff.
01007
6
I expected that my opponent would choose a number
between 19 and 24. If this expectation was true, I could
get the highest payoff by choosing a number between 0
and 3. But this is rather risky and so I chose a larger
number.
8
Because I expected that my opponent would choose a95080
middle number, I chose a safe number.

The Actual Experiment
Period 1
8
I expected that my opponent would choose a number
between 0 and 9. Choosing 8 ensures a mean payoff.
Period 2
5
I expected that my opponent would choose a number
between 10 and 15. By choosing 5, I would get thehighest payoff.
Period 30
I expected that my opponent would choose a number
between 19 and 24. I chose 0, although I knew it is risky.
Period 4
5
By choosing this number, I would receive good payoffs
on average.
Period 5
6
I expected that my opponent would choose a number
between 10 and 18.
Period 6
13
I was bored by choosing a number between 5 and 8.
Period 7
5
I expected that my opponent would choose a number
between 5 and 8. Choosing this number would
guarantee a mean payoff.
Period 8
4
I expected that my opponent would choose a large
number between 10 and 24.
Period 95
I expected that my opponent would choose a number
between 5 and 8. Choosing this number would
guarantee a mean payoff.
Period 10
7
Because I expected that my opponent would choose anumber between 6 and 8.
Period 11
8
Because I expected that my opponent would choose 8.
Period 128
Because I expected that my opponent would choose anumber between 4 and 9.
Period 13
8
The same as the above.
Period 14
8
The same as the above.
Period 15
8
The same as the above.

91

6

5766

8

7038

7

4018

7

6115

8

7237

3
8

3626
7038

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
I looked at Payoff Table 2 to decide my investment number. My payoff is not large when I choose alarge investment number. This is different from the usual risky investment. Further, even when I
choose a small investment number, my payoff is low unless my opponent's investment number islarge. I realized that I cannot expect to receive a large payoff.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

50

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
Everybody have steadily invested 5-8 from the begging of the experiment. Therefore I havecontinuously invested 8, which is most profitable for such investment numbers.

6

4960

8

7038

(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?

5

4950

8
8

7345
7345

I was mortified when my opponent's payoff was higher than mime. However, when I attempted tomake my opponent's payoff low, my payoff was often low, too. I believed I selected the best
method to maximize my payoff.

7
8
7

6526
7345
6526

92

ID Number = 10, Male, Earnings = 2707yen.

ID Number = 10, Male, Earnings = 2707 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1

Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
8
The payoff depends on my opponent's investment
105737
number, no matter whether I choose a small number or alarge number. Therefore everyone would choose a safe
number.
8
I did not expect my opponent would choose a large
105737
number.
8
Many people have written 10. I would receive the63405
highest payoff by choosing 8 if my opponent chose 10.
8
Is there anybody who tries to change such stereotyped
73915
behavior?

The Actual Experiment
Period 1
8
Everyone wants a high payoff. We would surely receive
reasonable payoffs if each of us tried to make both
payoffs high, rather than to establish a lead on his
opponent's for payoffs.
Period 2
8
My opponent would also prefer mean luck of both tobad luck of the other.
Period 3
8
At the previous period, my opponent got a higher payoffthan I did. But if I also reduced an investment number,then my payoff would decrease further.
Period 48Someone seems to have a similar idea.
Period 5
8
At the previous period the investment number of my
opponent was accidentally low.
Period 68This is it.
Period 78
Someone might want to change such stereotyped
behavior. But I will not do it.
Period 8
8
There were a little movement, but it would not prevail.
Period 98
I return to my original intention.
Period 10
8Everyone has constantly chosen 8.
Period 11
7
I feel that something might happen next time. Actually,
the difference of my payoff between (8, 8) and (7, 8) is
only 5.
Period 12
8
Small investment numbers have increased. But mypayoff would decrease if I also chose a small number.
Period 13
8
My opponent at the previous period tried to entice me,butit did not work.
Period 14
8
Stop useless struggling.
Period 15
8
Coexistence or exclusion.

93

2. I have understood the rules from a middle of the experiment:
From period ( 2) in Practice(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
I realized that my payoff is low both when I invest small units and when I invest large units. For asmall investment number, my payoff might be large only when my opponent chooses a large
investment number. But this would hardly happen. So I have patiently chosen investment
numbers so that both my payoff and my opponents' payoffs were reasonably high.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?

8

7345

10

9168

8

7345

7
8

6526
7345

12
7

11242
6526

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?

8
8
7
6

7345
7345
6526
5681

I invested the same amount at all periods except one. By contrast, my opponents sometimes
changed investment numbers (although my opponent changed at each period). Investment
numbers have been stable around 8, but they became unstable at the last few periods. At these
periods, my opponents decreased investment numbers, because they might have in mind that theyspited their opponents and they won victories over them.

3

3831

(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?

8

7345

8
8

7345
7345

3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

70

) % of expectations came true.

If I try to receive a larger payoff than my opponent's, the absolute value of my payoff would besmall, although it would be relatively larger. What is beneficial to me is not to win a game over myopponent, but to receive a lot of money. The good choice would be to make an investment decision
so that both I and my opponent would receive a lot of money.

94

ID Number = 11, Male, Earnings = 2387yen
PracticeYour The Reasons for Your Decision on Your Investment Number
Your
Invest- (Please specify your expectation on your opponent's
Opponent's Your
ment investment number and the reasons why you chose yourInvestment Payoff
Number investment number.)NumberPeriod 1
7
I expected that my opponent would choose the average
116432
number 12. I chose 7 to get the largest payoff when he chose 12.
Period 2
10
I expected that my opponent would choose a number between
84481
15 and 19. I chose 10 to get a reasonable payoff under that
expectation.
Period 3
7
My opponents have gradually decreased investment numbers.
7
3790
Therefore I chose 7 to get the largest payoff if my opponent
chose a number between 7 and 9.
Period 4
10
Choosing a small number around 7 was observed. I chose 10 to
84481
get the largest payoff if my opponent chose such a number.
The Actual Experiment
Period 1
7
From a few of results in practice, I expected that my opponent
8
7340
would choose a number between 7 and 9. I chose 7 to get thelargest payoff under that expectation.
Period 2
7
From data at the previous four periods, I expected that my
87340
opponent would choose a number between 7 and 9. I chose 7
to get a large payoff under that expectation.
Period 3
7
Because numbers between 7 and 9 have been continuously
02210
observed, I chose 7 again.
Period 4
7
I still expected that my opponent would choose a number
76478
between 7 and 9, although someone chose 0 at the previous
period. I chose 7 again.
Period 5
7
At seven periods except period 3, my opponents chose 7 or 8. I
87340
chose this number to get a large payoff when my opponent
chose the mean value.
Period 6
7
Because numbers 7 and 9 have been continuously observed, I
87340
has the same expectation.
Period 7
7
I chose this number to get the largest payoff if my opponent
76478
chose a middle number between 6 and 12.
Period 8
7
At all periods except practice period 1 and period 3 of the33675
actual experiment, my opponents chose 7 or 8. I expected
the same situation.
Period 9
7
I thought the investment number at the previous period was an
7
6478
exception. I expected a number between 7 and 9 again.
Period 10
7
I continue to choose 7 from period 1 to see what happens.
76478
Period 11
8
From period 1 to period 10 of the actual experiment,
87345
numbers equal to or larger than 10 have never been
observed and 7 and 8 have been observed at most periods. I
chose 8 to receive a large payoff for these numbers.
Period 12
8
I chose 8 to receive a high payoff when my opponent's
87345
investment numbers were between 4 and 10.
Period 13
8
Because choosing 8 would prevail, I also chose 8 to maximize
87345
my payoff.
Period 14
8
I expected that my opponent would also choose around 8 at
87345
this period, based on the experience at the pervious three
periods.
Period 15
7
Perhaps my opponent would choose 8, but he might choose an
5
4950
extreme number because this is the final period.

95

ID Number = 11, Male, Earnings = 2387 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
If both I and my opponent choose the same number, choosing 12 maximizes our payoffs. Therefore
I thought everybody would choose this number. However, choosing 7-8 prevailed. Consequently I
chose 7 or 8. My payoff is largest when my opponent chooses 24 and I choose 0, but there would be
no such a dupe.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

85

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
Because investment numbers became stable at 7-8 at practice periods, I expected investment
numbers to become stable around such numbers in the actual experiment, and the expectation
almost always came true. But at two periods I faced the opponents who chose an extremely small
number and so both received low payoffs. Overall, most of my expectations came true and I could
receive the highest possible payoffs.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
Both I and my opponent would receive reasonably high payoffs if both choose 10-12. However
there are some persons who tried to make his own payoff high. So the good choice would be toinvest 7-9, slightly lower than 10-12.

96

ID Number = 12, Male, Earnings = 2938yen

ID Number = 12, Male, Earnings = 2938 yen

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
9
I expected that my opponent would choose at least 10.
2
1945
13
Because I expected that my opponent would choose a52925
small number.
23
Because this is practice.
10
573
24
The same as the above.
5
500

The Actual Experiment
Period 1
8
I expected that my opponent would choose 8, and so I
chose 8 to receive the highest payoff if he did so.
Period 2
8
The same as the above.
Period 3
8
The same as the above.
Period 4
8
The same as the above.
Period 5
8
I expected that my opponent would absolutely choose 8.
I chose 8 to receive the largest payoff 7345 under that
expectation.
Period 6
8
The same as the above.
Period 7
8
The same as the above.
Period 8
8
The same as the above.
Period 98
The same as the above.
Period 10
8
The same as the above.
Period 11
8
The same as the above.
Period 12
8
The same as the above.
Period 13
8
By choosing 8, I can get a reasonable payoff for any
investment number of my opponent.
Period 14
10
I betted that my opponent would choose 13.
Period 15
8
Choosing 8 is almighty.

8

7345

7
8
8
7

6526
7345
7345
6526

7
8
12
8
7
8
18
8

6526
7345
11242
7345
6526
7345
19057
7345

3
6

3952
5766

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
Payoff Table 3 is useless. I initially used Table 2 a little, but I referred to Table 1 to decide myinvestment numbers because Table 1 gives more accurate payoff values. I thought that by investing
8, I could get a good payoff for any investment number of my opponent.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

50

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
Most of my opponents invested 8. I also invested 8, because I found from Payoff Table 1 that my
payoff is maximized by investing 8 when my opponent invests 8.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
I think the best choice is to invest 8. The reason is described in (7).

97

98

ID Number = 13, Male, Earnings = 2513yen.

ID Number = 13, Male, Earnings = 2513 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
11
Because I could receive a reasonable payoff by choosing
7
3918
this number.
6
Because I expected that my opponent's investment
10
5561
number would be larger than mine.
8
Because I expected that my opponent's investment
95080
number would be larger than mine.
5
Because I expected that my opponent's investment
83976
number would be close to the average number.

The Actual Experiment
Period 1
9Because I expected that my opponent's investment
number would be similar to mine.
Period 2
8
Because I expected that my opponent's investment
number would be similar to that at the previous period.
Period 3
7
The same as the above.
Period 4
8
Because I expected that my opponent's investment
number would be similar to mine.
Period 5
8
Because I expected that my opponent's investment
number would be similar to that at period 4.
Period 6
7
Because I expected that my opponent's investment
number would be close to 8.
Period 7
7
Because I expected that my opponent's investment
number would be similar to that at period 6.
Period 88Because I expected that my opponent's investment
number would increase.
Period 98
Because I expected that my opponent's investment
number would be 7 or 8.
Period 10
6Because I expected that my opponent's investment
number would be small.
Period 11
7
Because I expected that my opponent's investment
number would be close to 8.
Period 12
6
Because I expected that my opponent's investment
number would be close to 8.
Period 13
8
I expected that my opponent's investment number
would be 7 or 8.
Period 14
8
The same as the above.
Period 15
8
The same as the above.

99

2. I have understood the rules from a middle of the experiment:
From period ( 3) in Practice(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
I understood payoffs roughly by using Table 2, and I decided my investment numbers by using
Payoff Table 1.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?

8

7250

9

8225

3
8

3675
7345

8

7345

8

7340

7

6478

7

6526

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?

5

5064

Most of my opponents' investment numbers were 7 or 8, but some of them were less than 7.

8

7237

7

6478

(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?

7

6339

8

7345

8
7

7345
6526

3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

60

) % of expectations came true.

I think it is good to invest similar units, but not to change investment numbers extremely.

100

ID Number = 14, Male, Earnings = 2639yen.

ID Number = 14, Male, Earnings = 2639 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
8
I expected that my opponent would choose a clear-cut
73915
number, "10", at the first time. I chose the number
maximizing my payoff when he chose 10.
7
I tried the number which is smaller than that at previous
95000
period by 1.
9
I expected that my opponent's number would be 8 or 9
63491
from the experience at the previous two periods. This
number maximizes my payoff when he chooses 8 or 9.
9
The average value of opponents' numbers over the past
8
4512
three periods is 7.33. Choosing 9 maximizes my payoff
when my opponent chooses 7 or 8.

The Actual Experiment
Period 1
8
If both my opponent and I choose 8, I maximize my own
payoff for the number chosen by my opponent, and sodoes my opponent.
Period 2
8
The same as the above.
Period 3
7
I changed the investment number a little, because there
is little difference between choosing 7 and choosing 8.
Period 4
7
I expected that my opponent' number would be between
8 and 10.
Period 58
I lost my payoff at the previous period.
Period 6
7
I hoped my opponent's number would be large.
Period 7
7
Choosing 7 maximizes my payoff if my opponent
chooses 8 or 9. I thought my opponent would choose 9this time.
Period 8
4
I attempted to spite my opponent once. But, by choosing
3, I would also lose my payoff a lot. (The difference of
my payoff between choosing 4 and choosing 5 is muchsmaller than that between choosing 3 and choosing 4.)
Period 9
8
I recognized that choosing 8 was best after all. Because I
lost my payoff at the previous period, I wished tomaximize my payoff at this period.
Period 10
8
I recognized that choosing 8 was best after all. Because I
lost my payoff at period 8, I wished to maximize mypayoff at this period.
Period 11
8
I recognized that choosing 8 was best after all. Because I
lost my payoff at period 8, I wished to maximize mypayoff at this period.
Period 12
7
When my opponent chooses 8, the difference of mypayoff between choosing 7 and choosing 8 is only 5. I
just tried this number.
Period 13
7
The same as the above.
Period 14
7
The same as the above.
Period 15
7
The same as the above.

101

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
Table 2 is little useful. Tables 1 and 3 give detailed information on payoffs. First I referred to Table
3. But as periods advanced, I got used to more detailed Table 1 and then looked only at Table 1.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
6. Others (please specify).
First, "3" (it is desirable that both my payoff and my opponent's payoff are as high as possible). But
I thought that it would be hardly achieved because no communication was allowed. Later, almost
always "1" (it is desirable that my payoff is high, regardless of my opponent's payoff) and sometime"2" (if my payoff is higher than my opponent's payoff, I do not care about the absolute value of mypayoff, even when the difference between my payoff and my opponent's is small).

6

5766

8
9

7345
8271

7

6478

8
8
8

7345
7340
7340

8

6751

7

6526

8

7345

(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?

8

7345

8

7340

I should consult with my opponent if possible. If not, I should try to maximize my own payoff,regardless of my opponent's payoff. This is because there are many people to play and so there islittle overall effect even if I reduce my opponent's payoff. Further, making my opponent's payoffsmall does not lead to my benefit.

8
6
8

7340
5681
7340

(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

60

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
My opponents tended to reduce their opponent's payoff although their own payoff was slightly
smaller than the maximum. First, I simply tried to maximize my own payoff. Later, in rivalry with
my opponents, I also attempted to reduce their payoffs although my payoff decreased.

102

ID Number = 15, Male, Earnings = 2493yen.

ID Number = 15, Male, Earnings = 2493 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)8
By choosing this number, I could receive a reasonable
116446
payoff, no matter whether my opponent chooses a large
investment number or a small investment number.
10
I expected that my opponent's investment number
32356
would be smaller than that at the previous period.
5
I expected that my opponent would choose a large
0870
number.
8
The same as period 1.
52942

The Actual Experiment
Period 1
6
I expected that my opponent would choose at least 11.
Period 2
8
I expected that my opponent would choose a number
between 6 and 8.
Period 3
8
I chose a safe investment number. The same as theabove.
Period 4
7
I expected that my opponent would choose 9 or 10.
Period 5
7
I expected that my opponent would choose 9 or 10.
Period 6
6
I expected that my opponent would choose at least 11.
Period 7
8
I expected that my opponent would choose a number
between 6 and 8.
Period 8
8
The same as the above.
Period 98
The same as the above.
Period 10
9
I expected that my opponent would choose 4 or 5.
Period 11
8
I expected that my opponent would choose a number
between 6 and 8.
Period 12
7
I expected that my opponent would choose 9 or 10.
Period 13
7
The same as the above.
Period 14
7
The same as the above.
Period 15
6
I expected that my opponent would choose at least 11.

9
8

8209
7345

6

5766

8
7
8
5

7340
6478
7237
5064

8
3
4
8

7345
3831
4488
7345

8
8
8
8

7340
7340
7340
7237

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
First I looked at Table 3. Then I used Table 1 to decide my investment number, by checking myinvestment number maximizing my payoff for each investment number of my opponent.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

60

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
At early periods my opponents' investment numbers scattered, but at later periods they converged
to 8. I thought I should also choose the safe number 8 constantly, but I chose slightly different
numbers 6 and 7 at some periods.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
The best choice would be to invest 8 constantly. For investing 8 maximizes my payoff if my
opponent invests 6-8, and it would not cause a big loss even if my opponent chooses a different
investment number. Moreover, my opponent would have the same idea, and so both I and my
opponent would choose 8.

103

104

ID Number = 16, Male, Earnings = 2462yen.

ID Number = 16, Male, Earnings = 2462 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
7
Because I expected that my opponent would choose a84368
middle investment number (around 12) at the first time.
12
Because I expected that my opponent would choose a2415236
small investment number in an attempt to receive a large
payoff.
12
The same as the above.
42700
5Because I expected that my opponent might choose a
2423315
large investment number for safety.

The Actual Experiment
Period 1
9
I expected that my opponent would choose a small
investment number in an attempt to receive a large
payoff at early periods, and I chose a safe number.
Period 2
9
The same as the above.
Period 3
9
The same as the above.
Period 4
7
The same as the above.
Period 5
9
I expected that my opponent would choose a small
investment number in an attempt to receive a large
payoff at early periods.
Period 6
9
I still expected that my opponent would choose a small
investment number in an attempt to receive a large
payoff. This trend seems to continue.
Period 7
6
My opponent would choose a middle investment
number in an attempt to receive a reasonable payoffsafely. Such a trend emerged.
Period 8
6
The same as the above.
Period 9
7
The same as the above.
Period 10
7
The same as the above.
Period 11
6
Because I expected that my opponent would safely
choose a middle investment number.
Period 12
6
The same as the above.
Period 13
7
The same as the above.
Period 14
7
The same as the above.
Period 15
5
The same as the above.

6

5765

8
8
5
6

7250
7250
4950
5765

12

10877

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
I mainly used Tables 1 and 2 among the three tables. I understood the trend roughly from Table 2.
In Table 1, I put a mark on the investment number maximizing my payoff for each investment
number of my opponent.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

65

) % of expectations came true.

8

7237

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?

8
5
7
7

7237
4950
6478
6339

8
3
8
7

7237
3675
7340
6115

Some people tried to get a large payoff by investing a small amount. But most people made steadyinvestment decisions. I attempted to make my payoff as large as possible, considering their
behavior. However, I always cared about my opponent's payoff, and I was mortified when my
opponent's payoff was larger than mine. Nevertheless, I simply accepted the situation, because I
could not decide my opponent's number and only thing I could do was to choose the number tomaximize my payoff even when my opponent wrote a small number.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
My opponent would make a steady investment decision because he must know that investing alarge amount, say 24, is not profitable. Therefore, the best choice would be to invest 6-9. In fact, I
did so because I realized from the payoff tables that I could not get a large payoff anyhow.

105

106

ID Number = 17, Male, Earnings = 2500yen

ID Number = 17, Male, Earnings = 2500 yen

Practice(1) Did you understand the rules of the experiment?

Period 1

Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
7
I expected that my opponent would choose a middle
116432
number between 10 and 12 at the first time. With thisexpectation, I chose 7 among the numbers leading large
payoffs, 7-9.
7
I still expected that my opponent would choose a middle
9
5000
number.
4
I did a risky attempt. My opponent might choose at least
12
6785
13.
8
Because my opponents seems to like a middle number.
105737

The Actual Experiment
Period 1
6
My opponent will certainly choose a number between 10
and 12 at the first period of the actual experiment.
Period 2
7
My opponent would choose a number less than or equal
to 10.
Period 3
7
My opponent would choose a number less than or equal
to 10. Perhaps 8.
Period 4
7
My opponent will certainly choose 8.
Period 5
7
My opponent will surely choose 8.
Period 6
7
I still expected that my opponent chooses 8.
Period 7
7
The same as the above.
Period 87
The choice of my opponent in the previous period was
unusual. After all, 8.
Period 97
I considered 8 only.
Period 10
8My opponent would choose 8. I chose a different
number 8 because my opponent would not choose 9 or
more.
Period 11
8
The same as the above.
Period 12
8
It seems that choosing 8 prevails.
Period 13
8
Choosing 8 maximizes my profit even if my opponent
chooses a number between 4 and 7.
Period 14
8
The same as the above.
Period 15
8
The same as the above.

107

8

7237

8

7340

8

7340

8
7
8
3
8

7340
6478
7340
3675
7340

6
6

5681
5766

8
5
8

7345
5064
7345

8
8

7345
7345

2. I have understood the rules from a middle of the experiment:
From period ( 1) in Practice(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
I referred to Table 2 mainly.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

80

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
There were some silly persons who invested 3-6. I ignored them. In the early stage, my opponents
chose 10-12 steadily, but their investment numbers have gradually converged to 8. I expected themand so I received large payoffs overall. In the later stage, some persons invested small units. I did
not get it. We just lose each other.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
The best choice is to invest 8, because my opponent will choose 8 only.

108

ID Number = 18, Male, Earnings = 2574yen.

ID Number = 18, Male, Earnings = 2574 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3
Period 4YourYour The Reasons for Your Decision on Your Investment Number
Opponent's Your
Invest- (Please specify your expectation on your opponent's
Investment Payoff
ment investment number and the reasons why you chose your
NumberNumber investment number.)2
By choosing this number, my opponent would not receive a
93675
good payoff, no matter whether his investment number is
low or high.
13
I expected that my opponent would choose a large number
94383
at period 2.
0
By choosing this number, I would get a reasonable payoff,
51097
independent of my opponent' number.
7
I expected that my opponent would choose 12. Choosing
84368
this number maximizes my payoff if he chooses 12.

The Actual Experiment
Period 1
8
I expected that my opponent's investment number would be
7 or 8. Choosing 8 makes my payoff high under that
expectation.
Period 2
8
The same as the above.
Period 3
7
I expected that my opponent might unreasonably choose 9
or 10 at period 3.
Period 4
7
My expectation at the previous period proved wrong. But I
still believed my opponent would choose 9 or 10 at thisperiod.
Period 5
8
Because I expected that my opponent would choose 7 or 8.
Period 6
8
After finishing five periods, I expected the probability thatmy opponent chooses 7 or 8 was high.
Period 7
7
I expected that my opponent would choose 9 or 10 this time.
Period 8
8
I expected that my opponent would choose 7 or 8 with highprobability.
Period 9
7
I expected that my opponent might choose 9 or 10
unreasonably.
Period 10
7
I expected that my opponent might choose 9 or 10 this time,
although my expectation at the previous period proved
wrong.
Period 11
7
So far, choosing a number less than 7 has hardly been
observed, while choosing 7 and 8 have frequently been
observed. I expected a number larger or equal to 7.
Period 12
7
Because my expectation at the last period was right, I
expected that my opponent would choose a number larger
than or equal to 7.
Period 13
7
I was confident that my opponent would choose a number
larger than or equal to 7, because my expectations on thelast four periods were right.
Period 14
7
Because I was still confident that my opponent would
choose a number larger than or equal to 7, although myexpectation at the last period proved wrong.
Period 15
7
Because I was confident that my opponent would choose anumber larger than or equal to 7, because of my previous
successes of choosing 7.

109

9

8225

7
8

6526
7340

3

3675

8
7

7345
6526

12
3

11480
3831

8

7340

7

6478

8

7340

7

6478

6

5681

8

7340

8

7340

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
I used Tables 1 and 3 to analyze payoffs. For Table 2, I thought that the number of payoff values
taken for one average value is too many.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

80

) % of expectations came true.

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
Most of my opponent chose at least 7 (most often, 7 or 8). I considered which number leads to ahigh payoff when my opponent chooses 7 or 8, and I also decided to choose 7 or 8.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
It is important to expect which numbers most people would choose and consider which investment
number among those numbers is most beneficial to me. I think investment with low risk and low
return would be best. Because it could happen that for investment with high risk, my payoff may
be relatively low, while my opponent may be relatively large.

110

ID Number = 19, Male, Earnings = 2495yen.
PracticeYour The Reasons for Your Decision on Your Investment Number
Your
Invest- (Please specify your expectation on your opponent's
Opponent's Your
ment investment number and the reasons why you chose yourInvestment Payoff
Number investment number.)NumberPeriod 1
11
I expected that the upper limit of my opponent's investment
7
3918
number would be 15 and the lower limit be 0. I chose thisnumber to get a reasonable payoff under that expectation.
Period 2
6
By choosing this number, I would get a high payoff if my
105561
opponent's investment number is 0 and 15.
Period 3
6
The same as the above.
94850
Period 4
9
I had been concerned only with my payoff, but not my
84512
opponent's. By choosing this number, my opponent would
also receive a high payoff.
The Actual Experiment
Period 1
8
I expected that my opponent's number would be between 687345
and 8 because my opponent would not choose a number
beneficial to me. I chose 8 to maximize my payoff under
this expectation.
87056
Period 2
10
I expected that my opponent's number would be between 8
and 10, because my opponent would care about his own
payoff as well as my payoff and he would ensure around7000 payoff by choosing such a number. I chose thisnumber to maximize my payoff under this expectation.
Period 3
9
My opponent would choose a number such that both he and76481
I can get reasonable payoffs.
Period 4
8
The same as in period 1. I would get a high payoff if my
87345
opponent chose a larger number.
Period 5
8
Initially I planed to do a risky attempt to confuse the87345
market, but I chose a safe number after all.
Period 6
12
I expected that my opponent would choose 8. Because I am
97007
happy that my payoff is around 6000, I attempted toactivate the market.
Period 7
12
The same as the above.
6
5249
Period 83
I want to increase my payoff, but it is better to86383
choose a small number to confuse the market.
Period 94
I tried to confuse the market again, but I also want to8
6751
receive a higher payoff. Hopefully my opponent would
choose at least 8.
Period 10
4
The same the above. I should use this strategy from an
97779
earlier period. I want to make my opponent suffering a loss
for the time being.
Period 11
4
The same as the above.
3
2902
Period 12
5
I would like to receive a reasonable payoff safely. My
87038
opponent would not choose a large number.
Period 13
8
It is meaningless to make my opponent suffering a loss at
87345
these later periods. I have contended with the persons who
have received high payoffs with large investment numbers.
But I cannot predict their behavior.
Period 14
8
I should choose 8 when my opponent chooses the average
76526
number 8.
Period 15
6
I looked for a possibility of getting a high payoff, and87237
wanted to keep my payoff at least 7000 level.

111

ID Number = 19, Male, Earnings = 2495 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
I almost always used Table 1 and I referred to 2 and 3 little. But I sometimes lay Table 3 upon Table
1 when I looked at Table 1.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
6. Others (please specify).
5 ® 3 ® 4 ® 1.
(5. If my payoff is the same as my opponent's payoff, I do not care about the absolute value of mypayoff. ® 2. If my payoff is higher than my opponent's payoff, I do not care about the absolutevalue of my payoff, even when the difference between my payoff and my opponent's is small. ® 3.
It is desirable that both my payoff and my opponent's payoff are as high as possible. ® 4. If I canmake my opponent's payoff as small as possible, it is fine that my payoff is moderate.)(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. ( 50) % of expectations came true.
(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?
Everybody understood well that he gets the highest payoff when his opponent chooses 6-8, and hebehaved based on it. But I always considered that my earnings is 3000 yen when my average payoff
is 8000, and that even when my payoff decreases by 30 points, my actual earnings decreases only by
30 ´ 0.25 yen and it is not a big deal. So I changed my strategy to make my opponent's payoff low
and get the level of 7,000 points. However, I was very disappointed when I invested 4 and my
opponent invested 3. The largest investment number of my opponent is 9. After all, none would
take behavior for mutual benefit. In the later stage, I chose small numbers with the hope thatsomebody might take such behavior.
(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
It is good to invest a large amount, say 15 or 20, boldly at practice. Or it is also good to choose 12 at
all practice periods. This might lead to emergence of persons who considers mutual benefit in thelater stage of the actual experiment. Then choosing 6 or 8 would result in a large payoff. At thefirst few rounds of the actual experiment, choose 10 in an attempt to receive the level of 7000 points.
After that, choose 6-8 basically, but sometime 3 or 4. Is it good? Or is it good to choose 6-8
continuously?

112

ID Number = 20, Female, Earnings = 2523yen.

ID Number = 20, Female, Earnings = 2523 yen.

Practice(1) Did you understand the rules of the experiment?

Period 1
Period 2
Period 3

Period 4YourYour The Reasons for Your Decision on Your Investment
Opponent's Your
Invest- Number (Please specify your expectation on yourment opponent's investment number and the reasons why you Investment Payoff
NumberNumber chose your investment number.)
10
Because I expected that my opponent would choose an84481
investment number between 10 and 12.
9
I expected that my opponent would choose an24
19506
investment number between 7 and 9.
9
By choosing this number, I can guarantee a reasonable
84512
payoff, regardless of my opponent's investment number.
Thinking a similar way, my opponent would also choose
an investment number between 7 and 9.
9
My opponent would not choose a larger number and
105707
take a safe strategy.

The Actual Experiment
Period 1
8
I expected that my opponent would also choose aninvestment number between 7 and 9. None would
choose a large number (19-24) nor a small number (0-3).
Period 2
8
I expected that my opponent would choose aninvestment number between 7 and 10.
Period 3
7
By choosing this number, I can receive a reasonablepayoff even when my opponent chooses a small number.
Period 4
8
I expected that my opponent would choose aninvestment number around 7.
Period 5
7
The same as the above.
Period 6
8
I expected that my opponent's investment number
would almost be 7 or 8.
Period 7
7
I expected that my opponent's investment number
would be 7 or 8. I chose a similar number.
Period 8
8
I expected that my opponent's investment number
would be 7 or 8.
Period 98
The same as the above.
Period 10
8
The same as the above.
Period 11
8
The same as the above.
Period 12
8
The same as the above.
Period 13
8
I expected that my opponent's investment number
would be 7 or 8. By choosing this number, I can receivea reasonable payoff even when my opponent chooses asmaller number.
Period 14
8
I expected that my opponent's investment number
would be 7 or 8.
Period 15
8
The same as the above.

113

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three payoff tables? Which tables did you take a look at when
you decided your investment number?
First, by Payoff Table 2, I got a rough idea of which number would be best. Then, by Payoff Table 1,
I carefully compared payoff values and decided my investment number.
(4) This question is to ask your investment behavior. Which of the following is closest to your wayof thinking on investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.

7

6526

5

5064

9

8271

10

9168

8
6

7340
5766

(7) Did you notice anything about your opponents' investment numbers? How did you behave in
response to them?

7

6478

7

6526

8
8
8
6
8

7345
7345
7345
5766
7345

I thought that my opponent did not try to make my payoff as small as possible. Rather, my
opponent seemed to attempt to get a reasonable payoff even if his payoff was similar to mine.
Therefore, I also chose the same investment number as the expected number my opponent would
choose. Moreover, none choose a large investment number, say 24, nor a very small investment
number because they are not profitable at all.

7

6526

3

3831

(5) What did you think about your opponent's investment?
1. I always expected how much my opponent invests.
(6) This is the question for the one who chose 1. in (5). How often did your expectations come true?
2. (

80

) % of expectations came true.

(8) Finally, What would be the best choice for your investment? What do you think from yourexperience in the experiment? Why?
It is steady and good to make an investment decision so as to receive a reasonable payoff constantly,
regardless of my opponent's investment number. In deciding my investment number, I should not
expect the investment numbers that my opponent would hardly choose, even if my payoff might belarge when he happens to choose them. It is not exciting, but I do not like to go on a gamble
because I know others have similar ideas. I do not think it is a good choice to make my opponent's
payoff small, because my opponent loses only once and my payoff does not become large.
Moreover, I need to expect carefully how my opponent behaves when deciding an investment
number.

114

4. Data for the Tsukuba B Session (with the "Opponent" Wording)
4.1. Pairs of Subjects (ID Numbers) in the Tsukuba B Session: the Same as the Tsukuba A Session (see Table 3.1.).
4.2. Participation Decisions of Each Subject in the Tsukuba B Session: 1 = Participate, O = Not Participate
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12

1

Period 13
Period 14
Period 15

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

0
0
1
1
1
0
1
1
1
1
1
1

1
1
1
0
1
1
0
1
1
1
1
1

1
0
1
1
0
1
1
1
0
1
1
1

0
0
0
1
0
1
1
0
0
0
1
1

0
0
1
1
0
1
1
0
1
1
1
1

0
1
1
1
1
1
1
1
1
1
1
1

0
1
1
0
1
1
1
0
1
1
1
1

0
0
1
1
0
0
1
1
1
1
1
1

0
1
1
1
1
1
1
1
1
1
1
1

1
1
0
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
0
1
1
1
1

0
0
0
0
0
1
1
0
1
1
1
1

1
1
0
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1

0
1
1
1
1
1
1
0
0
1
1
1

0
1
0
0
0
1
1
0
1
0
0
1

0
0
0
1
1
1
1
1
0
1
1
1

0
0
0
0
1
1
0
0
0
1
0
0

1
0
1

1
1
0

1
1
1

1
1
1

0
1
0

1
1
1

1
1
1

1
1
1

1
1
1

1
1
1

1
1
1

1
1
1

1
0
1

1
1
1

1
1
1

1
1
1

1
1
1

0
1
1

1
1
1

0
0
0

4.3. Participation Decisions of Each Subject's Opponents in the Tsukuba B Session: 1 = Participate, O = Not Participate
ID #

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Period 1
Period 2
Period 3
Period 4
Period 5

0
0
0
1
1

1
0
0
1
1

0
1
1
1
1

0
1
1
0
1

0
0
0
0
0

0
0
0
1
1

0
0
1
0
1

0
1
1
1
0

1
0
1
1
0

1
0
1
1
0

0
1
1
0
1

0
1
1
1
1

0
1
1
1
1

0
1
1
1
0

1
0
1
1
1

1
1
0
1
1

0
1
1
1
1

1
1
1
0
0

1
1
0
1
1

1
1
0
1
1

Period 6

0

1

1

1

1

1

1

0

1

1

1

1

1

1

1

1

1

1

1

1

Period 7
Period 8
Period 9

1
1
1

1
1
0

0
1
0

0
0
1

1
0
0

1
1
1

1
1
1

1
1
1

1
1
1

1
1
1

1
0
1

1
1
1

1
0
1

1
0
1

1
1
1

1
1
1

1
0
1

1
1
0

1
0
0

1
0
1

Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1
1
1
1
1
1

1
1
1
1
1
1

1
1
1
0
1
0

1
1
1
1
1
1

1
1
1
0
1
1

1
0
1
1
0
0

1
1
1
1
1
0

1
0
1
1
1
1

1
1
1
1
1
1

1
1
1
1
1
1

0
1
1
1
1
1

1
1
1
1
1
1

1
1
1
1
1
1

1
1
1
1
1
1

1
1
1
1
1
1

0
1
0
1
1
1

1
1
1
1
1
1

1
1
1
0
0
1

1
1
1
1
0
1

1
1
1
1
1
1

115

4.4. Investment Numbers of Each Subject in the Tsukuba B Session (blank means non-participation).
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12

1

2

8
6
8

9
7
6
7
6

8
8

8

5

6

7
7

11
7
11

6
7

7
7
7

8
8

7
7
7
7

10
7
7

8
8
8

8
6
8
8
9

8

4

7

8

9

10

7

8
8

7
4
8
7
3
8

Period 13
Period 14
Period 15

3

8
9
11

7

0
0
11
8
11
8
11
11
11
0
8

11
6

6
6
6
7

9
8
8
9
7
6

7
7
8
7
8
5
8
7
7
7
7

11
9
8

7
7
11

7
7
9

7
7
7

8
6

6
6
7

11

7
11
7
8
7
7
7
7
7
7
7

7
8
7
7
8
8
8
7
8
7
8
8

7
7
8

8
8
8

12
13
14
15
16
17
18
19
20
11 11
7
8
7
6
11
7
6
0
6
7
8
6
6
7
7
8
6
6
6
8
7
8
9
6
8
6
8
8
7
8
8
9
7
6
8
8
9
7
7
7
7
8
8
7
8
11
8
8
8
5
8
11
8
8
6
7
7
6
8
7
8
8
8
7
8
8
8
8
8
8
7
7
8
7
8
8
8
8

8

8
8
8

8

7
7
7

8
7
7

8
6
6

8
8
8

11
7

4.5. Investment numbers of Each Subject's Opponents in the Tsukuba B Session (blank means non-participation).
ID #Period 1
Period 2
Period 3
Period 4
Period 5

1

2

3

4

5

6

7

8

9

7

7
8

Period 6

0
8

11
8

11
6
6
8

8

8

6

Period 7
Period 8
Period 9

8
8
8

7
8

Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

6
8
7
8
8
8

8
7
7
8
6
8

10

7
7

14

8
7

0
7

7
6
6
6

11
0
7

8

6
8
7
8

7

8

6

11

6

7

6

8

7
8
8

7
7
5

7
7
8

7
4
8

9
8
8

8

8

8

7
11
7

7

7
8
8

7

9
8
7
8
8

6

11
8
6
8
7
7

7
8
7
8
7
6

7
8
8
7
7

7
8
7
8
7
7

8
3
8
7
9
8

8
7

8
8

7
7
8
8

15

16

8

8

11

7

13

8

7

7
7
8
8
7
8

7
8

12

6
6

7
8
8
8

9
6
6

11

8

17

7
6

18

19

11
8
11

11
11

20

7
7

11
8

7
6

7
7
9

8
8

7
9
6
7

8

6

7

9

8

8

7

7

9
8
11

7

8
11

7

11

8

5
6
6

7
8
7
7
7
8

8
8
9
7
8
8

7
7
8

7
6
8
8

7

9

116

7
7
7
8

7
7
7
8
11
8
8

6
6
0
7
10
11
11

4.6. Pairs of Investment Numbers in the Tsukuba B Session (blank means non-participation and boldfaced numbers indicate data ofsubjects who did spiteful behavior).
Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #
1,6
1,5
1,10
1,3
6
7 1,16
8
8 1,8
1,12
7
8 1,9
4
8
8
2,10
8
7 2,8
2,18 112,4
11 2,118
8 2,14
8
8 2,3
8
8
9
7 2,163,93,7
11 3,179
6 5,203,10
6
8 4,20 11
3,15
6
7
7
7
8 3,13
4,8
4,6
6 4,9
7
6 5,197
8 4,140 4,16
8 6,19 11
7 4,12
5,7
9,20
5,15
7,18
5,8
5,11
6
8 6,188
7 5,137
7
11,20
10,19 11
6,14
8,17
6
6 6,7
8
6 6,10 11
7 7,177
7 6,12 118
7
0
12,19 1111,18
8
6
7 9,168
8 12,206
8 7,9
6
8 8,169
7 7,11
0 7,13
7
13,18 1112,17
7
6 8,128
6 10,157
7 13,198
6 15,207
6 9,15
7 8,10
8
7
5
14,17
13,16
6
7 9,11
7
7 11,14
14,18
16,19
8
7 10,147
9 17,20
715,16
7
8 14,15
11 19,20
12,13
6
7 15,177
9 17,188
9 11,138
8 18,19
11
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #1,11
8
8 1,177
6 1,13
3
8 1,188
7 1,2
8
8 1,19
8
8
8 1,4
2,20
2,13
8
8 2,5
8
7 2,159
7 3,20 10
2,17
8
6 2,6
6
8
3,19
3,12
7
8 3,4
7
8 3,147
8 4,198
8 3,16
7
7 3,5
7
4,18
11 4,114,13
8
8 5,184,15
8
7 7,20 11
7 6,20
0
5,17
5,10
7
7 7,196
8 5,12
8 6,17 11
8 5,14
8 8,1998
7
7
76,16 11
8 6,9 116,118
8 7,167
8 6,139,18
7
7 8,18
7
9
7
7,15
6
5 7,8
6
9 9,17
8 7,107
7 8,157
7 7,127
8 10,17
8
6
7
8,14
8
8 14,20
6
7 10,167
8 8,9
6
8 8,117
8 11,168
7
7 9,14
79,13
7
8 15,197
8 11,158
7 16,2010,13
7
8 9,10
7 12,15
8
7
7
7
10,12
7
8 16,1812,14
8
8 17,198
8 11,128
8 18,20 11
13,14
8
8
7

117

4.7. Payoffs of Each Subject in the Tsukuba B Session
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1
706
706
2386
6339
7345
706
7340
6751
7345
5681
6383
6526
7345
4904
7345

2
6526
2523
2658
8278
7345
7345
4018
7345
2003
7345
6526
6481
7345
5766
4904

3
2210
8278
5765
5681
4904
7237
2210
6339
706
7340
7340
7340
2615
6478
2210

4
706
706
4904
2658
4018
5681
2658
706
8278
4018
6526
7345
7345
6526
7345

5
706
706
2210
2210
706
7237
7340
706
2210
6478
7340
7340
706
7340
4018

6
706
706
706
5504
5766
6114
6526
6765
6765
6114
706
7345
6765
2523
2386

7
706
2658
6339
706
7237
7237
6478
4018
4762
8209
7237
6478
7340
7340
2658

8
9
10
706 4018 7340
5907 2210 2658
5766 6478 4904
5515 7345 6478
706 2210 2386
706 5766 10339
6481 6115 8271
6526 4420 7340
7345 7340 7340
5765 10339 6478
2210 7340 7340
6339 5681 6478
6478 7340 7340
7340 6478 6478
7250 6478 5766

11
122210 2658
2386 5681
6478 7237
2210 6339
7345 7237
5766 6339
7345 6526
2210 10173
7345 6526
2210 6526
6526 7345
7345 6526
7345 7345
6526 6526
6526 6526

118

13
2658
6339
5681
5681
5766
5766
7345
706
6526
7345
3831
7345
6526
5907
7345

14
706
8278
706
4018
706
7345
6481
706
7345
6339
7345
6526
6526
6526
7345

15
16
17
7340 6526 706
2658 5681 6339
4018 2386 8209
6478 7345 5515
8271 7345 6481
5681 6526 8225
4950 8271 6478
5681 7345 706
5272 10173 4018
7340 2210 6339
7340 6526 6526
8271 2210 7345
6478 6526 10173
7340 6478 7237
7340 7340 7237

18
198278 8278
4904 8278
8278 706
706 10384
706 7237
7250 7340
7340 6526
8278 2658
2658 706
4018 6526
4018 5766
7340 7345
706 7345
2658 2386
6478 8225

20
4018
4018
706
4018
5766
6339
8278
706
3244
5681
706
4018
7031
8278
8278

4.8. Record Sheets and Questionnaires for the Tsukuba B Session
ID Number = 1, Female, Earnings = 2568 yen
Practice 1

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

9

7

Practice 2

You

The Reason for Your Decision on Participation
As a first step I chose participation to look at what would happen.

Your Payoff The Reason for Your Decision on Investment Number
3980

Participation
in investmentO¯

Invest. Num.
Practice 3

5

8

3976

Because I expected that my opponent would choose a large number.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

12

6

3400

Because I expected that my opponent would write a number around 10.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

10

3

Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.

Payoff
Table

Because I expected that my opponent would choose a large investment
number.

Your
OpponentO¯Participation
in investment

You

PayoffTable

The Reason for Your Decision on Participation
Because I expected that a high payoff when choosing participation.

Your Payoff The Reason for Your Decision on Investment Number

Because I can get at least 500 by choosing participation.
Your Payoff The Reason for Your Decision on Investment Number

Because I expected a higher payoff by choosing participation than bychoosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number
2038

Payoff
Table

Because I expected that my opponent's investment number would bearound 7.

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation andan investment number around 11.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation and an
investment number around 11.

Your Payoff The Reason for Your Decision on Investment Number
706

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

Invest. Num.

67

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 6 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

48Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment
¯
¯
8

8

The Reason for Your Decision on Participation
Because my payoff would be higher than 706 by choosing participation.

Your Payoff The Reason for Your Decision on Investment Number
2386

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

119

8

Payoff
Table

PayoffTable

If I choose 8, then my opponent's payoff is 4904 and my payoff is 2386. If
I choose 11, then my opponent's payoff is 8278 and my payoff is 2658.
My payoff changes little, while my opponent's payoff does much.
The Reason for Your Decision on Participation
Because my payoff would certainly be higher than 706 by choosing
participation.

Your Payoff The Reason for Your Decision on Investment Number
6339

Because I expected that my opponent would choose a middle investment
number.

PayoffTable

The Reason for Your Decision on Participation
Because my payoff would be higher than 706 with highprobability.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected that my opponent would choose a number around 6.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would be about to choose
participation and an investment number around 11.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because choosing non-participation is risky.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected that my opponent would invest around 7 units.

PayoffTable

The Reason for Your Decision on Participation
Because choosing non-participation is risky.

Your Payoff The Reason for Your Decision on Investment Number
6751

Because I expected that my opponent would choose a middle investment
number.

PayoffTable

The Reason for Your Decision on Participation
Because both payoffs would be high if both choose participation.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected that my opponent would choose a similar investment
number.

120

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

38

Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

87Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation
Because both payoffs would be high if both choose participation.

Your Payoff The Reason for Your Decision on Investment Number
5681

Because I expected that my opponent would choose a middle number.

PayoffTable

The Reason for Your Decision on Participation
Because it would be more likely to get a high payoff by choosing
participation than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
6383

Because I expected that my opponent would choose an investment
number about 8.

PayoffTable

The Reason for Your Decision on Participation
Because it would be more likely to get a high payoff by choosing
participation than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because I expected that my opponent would choose a similar investment
number.

PayoffTable

The Reason for Your Decision on Participation
Because it would be more likely to get a high payoff by choosing
participation than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected that my opponent would choose a similar investment
number.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would be about to choose
participation and an investment number around 11.

Your Payoff The Reason for Your Decision on Investment Number(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
In particular I looked at Table 1 when I decided my investment number. If someone invests 24 units, he loses heavily, while
his opponent has a big money. I wonder if such a person exists. Because choosing a large number or a small number isrisky, everybody tended to choose about 8.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
It is desirable that my payoff is as high as possible, while my opponent's payoff is as small as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
When I did not participate in investment, I expected my payoff would be high by my opponent's investment. However,
because my opponent had the same idea, we destroyed ourselves. Therefore I tried to avoid non-participation. After all, thepayoffs were often high when both participated in investment.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
At early periods I chose the numbers randomly. But my opponents' investment numbers have been almost fixed from a
middle. Thus I chose numbers leading to high payoffs for those numbers.
When your opponent did not participate in investment:

The Reason for Your Decision on Participation
Because it would be more likely to get a high payoff by choosing
participation than by choosing non-participation.

(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
7345(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.

I chose the number so that only my opponent did not get a large payoff. For example, if I choose the number maximizing
my payoff, then my opponent's payoff is about 8000. On the other hand, if I choose a number (8) so that my payoff is notmuch different from the maximal payoff, then my opponent's payoff is about 5000. Therefore I chose the latter.

4904
PayoffTable

ID Number = 1, Female, Earnings = 2,568 yen

Because I expected that my opponent would choose a similar investment
number.

121

I think the best choice would be to participate in investment and invest about 8 units. This is because both I and my
opponent receive reasonable payoffs.

122

ID Number = 2, Male, Earnings = 2852 yen
Practice 1

Participation
in investment
Invest. Num.

Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment

Invest. Num.
Practice 4

You
O
¯

Your
Opponent
O
¯

12

9

4663

Because I thought that my payoff would be large by choosing thisnumber with high probability, taking account of my opponent's
investment number.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13
You
´
¯

You

Your
OpponentO¯

Invest. Num.

107Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
7Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

9

I expected a higher payoff by choosing participation than bychoosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number
1631

Because my payoff is maximized by choosing this number.

PayoffTable

The Reason for Your Decision on Participation

Because my payoff would be larger when my opponent chooses
participation, but I do not, comparing with the case in which both choose
participation.
Your Payoff The Reason for Your Decision on Investment Number

Payoff
Table

O
¯

8

Your Payoff The Reason for Your Decision on Investment Number

500

Participation
in investment

The Reason for Your Decision on Participation
I expected a reasonable payoff by choosing participation.

0
Your
OpponentO¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.
11
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

The average payoff is higher by choosing participation thanby choosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number
3981

Payoff
Table

There is good probability that my payoff is high by choosing
this number.

The Reason for Your Decision on Participation
I am afraid that my payoff would be low if my opponent chooses nonparticipation.

Your Payoff The Reason for Your Decision on Investment Number
6526

Payoff
Table

Because my opponent also chose participation, I expected to receive areasonable payoff safely and could avoid a big loss by choosing around 8.
The Reason for Your Decision on Participation
I am afraid that my payoff is low (706) if both choose non-participation.

Your Payoff The Reason for Your Decision on Investment Number
2523

Because my opponent did not participate in investment, I reduced his
payoff to the permissible level.

Invest. Num.
88Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.

123

6

PayoffTable

The Reason for Your Decision on Participation
Because I attempted to avoid the situation in which bothchoose non-participation and the payoffs are 706.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff is maximized by choosing this number.

PayoffTable

The Reason for Your Decision on Participation

Because my payoff would be larger when my opponent chooses
participation, but I do not, comparing with the case in which both choose
participation.
Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I would like to avoid the worst situation (neither of us participates ininvestment).

Your Payoff The Reason for Your Decision on Investment Number
7345

Because there is high probability that I steadily obtain a reasonablepayoff.

PayoffTable

The Reason for Your Decision on Participation

My payoff would be large when I do not participate in investment, but
my opponent does. However, when neither of us participates ininvestment my payoff is small. Therefore, I chose participation to receivea reasonable payoff safely.
Your Payoff The Reason for Your Decision on Investment Number
7345
Payoff
Table

Because I could receive a reasonable payoff steadily.
The Reason for Your Decision on Participation
Hopefully my opponent participates in investment.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Choosing participation is safe.

Your Payoff The Reason for Your Decision on Investment Number
7345

By choosing this number, I could ensure a reasonable payoff.

PayoffTable

The Reason for Your Decision on Participation

My opponent would not choose a large investment number even if heparticipates in investment, but I do not. Therefore I expected a large
payoff by choosing participation.
Your Payoff The Reason for Your Decision on Investment Number
2003

I chose the number so that my opponent's payoff was reduced to theextent that the decrease in my payoff is acceptable.

124Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

97

Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.

8

PayoffTable

The Reason for Your Decision on Participation
Because I can expect a reasonable payoff and there is high probability
that my opponent will participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because both payoffs are large even when I consider my opponent's
payoff.

PayoffTable

The Reason for Your Decision on Participation
Because I can expect a reasonable payoff.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because choosing this number is the safest choice.

PayoffTable

The Reason for Your Decision on Participation
I can expect a reasonable payoff.

Your Payoff The Reason for Your Decision on Investment Number
6481

Choosing 9 is not safe as doing 8, but my payoff might be higher and theloss would be small.

PayoffTable

The Reason for Your Decision on Participation
With higher probability I can expect a larger payoff bychoosing participation than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I can steadily receive a reasonable payoff for any investment
number of my opponent.

PayoffTable

The Reason for Your Decision on Participation
Because it is safe.

Your Payoff The Reason for Your Decision on Investment Number
5766

Choosing this number would maximize my payoff when considering my
opponent' behavior.

PayoffTable

The Reason for Your Decision on Participation

From data at the previous periods, there is high probability that my
opponent will participate in investment. If this happens,
I may receive a large payoff by choosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number

ID Number = 2, Male, Earnings = 2,852 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 2) in Practice(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I often used the payoff tables for the case in which both participate in investment. Considering not only my benefit but also
my opponent's behavior carefully, I chose the number maximizing my payoff.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
2. If my payoff is higher than my opponent's payoff, I do not care about the absolute value of my payoff, evenwhen the difference between my payoff and my opponent's is small.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
At first glance I thought non-participation might be more beneficial than participation. However, when I did not participate
in investment, but my opponent did, the number that my opponent chose was smaller than the number maximizing his
payoff. Then my opponent did not lose much, while I lost very much, comparing with the case in which my opponent
chooses the number maximizing his payoff. After all, I could receive a higher payoff by participating in investment. Also, I
would like to avoid the case in which neither of us participates in investment.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
My opponent did not want to lose in his payoff, either. Considering this point, I tried to maximize my payoff.
When your opponent did not participate in investment:
I prevented my opponent from receiving a large payoff, as long as the reduction of my payoff was permissible.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
I think that the total profit would be larger by participating in investment at all periods, because of the reasons mentioned
above.

4904

125

126

ID Number =3 , Male, Earnings = 2530 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

6

12

7172

Because my opponent would not choose a large number at the first time.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

9

6

3491

The same as the above.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

7

11

6432

Because my payoff would be large with high probability.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
2

24

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

9

6

PayoffTable

The Reason for Your Decision on Participation
When participating in investment, I can control my payoff by choosing an
investment number.

Your Payoff The Reason for Your Decision on Investment Number

Because I expected a higher payoff by choosing participation.
Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

Because I am sure that my payoff is low when I do not participate ininvestment.
Your Payoff The Reason for Your Decision on Investment Number
24369

PayoffTable

I expected that my opponent's investment number would bearound 10.

The Reason for Your Decision on Participation
To look at what will happen.

Your Payoff The Reason for Your Decision on Investment Number
2210

Because I did not like that my opponent' payoff was large.

PayoffTable

The Reason for Your Decision on Participation
Because I could ensure at least 7000 payoff by choosing
non-participation.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
Because I did not participate in investment at the last period.

Your Payoff The Reason for Your Decision on Investment Number
5765

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

68Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 9 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

8

PayoffTable

The Reason for Your Decision on Participation
Because I would like to maintain at least 10,000 payoff.

Your Payoff The Reason for Your Decision on Investment Number
5681

My opponent's investment number would be small.

PayoffTable

The Reason for Your Decision on Participation
Because my payoffs were only about 6,000 when I chose participation.

Your Payoff The Reason for Your Decision on Investment Number
4904
PayoffTable

The Reason for Your Decision on Participation
Because of my failure at the last period.

Your Payoff The Reason for Your Decision on Investment Number
7237

Payoff
Table

Because choosing this number would ensure a reasonable payoff on
average.
The Reason for Your Decision on Participation
Because I do not like the situation in which neither of us participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
2210

I considered the balance of my opponent's payoff (and my payoff).

PayoffTable

The Reason for Your Decision on Participation
The same as the last period.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as period 6.

PayoffTable

The Reason for Your Decision on Participation
To look at what will happen.

Your Payoff The Reason for Your Decision on Invest. Num.
706
PayoffTable

The Reason for Your Decision on Participation
Because of my failure at the last period.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected that my opponent's investment number would be between 6
and 8.

Because I expected that my opponent would invest about 10 units.

127

128

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

10

Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

PayoffTable

The Reason for Your Decision on Participation
Participation is less risky than non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the previous period.

PayoffTable

The Reason for Your Decision on Participation
Because I can get a reasonable payoff constantly by participation.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected that my opponent would choose 8.

PayoffTable

The Reason for Your Decision on Participation
I attempted to avoid the situation in which neither of us
participates in investment.

Your Payoff The Reason for Your Decision on Investment Number
2615

PayoffTable

I tried to get a large payoff and I also considered my opponent's
payoff.
The Reason for Your Decision on Participation
The same as the previous period.

Your Payoff The Reason for Your Decision on Investment Number
6478

I expected that my opponent would choose 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the pervious period. My payoff would be 6000-7000.

Your Payoff The Reason for Your Decision on Investment Number
2210

I made my opponent' payoff not large.

ID Number =3 , Male, Earnings = 2,530 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
My payoff is quite low when my opponent does not participate in investment.
I almost always used Payoff Table 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
4. If I can make my opponent's payoff as small as possible, it is fine that my payoff is moderate.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
At early periods, I expected that if I did not participate in investment, my opponent would invest 10 or 11 units to maximize
his payoff, and thus my payoff would be 7000 or 8000. However, my actual payoffs were lower than these expected value,
because my opponents chose smaller numbers. Or my payoff was 706 because my opponent did not participate ininvestment, either. Therefore I usually participated in investment at later periods.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I chose 7 because my payoff would be reasonable on average and my opponent's payoff would not be very high.
When your opponent did not participate in investment:
I chose 7 to make my opponent's payoff small.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
My opponents did not choose large investment numbers, neither did I. This is because they did not like that the payoff of
their opponent was higher than their own payoff. Most people invested 7 or 8 units. But by investing 7 or 8 units, I had
damage because my opponents did not participate in investment often. I think that investing 7 or 8 units is good when my
opponent participates in investment.

129

130

ID Number = 4, Male, Earnings = 2291 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

7

12

7234

Expecting my opponent would choose 12 or 13.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation´¯Your Payoff The Reason for Your Decision on Investment Number

Expecting many people would choose participation.
Your Payoff The Reason for Your Decision on Investment Number
6117
Payoff
Table

O
¯

Your
Opponent
O
¯

13

9

4383

You

Your
Opponent´¯

Payoff
Table

You

O
¯
13

Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
8The Reason for Your Decision on Participation
As a first step I chose participation.

13

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
Because I did not participate in investment at the last period.

Your Payoff The Reason for Your Decision on Investment Number

The Reason for Your Decision on Participation
Because of my success at period 1. I did the same thing.

Your Payoff The Reason for Your Decision on Investment Number
1631

My payoff is maximized by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
Because my payoff would be 8278 if my opponent participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I tried non-participation one more time.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

PayoffTable

The Reason for Your Decision on Participation
Because of my failures at periods 1-3.

Your Payoff The Reason for Your Decision on Investment Number
2658

My payoff is largest by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
Because of my failure in period 4.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Because non-participation did not work well.

Your Payoff The Reason for Your Decision on Investment Number
5681

Because I expected that my opponent would choose 8-11.

PayoffTable

The Reason for Your Decision on Participation
Because participation worked better than non-participation did.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff is largest by choosing this number.

PayoffTable

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
Because non-participation went well at period 9.

Your Payoff The Reason for Your Decision on Investment Number
4018

Your Payoff The Reason for Your Decision on Invest. Num.
4904

131

132

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation

Because my opponent did not choose 11 in the case ´ O (in which I did
not participate in investment, but my opponent does).
Your Payoff The Reason for Your Decision on Investment Number
6526

Because many people chose 7 or 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

ID Number = 4, Male, Earnings = 2291 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 1) in Practice.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I thought nobody would invest more than 11 units.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
At early periods I expected that if I did not participated in investment, then I could receive high payoffs because my
opponents would invest 11 units. However my opponents did not do so. Therefore I have participated in investment from a
middle.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
Because many people chose 7 or 8, I chose a number in an attempt to make my payoff as large as possible for such a number.
When your opponent did not participate in investment:
I chose the number maximizing my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Participate in investment at all periods. Choose 7 or 8 when the opponent participates in investment, and choose 11 when hedoes not.

133

134

ID Number =5 , Male, Earnings = 1889 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

Your
Opponent
O
¯

8

14

8885

I expected that my opponent would invest about 10 units, and chose theinvestment number maximizing my payoff under that expectation.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

7

10

Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You
´
¯

You
´
¯

Invest. Num.

Your
OpponentO¯

Your Payoff The Reason for Your Decision on Investment Number

Because I wanted to know what my opponent would do one more time.
Your Payoff The Reason for Your Decision on Investment Number
5688

Payoff
Table

Because my payoff would be at least 5000 if my opponent invests at least
9 units.
The Reason for Your Decision on Participation
Because I expected that my opponent would choose "participation" andwanted to get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
2299

Because I expected that my opponent would invest 13 units.

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

13

Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
7The Reason for Your Decision on Participation
Because I wanted to know what my opponent would do.

8

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.

PayoffTable

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
6117

Because I expected that my opponent would invest 10-13 units.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would choose participation, and I
wanted to get a reasonable payoff safely at the first period.

Your Payoff The Reason for Your Decision on Investment Number
706

I made a wrong estimate.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would choose participation thistime, and I wanted to get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
706

I made a wrong estimate again.

PayoffTable

The Reason for Your Decision on Participation
Because of my failures at the previous two periods. I tried to recover myloss.

Your Payoff The Reason for Your Decision on Investment Number
2210

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Period 5 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to get a reasonable payoff this time.

Your Payoff The Reason for Your Decision on Investment Number
2210

My opponent expected that I would invest 11 units. Instead, I reduced
my opponent's payoff half by choosing this number.

PayoffTable

The Reason for Your Decision on Participation

My opponents at the previous four periods chose "non-participation,"and so my opponent at this period would
choose "participation."Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because my payoff is only 706 if neither of us participates in investment.

Your Payoff The Reason for Your Decision on Investment Number
7237

Because I expected that my opponent would invest 10 or 11 units.

PayoffTable

The Reason for Your Decision on Participation
Because I have to participate in investment once more, in order to recover
my loss.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected that my opponent would invest 9 or 10 units.

PayoffTable

The Reason for Your Decision on Participation
Because all would feel that participation is moreadvantageous, I counterplotted their plans.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I expected my payoff would be larger by choosing participation
than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
2210

My opponent expected that I would invest 11 units. Instead, I reduced
my opponent's payoff half by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
Because I expected my payoff would be larger by choosing participation
than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
6478

Because I expected my opponent would invest 9 or 10 units.

My opponent expected that I would invest 11 units. Instead, I reduced
my opponent's payoff half by choosing this number.

135

136

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

78

Period 13 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

PayoffTable

The Reason for Your Decision on Participation
Because I expected my payoff would be larger by choosing participation
than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected my opponent would invest 9 units.

PayoffTable

The Reason for Your Decision on Participation
Because I expected my payoff would be larger by choosing participation
than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because my opponent would invest at most 8 units, I wanted
to get a higher payoff than my opponent does.

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to get a little higher payoff.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

ID Number =5 , Male, Earnings = 1889 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 3) in Actual Experiment(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I thought none would invest more than 12 units as soon as I looked at Payoff Table 1. Payoff tables 2 and 3 were notnecessary for me. I realized that investing 8 units would be best to receive the maximal payoff. By using Payoff Table 1, I
considered which investment number maximize my payoff for each investment number of my opponent, and I realized thatthe best choice is to invest 8 units.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

The Reason for Your Decision on Participation
I wanted to avoid the situation in which neither of us participates ininvestment and the payoff is 706.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected my opponent would invest 7 or 8 units.

PayoffTable

The Reason for Your Decision on Participation
I went on the gamble because this is the final period.

Your Payoff The Reason for Your Decision on Investment Number
4018

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Basically, participation in investment is less risky and safe. However, when I expect my opponent to participate ininvestment, non-participation in investment is more beneficial theoretically.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I invested 7 units because I expected that my opponent would invest 8 units. By investing 7 units instead of 8 units, mypayoff decreases only by 5, while my opponent's payoff decreases by at least 800.
When your opponent did not participate in investment:
Clearly my opponent intended to receive 8278 payoff, expecting that I would invest 11 units. I was angry about it.
Therefore, I invested 7 units so that my opponent's payoff was about the half of 8278.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
(No answer)

137

138

ID Number = 6, Male, Earnings = 2158 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

You
O
¯

Your
Opponent
O
¯

14

8

3692

Because I like this number.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You

PayoffTable

The Reason for Your Decision on Participation
As a first step I participated in investment to look at what would happen.

Your Payoff The Reason for Your Decision on Investment Number

As a first step I did not participate in investment to look atwhat would happen.
Your Payoff The Reason for Your Decision on Investment Number

13

6117
PayoffTable

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

8

24

20690

Because my opponent's payoff was larger than mine at practice 1.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

24

2

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.
0
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

0

The Reason for Your Decision on Participation
I participated in investment for a trial.

Your Payoff The Reason for Your Decision on Investment Number

I wanted to participate in investment and invest 24 units, because this ispractice.
Your Payoff The Reason for Your Decision on Investment Number
500

PayoffTable

I invested 24 units to make my opponent happy for a moment and shakehim.

The Reason for Your Decision on Participation
Because my opponent would participate in investment perhaps.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation

The payoffs of all subjects would increase by choosing participation,
instead of continuing to choose
non-participation.
Your Payoff The Reason for Your Decision on Investment Number
706

I do not want to lose a game against my opponent. Life is not so easy.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

116Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
117
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
118Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
118Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

11

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5504

My opponent would choose around 8, and I sacrificed my payoff bychoosing 11.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

This number would be the safest one which minimizes myloss.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6114

Choosing 11 would be best if the payoffs of all subjects are considered.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because I expected my opponent would choose 6-8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6765

Choosing 11 would be best if the payoffs of all subjects are considered.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6765

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6114

I have received reasonable payoffs recently, and so it matters little to me
which number should be chosen.

I hate my opponent's attitude. He only considers his own
payoff. Think of the payoffs of others.

139

140

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

0

8

8

Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
118Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Investment
9
NumberPeriod 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Investment
Number

8

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

Payoff
Table

PayoffTable

It would be best to punish my opponent by reducing his payoff even if
my payoff also decreases. Life is not so easy. What did my opponent
think? I prevented him from receiving a high payoff.

(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.

The Reason for Your Decision on Participation(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?

The same as the above.

I looked at Payoff Table 1.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would choose a number around 6-8. Ishould choose 8 to maximize my payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6765

Choosing 11 would be best if the payoffs of all subjects are considered.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Invest. Num.
2523

I chose 9 on sufferance, but I will never choose 11. There are many mean
fellows. I feel sick. I will never descend to such meanness.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Invest. Num.
2386

ID Number = 6, Male, Earnings = 2158 yen

This is the final period. How silly you are! But I never write 24. Feelingsick.

(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
It is desirable that the sum of my payoff and my opponent's payoff is as high as possible, unless my opponent is mean.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
At early periods I cared only about my payoff and did not participate in investment. But the others did not, either. Because
non-participation was not beneficial as a whole, I decided to participate in investment.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I considered the sum of my payoff and my opponent's payoff. Perhaps my opponent would choose around 6, 7, or 8, and so
I chose around 11.
When your opponent did not participate in investment:
I invested 0 units so that both payoffs were 706. I was very angry about my opponent because he cared only about his own
payoff. But at later periods I invested some units out of pity.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
We should make investment decisions to maximize the sum of my payoff and my opponent's payoff. I am irritated whenmy opponent considers only his own payoff.

141

142

ID Number = 7, Female, Earnings = 2620 yen
Practice 1

Participation
in investment

Investment
NumberPractice 2

Participation
in investment
Investment
NumberPractice 3

Participation
in investment
Invest. Num.
Practice 4

You
O
¯

12

You

Your
OpponentO¯

7

The Reason for Your Decision on Participation

Because my opponent would not participate in investment to see what
happens or he would invest a small amount at thefirst time.
Your Payoff The Reason for Your Decision on Invest. Num.
3792

O
¯
3

9

4039

Because my opponent would invest a relatively large amount.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

6

12

You

Participation
in investmentO¯

Invest. Num.

7

10Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
11

Payoff
Table

Because my opponent would invest a small amount to look at what
would happen.

Your
OpponentO¯

Your
OpponentO¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
If I do not participate in investment, but my opponent does, my opponent
would definitely choose 13.

Your Payoff The Reason for Your Decision on Invest. Num.

My payoff would be limited to some degree if I do not participate ininvestment.
Your Payoff The Reason for Your Decision on Investment Number
7172

PayoffTable

My opponent would invest 7-9 units of money, and I chose
this number to receive a reasonable payoff safely under that expectation.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5688

Because I expected that my opponent would choose a large investment
number as at practice 3.

PayoffTable

The Reason for Your Decision on Participation

If I do not participate in investment, but my opponent does,
my opponent would invest 11 units of money to maximize his payoff.
(Whether or not my opponent participates in investment is left to chance.)Your Payoff The Reason for Your Decision on Investment Number

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

67

Period 4 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

706
PayoffTable

The Reason for Your Decision on Participation
Because I recognized some persons have the similar idea.

Your Payoff The Reason for Your Decision on Investment Number
2658

I chose the number which maximizes my payoff because I
knew my opponent did not participate in investment.

143

Invest. Num.
7
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

5

PayoffTable

The Reason for Your Decision on Participation

There is good probability that my opponent would choose
non-participation. But I do not like the case in which my
payoff is only 706.
Your Payoff The Reason for Your Decision on Investment Number
6339

Because my opponent would invest a secure number when heparticipates in investment.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that someone would participate in investment toavoid falling together.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
2658 is better than 706.

Your Payoff The Reason for Your Decision on Investment Number
7237

I expected that my opponent would invest 6-9 units.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I would like to have a bet one more time.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Because I perceived that my opponent might be fool (the opponent at thelast period did not choose the number maximizing his own payoff).

Your Payoff The Reason for Your Decision on Investment Number
4762

I expected that my opponent would choose 7-9.

144Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
69Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
77
NumberPeriod 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

PayoffTable

The Reason for Your Decision on Participation
Because of the reasons at periods 5 and 9.

Your Payoff The Reason for Your Decision on Investment Number
8209

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

PayoffTable

The same as the above.

The Reason for Your Decision on Participation
The same as the above.

ID Number = 7, Female, Earnings = 2620 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 2) in Practice(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
By choosing around 7-9, I can constantly get 6,000-7,000 points if my opponent also takes a safe strategy. There would be
little people who invest more than 9 units. All of us would receive similar payoffs if we just understand the rules.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
It is desirable that my payoff is high and the difference between my payoff and my opponent's is large.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:

7340

The same as the above.

If I do not participate in investment, then it is possible that my opponent may not either, and both may get low payoffs.
Also, I expected a high payoff in the case ´O (in which I did not participate in investment, but my opponent did). However,in that case, my payoff was not so high, because my opponent thought that if he could make his opponent's payoff as small
as possible, it was fine that his payoff was moderate.

PayoffTable

The Reason for Your Decision on Participation(6) How did you choose your investment number when you participated in investment?

Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

When your opponent participated in investment:
I took a safe strategy (chose around 7-9), because of the reason specified in (3).

7340

The same as the above.

When your opponent did not participate in investment:

PayoffTable

The Reason for Your Decision on Participation

I tried to maximize my own payoff, regardless of my opponent's payoff.

The same as the above.

(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
2658

I chose the number maximizing my payoff.

145

One should participate in investment if his prime concern is his own payoff. I would like to avoid the case where neither of
us participates in investment and both receive low payoffs. Investing more than 9 units would just make my opponent
happy, because my payoff is not high, while my opponent's payoff is quite high.

146

ID Number = 8, Male, Earnings = 2476 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

12

6

3400

Because choosing this number would make less mistake.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

4

10

5095

I wanted to try several numbers.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

24

8

500

I wanted to try several numbers.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O¯
13

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
9
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

6

PayoffTable

The Reason for Your Decision on Participation
Because participation would be more beneficial than non-participation.

Your Payoff The Reason for Your Decision on Investment Number

Participation would be more beneficial than non-participation
Your Payoff The Reason for Your Decision on Investment Number

I wanted to try several numbers by participating in investment.
Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
1631

Choosing this number is most profitable.

PayoffTable

The Reason for Your Decision on Participation
Hopefully my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5907
PayoffTable

The Reason for Your Decision on Participation
Because there is some probability that my payoff will be large.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
66
Period 5 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 6 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
97
Period 8 of the Actual Experiment
w
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

9

6

PayoffTable

The Reason for Your Decision on Participation
I wanted to get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
5515

Choosing this number would be profitable.

PayoffTable

The Reason for Your Decision on Participation
Hopefully my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I want to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
6481

I want to get a high payoff.

PayoffTable

The Reason for Your Decision on Participation
I want to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because my opponent would choose a number between 6 and 8.

PayoffTable

The Reason for Your Decision on Participation
Hopefully my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

My opponent would choose 6 or 7.

PayoffTable

The Reason for Your Decision on Participation
I wish that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
5765

My opponent would choose 8 or 9.

Your Payoff The Reason for Your Decision on Investment Number
5766

Choosing this number would be profitable.

147

148

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.
67
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

98

PayoffTable

The Reason for Your Decision on Participation
Participation would be more profitable than non-participation.

Your Payoff The Reason for Your Decision on Investment Number
2210

I did not give my opponent a large payoff.

PayoffTable

The Reason for Your Decision on Participation
I wish that my opponent would also choose participation.

Your
Payoff
6339
PayoffTable

ID Number = 8, Male, Earnings = 2476 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?

I wish that my opponent would choose 8.

First I thought that the case ´ O where I did not participate in investment, but my opponent did would be most beneficial tome. In this case, however, my opponents rather reduced my payoff than maximized their own payoffs. Therefore I foundthat the case O O where both participate in investment was most beneficial to me in a middle of the experiment.

The Reason for Your Decision on Participation(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?

The Reason for Your Decision on Investment Number

Participation would be more profitable than non-participation.
Your Payoff The Reason for Your Decision on Investment Number
6478

Choosing 7 would be most profitable.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

4. If I can make my opponent's payoff as small as possible, it is fine that my payoff is moderate.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:

7340

Choosing 7 would make little mistake.

First I thought that the case where I did not participate in investment, but my opponent did would be best for me. However,I found that non-participation was not so profitable and very risky in a middle of the experiment, and so I participated ininvestment at all the rest of periods.

PayoffTable

The Reason for Your Decision on Participation(6) How did you choose your investment number when you participated in investment?

The same as the above.

When your opponent participated in investment:

Your Payoff The Reason for Your Decision on Investment NumberYour Payoff The Reason for Your Decision on Investment Number
7250

There is some probability that my payoff is large.

I chose 6-8, because my payoff was reasonable and my opponent's payoff was not very high.
When your opponent did not participate in investment:
I rather reduced my opponent's payoff than maximized my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
It would be best to participate in investment and choose around 6-8 at all periods, because my payoff would be reasonably
high and be similar to my opponent's payoff.

149

150

ID Number = 9, Male, Earnings = 2955 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

9

12

7085

Because I expected that my opponent would choose the average
investment number (12).

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You
O
¯

Your
Opponent
´
¯

8
You
O
¯
2

Your
OpponentO¯
10Invest. Num.
7
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
7Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation
Because it is clear that there is a big loss when both choose 'nonparticipation'.

Your Payoff The Reason for Your Decision on Investment Number

I took a bleak.
Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.

PayoffTable

7

7

PayoffTable

The Reason for Your Decision on Participation
Because of my failure at practice period 2.

Your Payoff The Reason for Your Decision on Investment Number
1282

I do not like to write the number 13 simply (to maximize my payoff).

PayoffTable

The Reason for Your Decision on Participation'Non-participation' is not a fun. Because this is practice, I would like tohave a fun.

Your Payoff The Reason for Your Decision on Investment Number
4393

PayoffTable

I wanted to see what would happen if I choose a wild number before theactual experiment.

The Reason for Your Decision on Participation
Everyone would participate in investment, because there is enough time(ten minutes) to consider. I took a counterplot.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Because I was revenged for non-participation at period 1.

Your Payoff The Reason for Your Decision on Investment Number
2210

If I choose the number maximizing my payoff, my opponent's payoff isvery large. I am angry about it.

PayoffTable

The Reason for Your Decision on Participation
Choosing non-participation is boring in this game.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
5
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

84Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

11

PayoffTable

The Reason for Your Decision on Participation
It is efficient for me to participate in investment as far as myopponent also does.

Your Payoff The Reason for Your Decision on Investment Number
7345

Everyone seems to be experienced and so my opponent would choose 69.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

If I choose the number maximizing my payoff, my opponent's payoff isvery large. I am angry about it.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

My opponent would choose 7 or 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6115

To reduce my opponent's payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4420

Choosing this number would result in a reasonable payoff safely (I halt
an attack on my opponent).

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
10339

Because it would be most efficient to choose this number as at period 9.

Your Payoff The Reason for Your Decision on Investment Number
6478

My opponent would choose 8-10.

151

152

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

78

Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

Payoff
Table

Everyone seems to settle down to choosing 7 or 8. Because I will nevermeet the same person, it is interesting to choose 7 to spite my opponent.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above. Spiting my opponent means reducing his payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340
PayoffTable

The same as the above.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

ID Number = 9, Male, Earnings = 2,995 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
Payoff tables 2 and 3 are little meaningful. I almost always the north-west side of Payoff Table 1, because none would
choose a large investment number.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
It is desirable that my opponent's payoff is not larger than my payoff, and my payoff is moderate.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
First I intended to give my opponent a metal blow by choosing non-participation. However, I found it meaningless at early
periods.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I tried to choose the number that is smaller than my opponent's number by 1. This is because my payoff is larger than myopponent's by doing so.
When your opponent did not participate in investment:
My opponent tended to receive a high payoff. I tried to reduce my opponent's payoff as far as my payoff did not decreasemuch.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Non-participation in investment often results in a loss, because my opponent may not participate in investment, or my
opponent can control my payoff when he participates in investment. Concerning investment numbers, it is important tobalance my investment number and my opponent's.

153

154

ID Number = 10, Male, Earnings = 3199 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

Your
Opponent
O
¯

9

12

7085

Because by choosing this number, I would surely receive a reasonablepayoff.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investmentO¯

Invest. Num.
Practice 3

7

The Reason for Your Decision on Participation
Because I wanted to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number

Participation would be more profitable than non-participation.
Your Payoff The Reason for Your Decision on Investment Number
1148

I did not like that my opponent got a large payoff.

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

9

13

7844

From my experience at practice 1. Then I got a large payoff.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment
Invest. Num.

You

Payoff
Table

´
¯

0

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

8

Because I expected that my opponent would participate in investment.
Your Payoff The Reason for Your Decision on Investment Number

I would like to choose 'non-participation' once at least.
Your Payoff The Reason for Your Decision on Investment Number
500

PayoffTable

The Reason for Your Decision on Participation
Because I failed by choosing non-participation at practice 4.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected that my opponent would choose a similar number.

PayoffTable

The Reason for Your Decision on Participation
Because of my success at the last period.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
At period 2 my opponent did not participate in investment
and I felt mortified.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
11
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
79Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6478

I expected that my opponent would choose around 8.

PayoffTable

The Reason for Your Decision on Participation
I will not choose 0 if my opponent does not participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
2386

Not in particular.

PayoffTable

The Reason for Your Decision on Participation
It is significant to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
10339

Not in particular.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8271
PayoffTable

7 is a lucky number.
The Reason for Your Decision on Participation
I will continue to participate in investment from now on.

Your Payoff The Reason for Your Decision on Investment Number
7340

I will continue to choose 7.

PayoffTable

The Reason for Your Decision on Participation
Because I like to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I like the number 7.

PayoffTable

The Reason for Your Decision on Participation
It would be profitable to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6478

Choosing 7 would be reasonable.

Your Payoff The Reason for Your Decision on Investment Number
4904

155

156

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
78
NumberPeriod 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
77
NumberPeriod 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

6

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected that my opponent would choose about 7.

PayoffTable

The Reason for Your Decision on Participation
Because I like to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6478

Because my opponent would choose 6-9.

PayoffTable

The Reason for Your Decision on Participation
Because my opponent would also participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7340

Payoff
Table

Because my opponent would choose around 7.

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Invest. Num.
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

ID Number = 10, Male, Earnings = 3199 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
Not in particular.
I used Payoff Table 1 when both I and my opponent participated in investment. I used both Payoff Table 2 and Payoff Table
3, when my opponent participated in investment, but I did.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Participation would be good both for me and for my opponent (if my opponent also participates in investment).
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:

The same as the above.
Your Payoff The Reason for Your Decision on Invest. Num.
5766

I found choosing 8 would be better than choosing 7.

I always chose 7. But I think I could receive higher payoffs by choosing 8 instead of 7.
When your opponent did not participate in investment:
At the first time I chose the number maximizing my payoff. At the second time I chose a smaller number so that my
opponent did not get a high payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
I think that I should care only about my payoff and always invest 8 units. Also, non-participation should not be chosen,because it makes my opponent feel uncomfortable and I may not receive a high payoff.

157

158

ID Number = 11, Male, Earnings = 2633 yen
Practice 1

Participation
in investment

You
´
¯

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation
I did not participate in investment because everyone would participate ininvestment at the first time.

Your Payoff The Reason for Your Decision on Investment Number
Investment
NumberPractice 2

Participation
in investment
Invest. Num.
Practice 3

You
´
¯

You

6

1416

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation
Something tells me that non-participation would be more profitable thanparticipation.

1815
PayoffTable

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

11

7

3918

Because my opponent's investment number would be small.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investmentO¯

Invest. Num.

87Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Invest. Num.

80

The Reason for Your Decision on Participation
I feel non-participation would make both worse-off.

Your Payoff The Reason for Your Decision on Investment Number

Participation would be more profitable than non-participation.
Your Payoff The Reason for Your Decision on Investment Number
3915

Payoff
Table

Because I expected that my opponent's investment number would be 6-8.

The Reason for Your Decision on Participation
Non-participation is never profitable. My opponent would participate ininvestment if he is not silly.

Your Payoff The Reason for Your Decision on Investment Number
2210

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.
7
7
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Payoff
Table

PayoffTable

This person, No. 20, did not understand the situation at alleven after 4 periods of practice. Choosing '7' will teach him a good
lesson.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2386

I found that choosing '8' would be most profitable to the average
investment numbers of my opponents, 6-8, over 4 periods of practice.

159

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

The Reason for Your Decision on Participation

The case O O is better than the case ´ O. Clearly, if both invest 6-8 units,
both receive reasonable payoffs and can avoid big losses.
Your Payoff The Reason for Your Decision on Investment Number
6478

Choosing this number is safe.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

Why did not my opponent participate in investment? Someone might notparticipate in investment at the latter periods with psychological warfare.
But this is still the begging of the game. Why did not he choose aprofitable action? You should make a profit rather than enjoy yourself.
Did you understand it?

PayoffTable

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number

7

Your
OpponentO¯

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

The case ´ O is more profitable than the case ´ O, but the case O O is mostprofitable.
Your Payoff The Reason for Your Decision on Investment Number
7345

Choosing this number is safe and most reasonable. If both of us choose 7
or 8 without any serious consideration, we can get good profits with lesseffort.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

No other choice.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345(8, 8) would be settled.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

If you invest 0, your opponent does not more than 8. I cannot see why
my opponent did not understand it.

160Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

No outcome other than (8, 8) will occur.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

Why are you so silly, No. 4? Think about the meaning of investment.
The average investment number in the market has already been known.

PayoffTable

The Reason for Your Decision on Participation

The person who does not participate in investment must be foolish. Why
should I participate in investment? Because I can
increase my own money.
Your Payoff The Reason for Your Decision on Investment Number
6526

If my opponent invest in an attempt to maximize his profit, he should
write 8 because the average investment number is 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 11, Male, Earnings = 2633 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I used only Payoff Table 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
The case O O (where both I and my opponent participate in investment) is more beneficial to both me and my opponent thanthe case O´ (in which I participate in investment, but my opponent does not) and the case ´O (in which my opponent
participates in investment, but I do not). This is clear from the fact that the average investment number is around 6-8. It is
hard to find the reason why non-participation is more advantageous than participation.
(6) How did you choose your investment number when you participated in investment?

7345

The same as the above.

When your opponent participated in investment:

PayoffTable

The Reason for Your Decision on Participation

The average investment number was around 6-8. Thus I almost always chose 8 so that both my payoff and my opponent's
payoff were high.

The same as the above.
Your Payoff The Reason for Your Decision on Invest. Num.
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

When your opponent did not participate in investment:
I chose 7 to receive a moderate payoff. I also intended my opponent to realize the disadvantage of non-participation.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
First of all, the purpose of investment is to increase my own property. It is not desirable to compete with others and trip
others up because it may lead to my own loss. It is good to participate in investment positively in order to capture the stateof the market. By investing 8 units, my payoff is highest for the average investment number 6-8. If my opponent also
realizes this fact, both of us receive high payoffs.

The same as the above.
Your Payoff The Reason for Your Decision on Invest. Num.
6526

The same as the above.

161

162

ID Number = 12, Male, Earnings = 3284 yen
Practice 1

Participation
in investment
Invest.Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

You
O
¯

Your
Opponent
O
¯

7

10

5688

From the payoff tables, I would get a reasonable payoff on average byinvesting this amount.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You
O
¯

Invest. Num.
Practice 40Invest. Num.

You
O
¯

Your
Opponent´¯

YourOpponent´¯

7Your Payoff The Reason for Your Decision on Investment Number

I would like to see how my opponent behaves when I do not participate
in investment. (Perhaps he would choose 13.)Your Payoff The Reason for Your Decision on Investment Number

Invest. Num.
11
Period 2 of the Actual Experiment
w
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
6

PayoffTable

8

The Reason for Your Decision on Participation
The same as practice 1.

Your Payoff The Reason for Your Decision on Investment Number
500

To prevent my opponent from getting a large payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as practice 1.

Your Payoff The Reason for Your Decision on Investment Number
1148

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.

The Reason for Your Decision on Participation
I would like to see how my opponent behaves when I participate ininvestment (because this is practice).

500

Participation
in investment

Participation
in investment

Payoff
Table

PayoffTable

To prevent my opponent from getting a large payoff.

The Reason for Your Decision on Participation
Because I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
2658

Choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
It is not fun to choose non-participation.

Your Payoff The Reason for Your Decision on Investment Number
5681

Because my payoff would be high on average by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
Because my opponent's payoff is surely small if I do not participate ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
7237

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
811Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

87Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526
Payoff
Table

Because my payoff as well as my payoff would be high on average.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
10173

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

If I do not participate in investment, my opponent's payoff is small. Also
I risk my payoff because the case ´ ´ might happen.
Your Payoff The Reason for Your Decision on Investment Number
6526

Both I and my opponent would receive high payoffs on
average. (Choosing 8 is better than choosing 6 or 7 if my opponent
chooses 6, 7, or 8.)

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

Because my payoff would be high on average.

163

164

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345
PayoffTable

The same as the above.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

ID Number = 12, Male, Earnings = 3284 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I always used Payoff Table 1 to make decisions.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
Non-participation always makes my opponent's payoff low.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
Basically I chose 8.
When your opponent did not participate in investment:
I chose 11 to maximize my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
By Payoff Table 1, I found my best investment number for each investment number of my opponent (11 for 0, 11 for 1, ..., 8
for 8, ..., 0 for 24). When both I and my opponent choose 8, I choose my best number for the number he chooses, and my
opponent also chooses his best number for the number I choose. This situation would be less risky for both. Therefore I
think choosing 8 is the best choice.

165

166

ID Number = 13, Male, Earnings = 2798 yen
Practice 1

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

8

12

7206

By looking at the supplemental tables 1-2, I thought there is highprobability that choosing this number will make my payoff high.

You

PayoffTable

The Reason for Your Decision on Participation

Practice 2

You

PayoffTable

The Reason for Your Decision on Participation
I tried participation because this is practice.

Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 3

10

4

2708

I expected that everyone would reduce his investment number.

You

PayoffTable

The Reason for Your Decision on Participation

To get used to this experiment. The same as period 1.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

7

6

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯Your Payoff The Reason for Your Decision on Investment Number
Invest. Num.
7
6
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

10

10

5596

My opponent would choose a number between 3 and 10.

Invest. Num.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯Participation
in investment´¯

Invest. Num.

Your Payoff The Reason for Your Decision on Investment Number

To look at what happens.
Your Payoff The Reason for Your Decision on Investment Number

8

6

500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.
11
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

It would be disadvantageous to declare non-participation.

6

7

PayoffTable

The Reason for Your Decision on Participation

I would get 8000 if I do not participate in investment, but suchan action is risky at the first time. I want to try non-participation after
accumulating enough payoffs.
Your Payoff The Reason for Your Decision on Investment Number
2658

The only thing I can do is to choose 11 to receive the highest payoff.

PayoffTable

The Reason for Your Decision on Participation
I had better looking at how my opponent behaves.

Invest. Num.
86Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯Your Payoff The Reason for Your Decision on Investment Number6339

I am happy if my opponent chooses 8 or 9. I hope so.

Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

167

8

7

PayoffTable

The Reason for Your Decision on Participation

Investing nothing (non-participation) is not a good choice at this stage. I
will do it only after my payoff per period has been constantly at least
5000 (my goal is to get at least 5000 points per period).
Your Payoff The Reason for Your Decision on Investment Number
5681

My opponent would choose a number between 5 and 11. Choosing 7 issafe both when my opponent's number is 5 andwhen it is 11.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I continue to participate in investment until my payoff per period has
been constantly at least 5000.

Your Payoff The Reason for Your Decision on Investment Number
5766

Choosing this number would be best if my opponent chooses a number
between 6 and 8. I can get 5000 points even if he chooses 5.

PayoffTable

The Reason for Your Decision on Participation

At previous three periods, my opponents chose participation andinvested 6 units. My opponent at this period would also choose
participation.
Your Payoff The Reason for Your Decision on Investment Number
5766

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I get 8278 points in the case 0-11 and 7345 points in the case
8-8. I prefer the latter to the former.

Your Payoff The Reason for Your Decision on Investment Number
7345

Choosing 8 is good if my opponent chooses a number between 6 and 9.

PayoffTable

The Reason for Your Decision on Participation
If my opponent is a normal person, he would invest 11 units, and mypayoff would be 8278 points.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I would like to get reasonable payoffs constantly.

Your Payoff The Reason for Your Decision on Investment Number
6526

My opponent would choose a number between 6 and 8.

168Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
83
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
9
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation

ID Number = 13, Male, Earnings = 2798 yen(1) Did you understand the rules of the experiment?

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
3831

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I think only Payoff Table 1 is sufficient.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.

Safety is important for me.
Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
If I do not participate in investment, my payoff would beeither 706 or 8278. The gap between them is too large.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
This is a gamble. Everyone would not participate ininvestment at the final period.

Your Payoff The Reason for Your Decision on Investment Number
5907
PayoffTable

The Reason for Your Decision on Participation

There is high probability that my opponent will choose non-participation(´).
Your Payoff The Reason for Your Decision on Investment Number
7345

My opponent would choose a number between 6 and 8.

(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
I did not participate in investment only if I went a gamble to get a high payoff.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
My opponents almost always selected 6-8 only. Thus I always selected 8 to receive a high payoff for such numbers.
When your opponent did not participate in investment:
I invested 11 units so that my payoff is as high as possible.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
(1) Never participate in investment and get 8278 points at several periods.
Or(2) Invest 8 units at all periods.

169

170

ID Number = 14, Female, Earnings = 2538 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

12

9

4663

As a first step I chose a middle number.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

9

3

2272

I expected that my opponent would invest at least 10 units.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

6

7

3610

I expected that my opponent would invest at least 10 units.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

3

10

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

0

PayoffTable

The Reason for Your Decision on Participation
As a first step I participated in investment.

Your Payoff The Reason for Your Decision on Investment Number

Because I wanted to participate in investment.
Your Payoff The Reason for Your Decision on Investment Number

Because I wanted to participate in investment.
Your Payoff The Reason for Your Decision on Investment Number

My expectation proved wrong, but it is interesting.
Your Payoff The Reason for Your Decision on Investment Number
4769

PayoffTable

I expected that my opponent would invest at least 7 units.

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 5 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
97
Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

7

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6481
PayoffTable

I expected that my opponent would invest at least 6 units.
The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number6339

I expected that my opponent would invest at least 6 units.

Your Payoff The Reason for Your Decision on Investment Number
706

171

172

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would invest at least 6 units.

ID Number = 14, Female, Earnings = 2538 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I looked at Payoff Table 1 and Supplemental Payoff Table 1-2.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
I did not participate in investment at early periods. It was interesting to see the various responses of my opponents when I
chose non-participation.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I chose 6-9, because both my payoff and my opponent's payoff were reasonably high.
When your opponent did not participate in investment:
I chose 11, because I got the highest payoff. I expected my opponent would also choose 11 when I did not participate ininvestment, but my opponent did. However, this expectation did not come true.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
The best choice would be to participate in investment and choose an investment number so that both I and my opponent get
reasonably high payoffs. This is because it was difficult to expect my opponent's investment number when I did notparticipate in investment.

173

174

ID Number =15, Male, Earnings = 3118 yen
Practice 1

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

7

9

Practice 2

Participation
in investment
Invest. Num.
Practice 3

You

You
O
¯

Your
Opponent´¯

13Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

80

Practice 4

Participation
in investment

You

You
´
¯

Your
Opponent´¯

Invest. Num.

78

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation

I thought my payoff would be higher by choosing
participation than by doing non-participation when looking
at payoff tables.
Your Payoff The Reason for Your Decision on Investment Number
5000

PayoffTable

I expected that my opponent would choose 7 or 8. I expected from thepayoff tables that choosing this number would be most beneficial underthat expectation.
The Reason for Your Decision on Participation
From my success in practice 1.

Your Payoff The Reason for Your Decision on Investment Number
1631

Because choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
My payoff would be higher by choosing participation than by choosing
non-participation.

Your Payoff The Reason for Your Decision on Investment Number
1282

Payoff
Table

Because choosing this number would be most beneficial under the
expectation that my opponent would choose 7 or 8.
The Reason for Your Decision on Participation
I thought it is interesting to choose non-participation by observing theresults at practice 2 and 3.

Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

PayoffTable

11

PayoffTable

The Reason for Your Decision on Participation
First of all, I will participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected my opponent to choose an investment number
between 7 and 9.

PayoffTable

The Reason for Your Decision on Participation
Because my payoff would be higher by choosing participation than bychoosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because choosing this number maximizes my payoff.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

79Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
5
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

175

7

5

6

PayoffTable

The Reason for Your Decision on Participation
Because my failure at period 2 of the actual experiment.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Because the result at period 3 was not good.

Your Payoff The Reason for Your Decision on Investment Number
6478

Because I expected my opponent to choose an investment number
between 7 and 9.

PayoffTable

The Reason for Your Decision on Participation
Because my payoff would be better by participating in investment thanby not participating.

Your Payoff The Reason for Your Decision on Investment Number
8271

I expected my opponent to choose an investment number between 7 and9.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4950

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5272

Because I expected my opponent to choose around 6.

176

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
79Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

8

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected my opponent to choose a number between 7 and 9.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8271

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number

ID Number =15, Male, Earnings = 3118 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I mainly took a look at Payoff Table 1 when I decided my investment number. I sometimes used Payoff Table 3.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Before the actual experiment, I decided to choose non-participation only one time.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I selected a number between 7 and 9, because I expected my opponent would select a number between 7 and 9 by looking at
Payoff Table 1.
When your opponent did not participate in investment:

7340

The same as the above.

I chose the number maximizing my payoff.

PayoffTable

The Reason for Your Decision on Participation(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

177

I think it is best to participate in investment at all periods, because my payoff with non-participation would be smaller thanthat with participation. Further I think the best investment number is 7, because my opponent would also choose a number
between 7 and 9 many times.

178

ID Number = 16, Male, Earnings = 3065 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You
O
¯

Your
Opponent
O
¯

9

12

7085

My opponent would invest about half of 24 units. Under thisexpectation, my payoff is large by investing about 9 units.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

10

7

3981

I chose a number close to half of 24 and wanted to look at what would
happen.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13
You
´
¯

Invest. Num.

Your
Opponent
O
¯
7

8

7

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

6

The Reason for Your Decision on Participation
As a first step I participated in investment.

Your Payoff The Reason for Your Decision on Investment Number

I attempted to get a large payoff in the case where both participate ininvestment.
Your Payoff The Reason for Your Decision on Investment Number

I would like to avoid the risk that nether participates in investment.
Your Payoff The Reason for Your Decision on Investment Number
1631

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

Payoff
Table

PayoffTable

To maximize my payoff in the case O ´.
The Reason for Your Decision on Participation
Hopefully my opponent would participate in investment and I would geta large payoff by not participating in investment.

Your Payoff The Reason for Your Decision on Investment Number
1815

PayoffTable

The Reason for Your Decision on Participation
It would be best that both participate in investment and get reasonablepayoffs each other.

Your Payoff The Reason for Your Decision on Investment Number
6526

PayoffTable

My opponent would choose around 10. Under that expectation, I would
receive a reasonably high payoff by choosing this number.
The Reason for Your Decision on Participation

Both my opponent and I would like to avoid the risky case (´´) where
neither of us participates in investment.
Your Payoff The Reason for Your Decision on Investment Number
5681

I chose a relatively small number to get a reasonably high payoff evenwhen my opponent chose the same strategy.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

87Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
79Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

179

8

8

11

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2386

I did not permit only my opponent to enjoy a high payoff. So I chose 8 toreduce his payoff, although my payoff also decreases.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected my opponent to choose 7 or 8.

PayoffTable

The Reason for Your Decision on Participation
Because I would like to avoid the risk that neither of us participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
7345
PayoffTable

I expected my opponent to invest 7 or 8 units.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest 7 or 8 units as I did,and he would take a safe action, but not went on the gamble.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8271

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
10173

The same as the above.

180

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Invest. Num.
87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment
¯
¯
7

8

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

Payoff
Table

PayoffTable

My opponent would expect me to invest 11 units. But I prevent him fromgetting a high payoff.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would take an action similar to mine.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210
PayoffTable

The same as period 10.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest around 7, 8, or 9 units as I did.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

ID Number = 16, Male, Earnings = 3065 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
The payoff changes variously, depending on my investment number as well as my opponent's.
I referred to Payoff Table 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
5. If my payoff is the same as my opponent's payoff, I do not care about the absolute value of my payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
There is a heavy loss if neither of us participates in investment. Rather it would be better to participate in investment at a ll
periods and get reasonable payoffs steadily.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I expected my opponent would also do behavior similar to mine, and I chose a number so that both of us got reasonably
high payoffs.
When your opponent did not participate in investment:
I lose heavily if my opponent does not participate in investment. If I try to maximize my own payoff, I play right into my
opponent's hands and he gets a high payoff. Therefore I reduced my investment number so that the decrease in my payoff
was smaller than the decrease in my opponent's payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

The same as the above.

It is good to participate in investment as many times as possible in order to cooperate with my opponent. I should try toenlarge mutual benefit, not my own payoff only. If both of us choose investment numbers such that our payoffs are close,
we will reach an agreement and there will be no battle.

181

182

ID Number = 17, Male, Earnings = 3021 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

12

8

4213

Because I expected that nobody would invest a large amount.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13
You
´
¯

Your
OpponentO¯

Your Payoff The Reason for Your Decision on Investment Number

I wanted to try participation one more time.
Your Payoff The Reason for Your Decision on Investment Number
1631

Because my opponent did not participate in investment.

PayoffTable

The Reason for Your Decision on Participation
Non-participation would be more profitable thanparticipation.

Your Payoff The Reason for Your Decision on Investment Number
6117
Payoff
Table

O
¯

Your
Opponent
O
¯

7

8

You

Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment
¯
¯
6

9

The Reason for Your Decision on Participation
First of all I tried participation.

13

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
It is more fun to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
4368

Payoff
Table

Because investing this amount would be most profitable on average.

The Reason for Your Decision on Participation
Because I expected that everybody would participate in investment at thefirst period.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I felt that my opponent would participate in investment andinvest a large amount.

Your Payoff The Reason for Your Decision on Investment Number
6339

Because I felt that my opponent would invest a large amount.

PayoffTable

The Reason for Your Decision on Participation
Because participation would be efficient.

Your Payoff The Reason for Your Decision on Investment Number
8209

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
66
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
97
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
89Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
77
NumberPeriod 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

7

PayoffTable

The Reason for Your Decision on Participation
I will continue to participate in investment for a while.

Your Payoff The Reason for Your Decision on Investment Number
5515

Because investing this amount is efficient.

PayoffTable

The Reason for Your Decision on Participation
I will continue to participate in investment for a while.

Your Payoff The Reason for Your Decision on Investment Number
6481

Because I expected my opponent to invest a small amount.

PayoffTable

The Reason for Your Decision on Participation
I will participate in investment a little longer.

Your Payoff The Reason for Your Decision on Investment Number
8225

Because my opponent would invest around 6 or 7 units.

PayoffTable

The Reason for Your Decision on Participation
I still participated in investment.

Your Payoff The Reason for Your Decision on Investment Number
6478

My opponent would invest a relatively large amount.

PayoffTable

The Reason for Your Decision on Participation
I challenged non-participation although it was risky.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I am obstinate.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
I finally recognized that non-participation would not pay me.

Your Payoff The Reason for Your Decision on Investment Number6339

I expected my opponent to invest a large amount.

Because I felt my opponent would invest a large amount.

183

184

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
811Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

8

PayoffTable

The Reason for Your Decision on Participation
Wishing I can get a high payoff this time.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because most of my opponents have invested around 6 or 7 units.

PayoffTable

The Reason for Your Decision on Participation
Because 'non-participation' is too risky.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because most of my opponents have invested around 6 or 7 units.

PayoffTable

The Reason for Your Decision on Participation
It would be risky if I did not participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
10173

Because I wanted a high payoff.

PayoffTable

The Reason for Your Decision on Participation
Participation is safer than non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7237

Hopefully my opponent would invest a large amount.

PayoffTable

The Reason for Your Decision on Participation
Off course I participated in investment because this is the final period.

Your Payoff The Reason for Your Decision on Investment Number
7237

Hopefully my opponent would invest a large amount again.

ID Number = 17, Male, Earnings = 3021 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I took a look at Payoff Table 1 only.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
I did not participate in investment a few times, because I could receive a high payoff if I did not participate in investment,
but my opponent did.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I expected my opponent's investment number, and then I chose the investment number maximizing my payoff for that
expected number.
When your opponent did not participate in investment:
I chose a number so as to make my payoff as high as possible.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
The best choice: 6-8
The reason: Because everyone usually invests around 6-8 units, my payoff may become small if I invest larger units or
smaller units.
The risk for non-participation is so high that everybody will participate in investment at later periods. In addition, it would
be better to submit a participation card and an investment card simultaneously.

185

186

ID Number = 18, Male, Earnings = 2430 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

10

7

3981

Choosing this number is profitable when my opponent's investment
number is small.

You

PayoffTable

The Reason for Your Decision on Participation

Because this is the first time.
Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 3

6

9

4850

My opponent's payoff is at most 3520 when I choose this number.

You

PayoffTable

The Reason for Your Decision on Participation

Because my payoff at the previous period was bad.
Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

0

8

2299

I always get a payoff which is better than my opponent's.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment
Invest. Num.

O¯
0Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
08Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

If I choose non-participation at this first stage, I meet the wishof my opponent.

11

PayoffTable

I do not like to receive a payoff which is smaller than my opponent's.

The Reason for Your Decision on Participation
If my opponent chooses participation (O), it is most profitable for him toinvest 11 units.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
To avoid the case in which neither of us participates in investment (´´).

Your Payoff The Reason for Your Decision on Investment Number
4904

I always get a payoff which is higher than my opponent's.

PayoffTable

The Reason for Your Decision on Participation
The same as period 1.

Period 4 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 5 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
98Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
This would be a safe policy!?

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´ (where neither of us participates in investment).

Your Payoff The Reason for Your Decision on Investment Number
7250

Choosing this number would be profitable.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340
PayoffTable

The same as the above.
The Reason for Your Decision on Participation
This is a gamble.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´.

Your Payoff The Reason for Your Decision on Investment Number
2658

Choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
This is a gamble.

Your Payoff The Reason for Your Decision on Investment Number
4018

Your Payoff The Reason for Your Decision on Investment Number
8278

187

188

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 13 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
This is a gamble.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´.

Your Payoff The Reason for Your Decision on Investment Number
7340

Choosing this number is profitable.

PayoffTable

The Reason for Your Decision on Participation
This is a gamble.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´.

Your Payoff The Reason for Your Decision on Investment Number
2658

Choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´.

Your Payoff The Reason for Your Decision on Investment Number
6478

Choosing this number is profitable.

ID Number = 18, Male, Earnings = 2430 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I mainly used Payoff Tables 1, 2, and 3. Before the actual experiment started, I spend ten minutes to write data of the payoff
tables into Supplemental Payoff Tables 2. I never used Supplemental Tables 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
4. I participated in investment several times, but the number of periods at which I did not participate in investment
was greater than the number of periods at which I did.
The reasons for your decisions on participation:
When my opponent participated in investment, but I did not, my opponent almost always chose the number maximizing his
payoff and I also received a good payoff.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I expected that my opponent would choose 6-9. I chose around 7-8 to get a good payoff for such numbers.
When your opponent did not participate in investment:
I chose the number maximizing my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
The opponent's payoff should be also considered in selecting an investment number. If I behave selfishly, I might get a large
payoff, but might lose a lot. All of us become happy if everyone considers both his own payoff and his opponent's payoff
when making an investment decision (this is an ideal).

189

190

ID Number = 19, Male, Earnings = 2961 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

You
O
¯

Your
Opponent
´
¯

6

You
´
¯

You
O
¯

Your
OpponentO¯

The Reason for Your Decision on Participation
To avoid the case in which neither of us participates in investment andour payoffs are quite low (500).

Your Payoff The Reason for Your Decision on Investment Number
1007

By choosing this number, my payoff is not low and my
opponent's payoff is not large.

PayoffTable

The Reason for Your Decision on Participation
Choosing non-participation is profitable with probability 3/4.

Your Payoff The Reason for Your Decision on Investment Number

13

6117

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation
My payoff would be higher than at practice 2.

Your Payoff The Reason for Your Decision on Investment Number

7

6

3266

I am selfish and my payoff would be largest by investing this amount.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

102Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 3 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.

PayoffTable

I practice the same thing as at the previous period once more.
Your Payoff The Reason for Your Decision on Investment Number
2038

PayoffTable

I expected my opponent's investment number.

The Reason for Your Decision on Participation
I had a big bet at the first time.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I again tried non-participation because I got savings at period
1.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
The third of the payoff obtained at the previous period is compared withthe payoff obtained when both participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
706

191

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

611

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

68Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 9 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

PayoffTable

The Reason for Your Decision on Participation
I safely participated in investment this time.

Your Payoff The Reason for Your Decision on Investment Number
10384

Choosing this number would be safest, comparing with thecase in which both payoffs are 706.

PayoffTable

The Reason for Your Decision on Participation
This is a safe choice.

Your Payoff The Reason for Your Decision on Investment Number
7237

Choosing a middle number would be profitable as at period 4 of theactual experiment.

PayoffTable

The Reason for Your Decision on Participation
Because the number of my opponents who did not participate
in investment decreases.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected my opponent to choose 6, 7, or 8.

PayoffTable

The Reason for Your Decision on Participation

My opponent would choose non-participation (´) if
he is very greedy.
Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
If both participate in investment, I do not hurt my opponent, nor does myopponent.

Your Payoff The Reason for Your Decision on Investment Number2658

I narrowly escaped from receiving 706.

PayoffTable

The Reason for Your Decision on Participation
Because I was angry that my opponent did not participate in investment
at period 8.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I settled down now. I would like to avoid that my payoff is 706.

Your Payoff The Reason for Your Decision on Investment Number
6526

Choosing 8 is safest and it maximizes my payoff when my opponent's
number is between 6 and 8.

192

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

9

PayoffTable

The Reason for Your Decision on Participation
Participation is a safe strategy. Most people would have the badexperiences that their payoffs are 706.

Your Payoff The Reason for Your Decision on Investment Number
5766

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
Everyone seems to understand that participation is safe.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 19, Male, Earnings = 2961 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I took a look at Payoff Table 1. I found the number maximizing my payoff for each of my opponents' investment numbers. I
realized from a middle of the experiment that I could get the almost largest payoff by investing 8 units. After knowing a
knack about investment, I did not need to consider investment numbers carefully.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.

7345

The same as the above.

(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

PayoffTable

The Reason for Your Decision on Participation

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.

The same as the above.

The reasons for your decisions on participation:

Your Payoff The Reason for Your Decision on Investment Number
2386
PayoffTable

To punish the person who seeks only his own interest.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8225

The same as the above. Everyone looks like understanding
the situation.

At the first three periods, I went on the gamble that I did not participated in investment so as to get a large payoff. However
I realized that we could prevent a big loss when both of us safely participated in investment and invested 8 units, and so I
decided to participate in investment.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
8: My payoff is maximized by choosing 8 when my opponent invests 6-8 units.
When your opponent did not participate in investment:
11: My payoff is maximized by choosing 11.
8: The decrease of my payoff is relatively small, while the decrease of my opponent's payoff is relatively large.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
If everybody participate in investment and choose 8, none would suffer a large loss. I understood that taking selfish
behavior would lead to a serious problem. I am very happy to participate in the experiment.

193

194

ID Number = 20, Male, Earnings = 2346 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

12

9

4663

My opponent would also seek a reasonable payoff steadily.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

8

5

2942

Choosing this number would result in a reasonable payoff.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

10

10

5596

By choosing this number, my payoff would not be bad evenwhen my opponent's investment number is small.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

13

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 3 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
It would be safest to participate in investment and invest around 12 units.

Your Payoff The Reason for Your Decision on Investment Number

Participation would be profitable with high probability.
Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

My opponent would invest 13 units if I do notparticipate in investment, but my opponent does.
Your Payoff The Reason for Your Decision on Investment Number
6117

PayoffTable

The Reason for Your Decision on Participation
My opponent would participate in investment at the first time. If so, hewould invest 11 units.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
I do not understand why my opponent at period 1 invested 7 units. But I
tried non-participation once more.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
6
7
NumberPeriod 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.
11
Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

6

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4018

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I do not understand why my opponents invested 7 units. I
tried participation this time.

Your Payoff The Reason for Your Decision on Investment Number
5766

My opponent would choose 7, 8, or 9.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

If my opponent participates in investment, but I do not, I can only
imagine that my opponent would invest 11 units. So I tried nonparticipation, expecting that my opponent would choose participation.
Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation

Perhaps most of my opponents at the previous periods did notunderstand the payoff tables. I did not participate in investment,
expecting that my opponent would invest 11 units.
Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

It cannot be helped.
The Reason for Your Decision on Participation
Hopefully my opponent would invest 11 units.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation
Why? My plan did not work well. I participated in investment to get areasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

195

196

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
10
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

PayoffTable

The Reason for Your Decision on Participation
I had a bet once more. It is not meaningful to seek
the safety at this stage.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I do not understand why my opponent chose 0. I had a bet once more.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Not in particular.

Your Payoff The Reason for Your Decision on Investment Number
7031
PayoffTable

The Reason for Your Decision on Participation
Choosing 10 is mysterious. Anyway my strategy worked well and so I
tried non-participation again.

Your Payoff The Reason for Your Decision on Investment Number(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I almost always used Payoff Table 1 only.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
4. I participated in investment several times, but the number of periods at which I did not participate in investment
was greater than the number of periods at which I did.
The reasons for your decisions on participation:
As a matter of fact I planned to choose non-participation at all periods. However I changed my mind, because I could nothave things my own way many times.
(6) How did you choose your investment number when you participated in investment?

8278
PayoffTable

ID Number = 20, Male, Earnings = 2346 yen

The Reason for Your Decision on Participation
I decided no to participate in investment. If my opponent do notparticipate in investment, either, I will simply give up.

Your Payoff The Reason for Your Decision on Investment Number

When your opponent participated in investment:
Because my opponent always invested around 5-9 units, I continued to invest such units.
When your opponent did not participate in investment:
It did not occur.

8278(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
If you want to get a high payoff, do not participate in investment and let your opponent invest 11 units to earn 8278 perperiod (if you opponent do not participate in investment, give up). If you are satisfied with getting a normal payoff, itwould be best to invest 7-9 units continuously.

197

198

4. Data for the Tsukuba B Session (with the "Opponent" Wording)
4.1. Pairs of Subjects (ID Numbers) in the Tsukuba B Session: the Same as the Tsukuba A Session (see Table 3.1.).
4.2. Participation Decisions of Each Subject in the Tsukuba B Session: 1 = Participate, O = Not Participate
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12

1

Period 13
Period 14
Period 15

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

0
0
1
1
1
0
1
1
1
1
1
1

1
1
1
0
1
1
0
1
1
1
1
1

1
0
1
1
0
1
1
1
0
1
1
1

0
0
0
1
0
1
1
0
0
0
1
1

0
0
1
1
0
1
1
0
1
1
1
1

0
1
1
1
1
1
1
1
1
1
1
1

0
1
1
0
1
1
1
0
1
1
1
1

0
0
1
1
0
0
1
1
1
1
1
1

0
1
1
1
1
1
1
1
1
1
1
1

1
1
0
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
0
1
1
1
1

0
0
0
0
0
1
1
0
1
1
1
1

1
1
0
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1

0
1
1
1
1
1
1
0
0
1
1
1

0
1
0
0
0
1
1
0
1
0
0
1

0
0
0
1
1
1
1
1
0
1
1
1

0
0
0
0
1
1
0
0
0
1
0
0

1
0
1

1
1
0

1
1
1

1
1
1

0
1
0

1
1
1

1
1
1

1
1
1

1
1
1

1
1
1

1
1
1

1
1
1

1
0
1

1
1
1

1
1
1

1
1
1

1
1
1

0
1
1

1
1
1

0
0
0

4.3. Participation Decisions of Each Subject's Opponents in the Tsukuba B Session: 1 = Participate, O = Not Participate
ID #

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Period 1
Period 2
Period 3
Period 4
Period 5

0
0
0
1
1

1
0
0
1
1

0
1
1
1
1

0
1
1
0
1

0
0
0
0
0

0
0
0
1
1

0
0
1
0
1

0
1
1
1
0

1
0
1
1
0

1
0
1
1
0

0
1
1
0
1

0
1
1
1
1

0
1
1
1
1

0
1
1
1
0

1
0
1
1
1

1
1
0
1
1

0
1
1
1
1

1
1
1
0
0

1
1
0
1
1

1
1
0
1
1

Period 6

0

1

1

1

1

1

1

0

1

1

1

1

1

1

1

1

1

1

1

1

Period 7
Period 8
Period 9

1
1
1

1
1
0

0
1
0

0
0
1

1
0
0

1
1
1

1
1
1

1
1
1

1
1
1

1
1
1

1
0
1

1
1
1

1
0
1

1
0
1

1
1
1

1
1
1

1
0
1

1
1
0

1
0
0

1
0
1

Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1
1
1
1
1
1

1
1
1
1
1
1

1
1
1
0
1
0

1
1
1
1
1
1

1
1
1
0
1
1

1
0
1
1
0
0

1
1
1
1
1
0

1
0
1
1
1
1

1
1
1
1
1
1

1
1
1
1
1
1

0
1
1
1
1
1

1
1
1
1
1
1

1
1
1
1
1
1

1
1
1
1
1
1

1
1
1
1
1
1

0
1
0
1
1
1

1
1
1
1
1
1

1
1
1
0
0
1

1
1
1
1
0
1

1
1
1
1
1
1

115

4.4. Investment Numbers of Each Subject in the Tsukuba B Session (blank means non-participation).
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12

1

2

8
6
8

9
7
6
7
6

8
8

8

5

6

7
7

11
7
11

6
7

7
7
7

8
8

7
7
7
7

10
7
7

8
8
8

8
6
8
8
9

8

4

7

8

9

10

7

8
8

7
4
8
7
3
8

Period 13
Period 14
Period 15

3

8
9
11

7

0
0
11
8
11
8
11
11
11
0
8

11
6

6
6
6
7

9
8
8
9
7
6

7
7
8
7
8
5
8
7
7
7
7

11
9
8

7
7
11

7
7
9

7
7
7

8
6

6
6
7

11

7
11
7
8
7
7
7
7
7
7
7

7
8
7
7
8
8
8
7
8
7
8
8

7
7
8

8
8
8

12
13
14
15
16
17
18
19
20
11 11
7
8
7
6
11
7
6
0
6
7
8
6
6
7
7
8
6
6
6
8
7
8
9
6
8
6
8
8
7
8
8
9
7
6
8
8
9
7
7
7
7
8
8
7
8
11
8
8
8
5
8
11
8
8
6
7
7
6
8
7
8
8
8
7
8
8
8
8
8
8
7
7
8
7
8
8
8
8

8

8
8
8

8

7
7
7

8
7
7

8
6
6

8
8
8

11
7

4.5. Investment numbers of Each Subject's Opponents in the Tsukuba B Session (blank means non-participation).
ID #Period 1
Period 2
Period 3
Period 4
Period 5

1

2

3

4

5

6

7

8

9

7

7
8

Period 6

0
8

11
8

11
6
6
8

8

8

6

Period 7
Period 8
Period 9

8
8
8

7
8

Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

6
8
7
8
8
8

8
7
7
8
6
8

10

7
7

14

8
7

0
7

7
6
6
6

11
0
7

8

6
8
7
8

7

8

6

11

6

7

6

8

7
8
8

7
7
5

7
7
8

7
4
8

9
8
8

8

8

8

7
11
7

7

7
8
8

7

9
8
7
8
8

6

11
8
6
8
7
7

7
8
7
8
7
6

7
8
8
7
7

7
8
7
8
7
7

8
3
8
7
9
8

8
7

8
8

7
7
8
8

15

16

8

8

11

7

13

8

7

7
7
8
8
7
8

7
8

12

6
6

7
8
8
8

9
6
6

11

8

17

7
6

18

19

11
8
11

11
11

20

7
7

11
8

7
6

7
7
9

8
8

7
9
6
7

8

6

7

9

8

8

7

7

9
8
11

7

8
11

7

11

8

5
6
6

7
8
7
7
7
8

8
8
9
7
8
8

7
7
8

7
6
8
8

7

9

116

7
7
7
8

7
7
7
8
11
8
8

6
6
0
7
10
11
11

4.6. Pairs of Investment Numbers in the Tsukuba B Session (blank means non-participation and boldfaced numbers indicate data ofsubjects who did spiteful behavior).
Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #
1,6
1,5
1,10
1,3
6
7 1,16
8
8 1,8
1,12
7
8 1,9
4
8
8
2,10
8
7 2,8
2,18 112,4
11 2,118
8 2,14
8
8 2,3
8
8
9
7 2,163,93,7
11 3,179
6 5,203,10
6
8 4,20 11
3,15
6
7
7
7
8 3,13
4,8
4,6
6 4,9
7
6 5,197
8 4,140 4,16
8 6,19 11
7 4,12
5,7
9,20
5,15
7,18
5,8
5,11
6
8 6,188
7 5,137
7
11,20
10,19 11
6,14
8,17
6
6 6,7
8
6 6,10 11
7 7,177
7 6,12 118
7
0
12,19 1111,18
8
6
7 9,168
8 12,206
8 7,9
6
8 8,169
7 7,11
0 7,13
7
13,18 1112,17
7
6 8,128
6 10,157
7 13,198
6 15,207
6 9,15
7 8,10
8
7
5
14,17
13,16
6
7 9,11
7
7 11,14
14,18
16,19
8
7 10,147
9 17,20
715,16
7
8 14,15
11 19,20
12,13
6
7 15,177
9 17,188
9 11,138
8 18,19
11
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #1,11
8
8 1,177
6 1,13
3
8 1,188
7 1,2
8
8 1,19
8
8
8 1,4
2,20
2,13
8
8 2,5
8
7 2,159
7 3,20 10
2,17
8
6 2,6
6
8
3,19
3,12
7
8 3,4
7
8 3,147
8 4,198
8 3,16
7
7 3,5
7
4,18
11 4,114,13
8
8 5,184,15
8
7 7,20 11
7 6,20
0
5,17
5,10
7
7 7,196
8 5,12
8 6,17 11
8 5,14
8 8,1998
7
7
76,16 11
8 6,9 116,118
8 7,167
8 6,139,18
7
7 8,18
7
9
7
7,15
6
5 7,8
6
9 9,17
8 7,107
7 8,157
7 7,127
8 10,17
8
6
7
8,14
8
8 14,20
6
7 10,167
8 8,9
6
8 8,117
8 11,168
7
7 9,14
79,13
7
8 15,197
8 11,158
7 16,2010,13
7
8 9,10
7 12,15
8
7
7
7
10,12
7
8 16,1812,14
8
8 17,198
8 11,128
8 18,20 11
13,14
8
8
7

117

4.7. Payoffs of Each Subject in the Tsukuba B Session
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1
706
706
2386
6339
7345
706
7340
6751
7345
5681
6383
6526
7345
4904
7345

2
6526
2523
2658
8278
7345
7345
4018
7345
2003
7345
6526
6481
7345
5766
4904

3
2210
8278
5765
5681
4904
7237
2210
6339
706
7340
7340
7340
2615
6478
2210

4
706
706
4904
2658
4018
5681
2658
706
8278
4018
6526
7345
7345
6526
7345

5
706
706
2210
2210
706
7237
7340
706
2210
6478
7340
7340
706
7340
4018

6
706
706
706
5504
5766
6114
6526
6765
6765
6114
706
7345
6765
2523
2386

7
706
2658
6339
706
7237
7237
6478
4018
4762
8209
7237
6478
7340
7340
2658

8
9
10
706 4018 7340
5907 2210 2658
5766 6478 4904
5515 7345 6478
706 2210 2386
706 5766 10339
6481 6115 8271
6526 4420 7340
7345 7340 7340
5765 10339 6478
2210 7340 7340
6339 5681 6478
6478 7340 7340
7340 6478 6478
7250 6478 5766

11
122210 2658
2386 5681
6478 7237
2210 6339
7345 7237
5766 6339
7345 6526
2210 10173
7345 6526
2210 6526
6526 7345
7345 6526
7345 7345
6526 6526
6526 6526

118

13
2658
6339
5681
5681
5766
5766
7345
706
6526
7345
3831
7345
6526
5907
7345

14
706
8278
706
4018
706
7345
6481
706
7345
6339
7345
6526
6526
6526
7345

15
16
17
7340 6526 706
2658 5681 6339
4018 2386 8209
6478 7345 5515
8271 7345 6481
5681 6526 8225
4950 8271 6478
5681 7345 706
5272 10173 4018
7340 2210 6339
7340 6526 6526
8271 2210 7345
6478 6526 10173
7340 6478 7237
7340 7340 7237

18
198278 8278
4904 8278
8278 706
706 10384
706 7237
7250 7340
7340 6526
8278 2658
2658 706
4018 6526
4018 5766
7340 7345
706 7345
2658 2386
6478 8225

20
4018
4018
706
4018
5766
6339
8278
706
3244
5681
706
4018
7031
8278
8278

4.8. Record Sheets and Questionnaires for the Tsukuba B Session
ID Number = 1, Female, Earnings = 2568 yen
Practice 1

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

9

7

Practice 2

You

The Reason for Your Decision on Participation
As a first step I chose participation to look at what would happen.

Your Payoff The Reason for Your Decision on Investment Number
3980

Participation
in investmentO¯

Invest. Num.
Practice 3

5

8

3976

Because I expected that my opponent would choose a large number.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

12

6

3400

Because I expected that my opponent would write a number around 10.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

10

3

Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.

Payoff
Table

Because I expected that my opponent would choose a large investment
number.

Your
OpponentO¯Participation
in investment

You

PayoffTable

The Reason for Your Decision on Participation
Because I expected that a high payoff when choosing participation.

Your Payoff The Reason for Your Decision on Investment Number

Because I can get at least 500 by choosing participation.
Your Payoff The Reason for Your Decision on Investment Number

Because I expected a higher payoff by choosing participation than bychoosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number
2038

Payoff
Table

Because I expected that my opponent's investment number would bearound 7.

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation andan investment number around 11.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation and an
investment number around 11.

Your Payoff The Reason for Your Decision on Investment Number
706

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

Invest. Num.

67

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 6 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

48Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment
¯
¯
8

8

The Reason for Your Decision on Participation
Because my payoff would be higher than 706 by choosing participation.

Your Payoff The Reason for Your Decision on Investment Number
2386

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

119

8

Payoff
Table

PayoffTable

If I choose 8, then my opponent's payoff is 4904 and my payoff is 2386. If
I choose 11, then my opponent's payoff is 8278 and my payoff is 2658.
My payoff changes little, while my opponent's payoff does much.
The Reason for Your Decision on Participation
Because my payoff would certainly be higher than 706 by choosing
participation.

Your Payoff The Reason for Your Decision on Investment Number
6339

Because I expected that my opponent would choose a middle investment
number.

PayoffTable

The Reason for Your Decision on Participation
Because my payoff would be higher than 706 with highprobability.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected that my opponent would choose a number around 6.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would be about to choose
participation and an investment number around 11.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because choosing non-participation is risky.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected that my opponent would invest around 7 units.

PayoffTable

The Reason for Your Decision on Participation
Because choosing non-participation is risky.

Your Payoff The Reason for Your Decision on Investment Number
6751

Because I expected that my opponent would choose a middle investment
number.

PayoffTable

The Reason for Your Decision on Participation
Because both payoffs would be high if both choose participation.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected that my opponent would choose a similar investment
number.

120

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

38

Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

87Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation
Because both payoffs would be high if both choose participation.

Your Payoff The Reason for Your Decision on Investment Number
5681

Because I expected that my opponent would choose a middle number.

PayoffTable

The Reason for Your Decision on Participation
Because it would be more likely to get a high payoff by choosing
participation than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
6383

Because I expected that my opponent would choose an investment
number about 8.

PayoffTable

The Reason for Your Decision on Participation
Because it would be more likely to get a high payoff by choosing
participation than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because I expected that my opponent would choose a similar investment
number.

PayoffTable

The Reason for Your Decision on Participation
Because it would be more likely to get a high payoff by choosing
participation than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected that my opponent would choose a similar investment
number.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would be about to choose
participation and an investment number around 11.

Your Payoff The Reason for Your Decision on Investment Number(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
In particular I looked at Table 1 when I decided my investment number. If someone invests 24 units, he loses heavily, while
his opponent has a big money. I wonder if such a person exists. Because choosing a large number or a small number isrisky, everybody tended to choose about 8.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
It is desirable that my payoff is as high as possible, while my opponent's payoff is as small as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
When I did not participate in investment, I expected my payoff would be high by my opponent's investment. However,
because my opponent had the same idea, we destroyed ourselves. Therefore I tried to avoid non-participation. After all, thepayoffs were often high when both participated in investment.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
At early periods I chose the numbers randomly. But my opponents' investment numbers have been almost fixed from a
middle. Thus I chose numbers leading to high payoffs for those numbers.
When your opponent did not participate in investment:

The Reason for Your Decision on Participation
Because it would be more likely to get a high payoff by choosing
participation than by choosing non-participation.

(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
7345(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.

I chose the number so that only my opponent did not get a large payoff. For example, if I choose the number maximizing
my payoff, then my opponent's payoff is about 8000. On the other hand, if I choose a number (8) so that my payoff is notmuch different from the maximal payoff, then my opponent's payoff is about 5000. Therefore I chose the latter.

4904
PayoffTable

ID Number = 1, Female, Earnings = 2,568 yen

Because I expected that my opponent would choose a similar investment
number.

121

I think the best choice would be to participate in investment and invest about 8 units. This is because both I and my
opponent receive reasonable payoffs.

122

ID Number = 2, Male, Earnings = 2852 yen
Practice 1

Participation
in investment
Invest. Num.

Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment

Invest. Num.
Practice 4

You
O
¯

Your
Opponent
O
¯

12

9

4663

Because I thought that my payoff would be large by choosing thisnumber with high probability, taking account of my opponent's
investment number.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13
You
´
¯

You

Your
OpponentO¯

Invest. Num.

107Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
7Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

9

I expected a higher payoff by choosing participation than bychoosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number
1631

Because my payoff is maximized by choosing this number.

PayoffTable

The Reason for Your Decision on Participation

Because my payoff would be larger when my opponent chooses
participation, but I do not, comparing with the case in which both choose
participation.
Your Payoff The Reason for Your Decision on Investment Number

Payoff
Table

O
¯

8

Your Payoff The Reason for Your Decision on Investment Number

500

Participation
in investment

The Reason for Your Decision on Participation
I expected a reasonable payoff by choosing participation.

0
Your
OpponentO¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.
11
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

The average payoff is higher by choosing participation thanby choosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number
3981

Payoff
Table

There is good probability that my payoff is high by choosing
this number.

The Reason for Your Decision on Participation
I am afraid that my payoff would be low if my opponent chooses nonparticipation.

Your Payoff The Reason for Your Decision on Investment Number
6526

Payoff
Table

Because my opponent also chose participation, I expected to receive areasonable payoff safely and could avoid a big loss by choosing around 8.
The Reason for Your Decision on Participation
I am afraid that my payoff is low (706) if both choose non-participation.

Your Payoff The Reason for Your Decision on Investment Number
2523

Because my opponent did not participate in investment, I reduced his
payoff to the permissible level.

Invest. Num.
88Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.

123

6

PayoffTable

The Reason for Your Decision on Participation
Because I attempted to avoid the situation in which bothchoose non-participation and the payoffs are 706.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff is maximized by choosing this number.

PayoffTable

The Reason for Your Decision on Participation

Because my payoff would be larger when my opponent chooses
participation, but I do not, comparing with the case in which both choose
participation.
Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I would like to avoid the worst situation (neither of us participates ininvestment).

Your Payoff The Reason for Your Decision on Investment Number
7345

Because there is high probability that I steadily obtain a reasonablepayoff.

PayoffTable

The Reason for Your Decision on Participation

My payoff would be large when I do not participate in investment, but
my opponent does. However, when neither of us participates ininvestment my payoff is small. Therefore, I chose participation to receivea reasonable payoff safely.
Your Payoff The Reason for Your Decision on Investment Number
7345
Payoff
Table

Because I could receive a reasonable payoff steadily.
The Reason for Your Decision on Participation
Hopefully my opponent participates in investment.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Choosing participation is safe.

Your Payoff The Reason for Your Decision on Investment Number
7345

By choosing this number, I could ensure a reasonable payoff.

PayoffTable

The Reason for Your Decision on Participation

My opponent would not choose a large investment number even if heparticipates in investment, but I do not. Therefore I expected a large
payoff by choosing participation.
Your Payoff The Reason for Your Decision on Investment Number
2003

I chose the number so that my opponent's payoff was reduced to theextent that the decrease in my payoff is acceptable.

124Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

97

Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.

8

PayoffTable

The Reason for Your Decision on Participation
Because I can expect a reasonable payoff and there is high probability
that my opponent will participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because both payoffs are large even when I consider my opponent's
payoff.

PayoffTable

The Reason for Your Decision on Participation
Because I can expect a reasonable payoff.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because choosing this number is the safest choice.

PayoffTable

The Reason for Your Decision on Participation
I can expect a reasonable payoff.

Your Payoff The Reason for Your Decision on Investment Number
6481

Choosing 9 is not safe as doing 8, but my payoff might be higher and theloss would be small.

PayoffTable

The Reason for Your Decision on Participation
With higher probability I can expect a larger payoff bychoosing participation than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I can steadily receive a reasonable payoff for any investment
number of my opponent.

PayoffTable

The Reason for Your Decision on Participation
Because it is safe.

Your Payoff The Reason for Your Decision on Investment Number
5766

Choosing this number would maximize my payoff when considering my
opponent' behavior.

PayoffTable

The Reason for Your Decision on Participation

From data at the previous periods, there is high probability that my
opponent will participate in investment. If this happens,
I may receive a large payoff by choosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number

ID Number = 2, Male, Earnings = 2,852 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 2) in Practice(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I often used the payoff tables for the case in which both participate in investment. Considering not only my benefit but also
my opponent's behavior carefully, I chose the number maximizing my payoff.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
2. If my payoff is higher than my opponent's payoff, I do not care about the absolute value of my payoff, evenwhen the difference between my payoff and my opponent's is small.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
At first glance I thought non-participation might be more beneficial than participation. However, when I did not participate
in investment, but my opponent did, the number that my opponent chose was smaller than the number maximizing his
payoff. Then my opponent did not lose much, while I lost very much, comparing with the case in which my opponent
chooses the number maximizing his payoff. After all, I could receive a higher payoff by participating in investment. Also, I
would like to avoid the case in which neither of us participates in investment.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
My opponent did not want to lose in his payoff, either. Considering this point, I tried to maximize my payoff.
When your opponent did not participate in investment:
I prevented my opponent from receiving a large payoff, as long as the reduction of my payoff was permissible.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
I think that the total profit would be larger by participating in investment at all periods, because of the reasons mentioned
above.

4904

125

126

ID Number =3 , Male, Earnings = 2530 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

6

12

7172

Because my opponent would not choose a large number at the first time.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

9

6

3491

The same as the above.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

7

11

6432

Because my payoff would be large with high probability.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
2

24

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

9

6

PayoffTable

The Reason for Your Decision on Participation
When participating in investment, I can control my payoff by choosing an
investment number.

Your Payoff The Reason for Your Decision on Investment Number

Because I expected a higher payoff by choosing participation.
Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

Because I am sure that my payoff is low when I do not participate ininvestment.
Your Payoff The Reason for Your Decision on Investment Number
24369

PayoffTable

I expected that my opponent's investment number would bearound 10.

The Reason for Your Decision on Participation
To look at what will happen.

Your Payoff The Reason for Your Decision on Investment Number
2210

Because I did not like that my opponent' payoff was large.

PayoffTable

The Reason for Your Decision on Participation
Because I could ensure at least 7000 payoff by choosing
non-participation.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
Because I did not participate in investment at the last period.

Your Payoff The Reason for Your Decision on Investment Number
5765

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

68Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 9 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

8

PayoffTable

The Reason for Your Decision on Participation
Because I would like to maintain at least 10,000 payoff.

Your Payoff The Reason for Your Decision on Investment Number
5681

My opponent's investment number would be small.

PayoffTable

The Reason for Your Decision on Participation
Because my payoffs were only about 6,000 when I chose participation.

Your Payoff The Reason for Your Decision on Investment Number
4904
PayoffTable

The Reason for Your Decision on Participation
Because of my failure at the last period.

Your Payoff The Reason for Your Decision on Investment Number
7237

Payoff
Table

Because choosing this number would ensure a reasonable payoff on
average.
The Reason for Your Decision on Participation
Because I do not like the situation in which neither of us participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
2210

I considered the balance of my opponent's payoff (and my payoff).

PayoffTable

The Reason for Your Decision on Participation
The same as the last period.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as period 6.

PayoffTable

The Reason for Your Decision on Participation
To look at what will happen.

Your Payoff The Reason for Your Decision on Invest. Num.
706
PayoffTable

The Reason for Your Decision on Participation
Because of my failure at the last period.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected that my opponent's investment number would be between 6
and 8.

Because I expected that my opponent would invest about 10 units.

127

128

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

10

Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

PayoffTable

The Reason for Your Decision on Participation
Participation is less risky than non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the previous period.

PayoffTable

The Reason for Your Decision on Participation
Because I can get a reasonable payoff constantly by participation.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected that my opponent would choose 8.

PayoffTable

The Reason for Your Decision on Participation
I attempted to avoid the situation in which neither of us
participates in investment.

Your Payoff The Reason for Your Decision on Investment Number
2615

PayoffTable

I tried to get a large payoff and I also considered my opponent's
payoff.
The Reason for Your Decision on Participation
The same as the previous period.

Your Payoff The Reason for Your Decision on Investment Number
6478

I expected that my opponent would choose 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the pervious period. My payoff would be 6000-7000.

Your Payoff The Reason for Your Decision on Investment Number
2210

I made my opponent' payoff not large.

ID Number =3 , Male, Earnings = 2,530 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
My payoff is quite low when my opponent does not participate in investment.
I almost always used Payoff Table 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
4. If I can make my opponent's payoff as small as possible, it is fine that my payoff is moderate.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
At early periods, I expected that if I did not participate in investment, my opponent would invest 10 or 11 units to maximize
his payoff, and thus my payoff would be 7000 or 8000. However, my actual payoffs were lower than these expected value,
because my opponents chose smaller numbers. Or my payoff was 706 because my opponent did not participate ininvestment, either. Therefore I usually participated in investment at later periods.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I chose 7 because my payoff would be reasonable on average and my opponent's payoff would not be very high.
When your opponent did not participate in investment:
I chose 7 to make my opponent's payoff small.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
My opponents did not choose large investment numbers, neither did I. This is because they did not like that the payoff of
their opponent was higher than their own payoff. Most people invested 7 or 8 units. But by investing 7 or 8 units, I had
damage because my opponents did not participate in investment often. I think that investing 7 or 8 units is good when my
opponent participates in investment.

129

130

ID Number = 4, Male, Earnings = 2291 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

7

12

7234

Expecting my opponent would choose 12 or 13.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation´¯Your Payoff The Reason for Your Decision on Investment Number

Expecting many people would choose participation.
Your Payoff The Reason for Your Decision on Investment Number
6117
Payoff
Table

O
¯

Your
Opponent
O
¯

13

9

4383

You

Your
Opponent´¯

Payoff
Table

You

O
¯
13

Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
8The Reason for Your Decision on Participation
As a first step I chose participation.

13

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
Because I did not participate in investment at the last period.

Your Payoff The Reason for Your Decision on Investment Number

The Reason for Your Decision on Participation
Because of my success at period 1. I did the same thing.

Your Payoff The Reason for Your Decision on Investment Number
1631

My payoff is maximized by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
Because my payoff would be 8278 if my opponent participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I tried non-participation one more time.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

PayoffTable

The Reason for Your Decision on Participation
Because of my failures at periods 1-3.

Your Payoff The Reason for Your Decision on Investment Number
2658

My payoff is largest by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
Because of my failure in period 4.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Because non-participation did not work well.

Your Payoff The Reason for Your Decision on Investment Number
5681

Because I expected that my opponent would choose 8-11.

PayoffTable

The Reason for Your Decision on Participation
Because participation worked better than non-participation did.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff is largest by choosing this number.

PayoffTable

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
Because non-participation went well at period 9.

Your Payoff The Reason for Your Decision on Investment Number
4018

Your Payoff The Reason for Your Decision on Invest. Num.
4904

131

132

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation

Because my opponent did not choose 11 in the case ´ O (in which I did
not participate in investment, but my opponent does).
Your Payoff The Reason for Your Decision on Investment Number
6526

Because many people chose 7 or 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

ID Number = 4, Male, Earnings = 2291 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 1) in Practice.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I thought nobody would invest more than 11 units.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
At early periods I expected that if I did not participated in investment, then I could receive high payoffs because my
opponents would invest 11 units. However my opponents did not do so. Therefore I have participated in investment from a
middle.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
Because many people chose 7 or 8, I chose a number in an attempt to make my payoff as large as possible for such a number.
When your opponent did not participate in investment:
I chose the number maximizing my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Participate in investment at all periods. Choose 7 or 8 when the opponent participates in investment, and choose 11 when hedoes not.

133

134

ID Number =5 , Male, Earnings = 1889 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

Your
Opponent
O
¯

8

14

8885

I expected that my opponent would invest about 10 units, and chose theinvestment number maximizing my payoff under that expectation.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

7

10

Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You
´
¯

You
´
¯

Invest. Num.

Your
OpponentO¯

Your Payoff The Reason for Your Decision on Investment Number

Because I wanted to know what my opponent would do one more time.
Your Payoff The Reason for Your Decision on Investment Number
5688

Payoff
Table

Because my payoff would be at least 5000 if my opponent invests at least
9 units.
The Reason for Your Decision on Participation
Because I expected that my opponent would choose "participation" andwanted to get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
2299

Because I expected that my opponent would invest 13 units.

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

13

Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
7The Reason for Your Decision on Participation
Because I wanted to know what my opponent would do.

8

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.

PayoffTable

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
6117

Because I expected that my opponent would invest 10-13 units.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would choose participation, and I
wanted to get a reasonable payoff safely at the first period.

Your Payoff The Reason for Your Decision on Investment Number
706

I made a wrong estimate.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that my opponent would choose participation thistime, and I wanted to get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
706

I made a wrong estimate again.

PayoffTable

The Reason for Your Decision on Participation
Because of my failures at the previous two periods. I tried to recover myloss.

Your Payoff The Reason for Your Decision on Investment Number
2210

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Period 5 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to get a reasonable payoff this time.

Your Payoff The Reason for Your Decision on Investment Number
2210

My opponent expected that I would invest 11 units. Instead, I reduced
my opponent's payoff half by choosing this number.

PayoffTable

The Reason for Your Decision on Participation

My opponents at the previous four periods chose "non-participation,"and so my opponent at this period would
choose "participation."Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because my payoff is only 706 if neither of us participates in investment.

Your Payoff The Reason for Your Decision on Investment Number
7237

Because I expected that my opponent would invest 10 or 11 units.

PayoffTable

The Reason for Your Decision on Participation
Because I have to participate in investment once more, in order to recover
my loss.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected that my opponent would invest 9 or 10 units.

PayoffTable

The Reason for Your Decision on Participation
Because all would feel that participation is moreadvantageous, I counterplotted their plans.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I expected my payoff would be larger by choosing participation
than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
2210

My opponent expected that I would invest 11 units. Instead, I reduced
my opponent's payoff half by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
Because I expected my payoff would be larger by choosing participation
than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
6478

Because I expected my opponent would invest 9 or 10 units.

My opponent expected that I would invest 11 units. Instead, I reduced
my opponent's payoff half by choosing this number.

135

136

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

78

Period 13 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

PayoffTable

The Reason for Your Decision on Participation
Because I expected my payoff would be larger by choosing participation
than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected my opponent would invest 9 units.

PayoffTable

The Reason for Your Decision on Participation
Because I expected my payoff would be larger by choosing participation
than by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because my opponent would invest at most 8 units, I wanted
to get a higher payoff than my opponent does.

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to get a little higher payoff.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

ID Number =5 , Male, Earnings = 1889 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 3) in Actual Experiment(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I thought none would invest more than 12 units as soon as I looked at Payoff Table 1. Payoff tables 2 and 3 were notnecessary for me. I realized that investing 8 units would be best to receive the maximal payoff. By using Payoff Table 1, I
considered which investment number maximize my payoff for each investment number of my opponent, and I realized thatthe best choice is to invest 8 units.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

The Reason for Your Decision on Participation
I wanted to avoid the situation in which neither of us participates ininvestment and the payoff is 706.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected my opponent would invest 7 or 8 units.

PayoffTable

The Reason for Your Decision on Participation
I went on the gamble because this is the final period.

Your Payoff The Reason for Your Decision on Investment Number
4018

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Basically, participation in investment is less risky and safe. However, when I expect my opponent to participate ininvestment, non-participation in investment is more beneficial theoretically.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I invested 7 units because I expected that my opponent would invest 8 units. By investing 7 units instead of 8 units, mypayoff decreases only by 5, while my opponent's payoff decreases by at least 800.
When your opponent did not participate in investment:
Clearly my opponent intended to receive 8278 payoff, expecting that I would invest 11 units. I was angry about it.
Therefore, I invested 7 units so that my opponent's payoff was about the half of 8278.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
(No answer)

137

138

ID Number = 6, Male, Earnings = 2158 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

You
O
¯

Your
Opponent
O
¯

14

8

3692

Because I like this number.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You

PayoffTable

The Reason for Your Decision on Participation
As a first step I participated in investment to look at what would happen.

Your Payoff The Reason for Your Decision on Investment Number

As a first step I did not participate in investment to look atwhat would happen.
Your Payoff The Reason for Your Decision on Investment Number

13

6117
PayoffTable

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

8

24

20690

Because my opponent's payoff was larger than mine at practice 1.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

24

2

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.
0
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

0

The Reason for Your Decision on Participation
I participated in investment for a trial.

Your Payoff The Reason for Your Decision on Investment Number

I wanted to participate in investment and invest 24 units, because this ispractice.
Your Payoff The Reason for Your Decision on Investment Number
500

PayoffTable

I invested 24 units to make my opponent happy for a moment and shakehim.

The Reason for Your Decision on Participation
Because my opponent would participate in investment perhaps.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation

The payoffs of all subjects would increase by choosing participation,
instead of continuing to choose
non-participation.
Your Payoff The Reason for Your Decision on Investment Number
706

I do not want to lose a game against my opponent. Life is not so easy.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

116Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
117
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
118Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
118Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

11

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5504

My opponent would choose around 8, and I sacrificed my payoff bychoosing 11.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

This number would be the safest one which minimizes myloss.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6114

Choosing 11 would be best if the payoffs of all subjects are considered.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because I expected my opponent would choose 6-8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6765

Choosing 11 would be best if the payoffs of all subjects are considered.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6765

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6114

I have received reasonable payoffs recently, and so it matters little to me
which number should be chosen.

I hate my opponent's attitude. He only considers his own
payoff. Think of the payoffs of others.

139

140

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

0

8

8

Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
118Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Investment
9
NumberPeriod 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Investment
Number

8

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

Payoff
Table

PayoffTable

It would be best to punish my opponent by reducing his payoff even if
my payoff also decreases. Life is not so easy. What did my opponent
think? I prevented him from receiving a high payoff.

(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.

The Reason for Your Decision on Participation(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?

The same as the above.

I looked at Payoff Table 1.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would choose a number around 6-8. Ishould choose 8 to maximize my payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6765

Choosing 11 would be best if the payoffs of all subjects are considered.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Invest. Num.
2523

I chose 9 on sufferance, but I will never choose 11. There are many mean
fellows. I feel sick. I will never descend to such meanness.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Invest. Num.
2386

ID Number = 6, Male, Earnings = 2158 yen

This is the final period. How silly you are! But I never write 24. Feelingsick.

(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
It is desirable that the sum of my payoff and my opponent's payoff is as high as possible, unless my opponent is mean.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
At early periods I cared only about my payoff and did not participate in investment. But the others did not, either. Because
non-participation was not beneficial as a whole, I decided to participate in investment.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I considered the sum of my payoff and my opponent's payoff. Perhaps my opponent would choose around 6, 7, or 8, and so
I chose around 11.
When your opponent did not participate in investment:
I invested 0 units so that both payoffs were 706. I was very angry about my opponent because he cared only about his own
payoff. But at later periods I invested some units out of pity.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
We should make investment decisions to maximize the sum of my payoff and my opponent's payoff. I am irritated whenmy opponent considers only his own payoff.

141

142

ID Number = 7, Female, Earnings = 2620 yen
Practice 1

Participation
in investment

Investment
NumberPractice 2

Participation
in investment
Investment
NumberPractice 3

Participation
in investment
Invest. Num.
Practice 4

You
O
¯

12

You

Your
OpponentO¯

7

The Reason for Your Decision on Participation

Because my opponent would not participate in investment to see what
happens or he would invest a small amount at thefirst time.
Your Payoff The Reason for Your Decision on Invest. Num.
3792

O
¯
3

9

4039

Because my opponent would invest a relatively large amount.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

6

12

You

Participation
in investmentO¯

Invest. Num.

7

10Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
11

Payoff
Table

Because my opponent would invest a small amount to look at what
would happen.

Your
OpponentO¯

Your
OpponentO¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
If I do not participate in investment, but my opponent does, my opponent
would definitely choose 13.

Your Payoff The Reason for Your Decision on Invest. Num.

My payoff would be limited to some degree if I do not participate ininvestment.
Your Payoff The Reason for Your Decision on Investment Number
7172

PayoffTable

My opponent would invest 7-9 units of money, and I chose
this number to receive a reasonable payoff safely under that expectation.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5688

Because I expected that my opponent would choose a large investment
number as at practice 3.

PayoffTable

The Reason for Your Decision on Participation

If I do not participate in investment, but my opponent does,
my opponent would invest 11 units of money to maximize his payoff.
(Whether or not my opponent participates in investment is left to chance.)Your Payoff The Reason for Your Decision on Investment Number

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

67

Period 4 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

706
PayoffTable

The Reason for Your Decision on Participation
Because I recognized some persons have the similar idea.

Your Payoff The Reason for Your Decision on Investment Number
2658

I chose the number which maximizes my payoff because I
knew my opponent did not participate in investment.

143

Invest. Num.
7
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

5

PayoffTable

The Reason for Your Decision on Participation

There is good probability that my opponent would choose
non-participation. But I do not like the case in which my
payoff is only 706.
Your Payoff The Reason for Your Decision on Investment Number
6339

Because my opponent would invest a secure number when heparticipates in investment.

PayoffTable

The Reason for Your Decision on Participation
Because I expected that someone would participate in investment toavoid falling together.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
2658 is better than 706.

Your Payoff The Reason for Your Decision on Investment Number
7237

I expected that my opponent would invest 6-9 units.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I would like to have a bet one more time.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Because I perceived that my opponent might be fool (the opponent at thelast period did not choose the number maximizing his own payoff).

Your Payoff The Reason for Your Decision on Investment Number
4762

I expected that my opponent would choose 7-9.

144Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
69Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
77
NumberPeriod 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

PayoffTable

The Reason for Your Decision on Participation
Because of the reasons at periods 5 and 9.

Your Payoff The Reason for Your Decision on Investment Number
8209

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

PayoffTable

The same as the above.

The Reason for Your Decision on Participation
The same as the above.

ID Number = 7, Female, Earnings = 2620 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 2) in Practice(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
By choosing around 7-9, I can constantly get 6,000-7,000 points if my opponent also takes a safe strategy. There would be
little people who invest more than 9 units. All of us would receive similar payoffs if we just understand the rules.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
It is desirable that my payoff is high and the difference between my payoff and my opponent's is large.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:

7340

The same as the above.

If I do not participate in investment, then it is possible that my opponent may not either, and both may get low payoffs.
Also, I expected a high payoff in the case ´O (in which I did not participate in investment, but my opponent did). However,in that case, my payoff was not so high, because my opponent thought that if he could make his opponent's payoff as small
as possible, it was fine that his payoff was moderate.

PayoffTable

The Reason for Your Decision on Participation(6) How did you choose your investment number when you participated in investment?

Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

When your opponent participated in investment:
I took a safe strategy (chose around 7-9), because of the reason specified in (3).

7340

The same as the above.

When your opponent did not participate in investment:

PayoffTable

The Reason for Your Decision on Participation

I tried to maximize my own payoff, regardless of my opponent's payoff.

The same as the above.

(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
2658

I chose the number maximizing my payoff.

145

One should participate in investment if his prime concern is his own payoff. I would like to avoid the case where neither of
us participates in investment and both receive low payoffs. Investing more than 9 units would just make my opponent
happy, because my payoff is not high, while my opponent's payoff is quite high.

146

ID Number = 8, Male, Earnings = 2476 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

12

6

3400

Because choosing this number would make less mistake.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

4

10

5095

I wanted to try several numbers.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

24

8

500

I wanted to try several numbers.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O¯
13

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
9
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

6

PayoffTable

The Reason for Your Decision on Participation
Because participation would be more beneficial than non-participation.

Your Payoff The Reason for Your Decision on Investment Number

Participation would be more beneficial than non-participation
Your Payoff The Reason for Your Decision on Investment Number

I wanted to try several numbers by participating in investment.
Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
1631

Choosing this number is most profitable.

PayoffTable

The Reason for Your Decision on Participation
Hopefully my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5907
PayoffTable

The Reason for Your Decision on Participation
Because there is some probability that my payoff will be large.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
66
Period 5 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 6 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
97
Period 8 of the Actual Experiment
w
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

9

6

PayoffTable

The Reason for Your Decision on Participation
I wanted to get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
5515

Choosing this number would be profitable.

PayoffTable

The Reason for Your Decision on Participation
Hopefully my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I want to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
6481

I want to get a high payoff.

PayoffTable

The Reason for Your Decision on Participation
I want to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because my opponent would choose a number between 6 and 8.

PayoffTable

The Reason for Your Decision on Participation
Hopefully my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

My opponent would choose 6 or 7.

PayoffTable

The Reason for Your Decision on Participation
I wish that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
5765

My opponent would choose 8 or 9.

Your Payoff The Reason for Your Decision on Investment Number
5766

Choosing this number would be profitable.

147

148

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.
67
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

98

PayoffTable

The Reason for Your Decision on Participation
Participation would be more profitable than non-participation.

Your Payoff The Reason for Your Decision on Investment Number
2210

I did not give my opponent a large payoff.

PayoffTable

The Reason for Your Decision on Participation
I wish that my opponent would also choose participation.

Your
Payoff
6339
PayoffTable

ID Number = 8, Male, Earnings = 2476 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?

I wish that my opponent would choose 8.

First I thought that the case ´ O where I did not participate in investment, but my opponent did would be most beneficial tome. In this case, however, my opponents rather reduced my payoff than maximized their own payoffs. Therefore I foundthat the case O O where both participate in investment was most beneficial to me in a middle of the experiment.

The Reason for Your Decision on Participation(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?

The Reason for Your Decision on Investment Number

Participation would be more profitable than non-participation.
Your Payoff The Reason for Your Decision on Investment Number
6478

Choosing 7 would be most profitable.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

4. If I can make my opponent's payoff as small as possible, it is fine that my payoff is moderate.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:

7340

Choosing 7 would make little mistake.

First I thought that the case where I did not participate in investment, but my opponent did would be best for me. However,I found that non-participation was not so profitable and very risky in a middle of the experiment, and so I participated ininvestment at all the rest of periods.

PayoffTable

The Reason for Your Decision on Participation(6) How did you choose your investment number when you participated in investment?

The same as the above.

When your opponent participated in investment:

Your Payoff The Reason for Your Decision on Investment NumberYour Payoff The Reason for Your Decision on Investment Number
7250

There is some probability that my payoff is large.

I chose 6-8, because my payoff was reasonable and my opponent's payoff was not very high.
When your opponent did not participate in investment:
I rather reduced my opponent's payoff than maximized my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
It would be best to participate in investment and choose around 6-8 at all periods, because my payoff would be reasonably
high and be similar to my opponent's payoff.

149

150

ID Number = 9, Male, Earnings = 2955 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

9

12

7085

Because I expected that my opponent would choose the average
investment number (12).

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You
O
¯

Your
Opponent
´
¯

8
You
O
¯
2

Your
OpponentO¯
10Invest. Num.
7
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
7Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation
Because it is clear that there is a big loss when both choose 'nonparticipation'.

Your Payoff The Reason for Your Decision on Investment Number

I took a bleak.
Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.

PayoffTable

7

7

PayoffTable

The Reason for Your Decision on Participation
Because of my failure at practice period 2.

Your Payoff The Reason for Your Decision on Investment Number
1282

I do not like to write the number 13 simply (to maximize my payoff).

PayoffTable

The Reason for Your Decision on Participation'Non-participation' is not a fun. Because this is practice, I would like tohave a fun.

Your Payoff The Reason for Your Decision on Investment Number
4393

PayoffTable

I wanted to see what would happen if I choose a wild number before theactual experiment.

The Reason for Your Decision on Participation
Everyone would participate in investment, because there is enough time(ten minutes) to consider. I took a counterplot.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Because I was revenged for non-participation at period 1.

Your Payoff The Reason for Your Decision on Investment Number
2210

If I choose the number maximizing my payoff, my opponent's payoff isvery large. I am angry about it.

PayoffTable

The Reason for Your Decision on Participation
Choosing non-participation is boring in this game.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
5
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

84Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

11

PayoffTable

The Reason for Your Decision on Participation
It is efficient for me to participate in investment as far as myopponent also does.

Your Payoff The Reason for Your Decision on Investment Number
7345

Everyone seems to be experienced and so my opponent would choose 69.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

If I choose the number maximizing my payoff, my opponent's payoff isvery large. I am angry about it.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

My opponent would choose 7 or 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6115

To reduce my opponent's payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4420

Choosing this number would result in a reasonable payoff safely (I halt
an attack on my opponent).

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
10339

Because it would be most efficient to choose this number as at period 9.

Your Payoff The Reason for Your Decision on Investment Number
6478

My opponent would choose 8-10.

151

152

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

78

Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

Payoff
Table

Everyone seems to settle down to choosing 7 or 8. Because I will nevermeet the same person, it is interesting to choose 7 to spite my opponent.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above. Spiting my opponent means reducing his payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340
PayoffTable

The same as the above.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

ID Number = 9, Male, Earnings = 2,995 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
Payoff tables 2 and 3 are little meaningful. I almost always the north-west side of Payoff Table 1, because none would
choose a large investment number.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
It is desirable that my opponent's payoff is not larger than my payoff, and my payoff is moderate.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
First I intended to give my opponent a metal blow by choosing non-participation. However, I found it meaningless at early
periods.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I tried to choose the number that is smaller than my opponent's number by 1. This is because my payoff is larger than myopponent's by doing so.
When your opponent did not participate in investment:
My opponent tended to receive a high payoff. I tried to reduce my opponent's payoff as far as my payoff did not decreasemuch.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Non-participation in investment often results in a loss, because my opponent may not participate in investment, or my
opponent can control my payoff when he participates in investment. Concerning investment numbers, it is important tobalance my investment number and my opponent's.

153

154

ID Number = 10, Male, Earnings = 3199 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

Your
Opponent
O
¯

9

12

7085

Because by choosing this number, I would surely receive a reasonablepayoff.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investmentO¯

Invest. Num.
Practice 3

7

The Reason for Your Decision on Participation
Because I wanted to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number

Participation would be more profitable than non-participation.
Your Payoff The Reason for Your Decision on Investment Number
1148

I did not like that my opponent got a large payoff.

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

9

13

7844

From my experience at practice 1. Then I got a large payoff.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment
Invest. Num.

You

Payoff
Table

´
¯

0

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

8

Because I expected that my opponent would participate in investment.
Your Payoff The Reason for Your Decision on Investment Number

I would like to choose 'non-participation' once at least.
Your Payoff The Reason for Your Decision on Investment Number
500

PayoffTable

The Reason for Your Decision on Participation
Because I failed by choosing non-participation at practice 4.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected that my opponent would choose a similar number.

PayoffTable

The Reason for Your Decision on Participation
Because of my success at the last period.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
At period 2 my opponent did not participate in investment
and I felt mortified.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
11
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
79Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6478

I expected that my opponent would choose around 8.

PayoffTable

The Reason for Your Decision on Participation
I will not choose 0 if my opponent does not participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
2386

Not in particular.

PayoffTable

The Reason for Your Decision on Participation
It is significant to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
10339

Not in particular.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8271
PayoffTable

7 is a lucky number.
The Reason for Your Decision on Participation
I will continue to participate in investment from now on.

Your Payoff The Reason for Your Decision on Investment Number
7340

I will continue to choose 7.

PayoffTable

The Reason for Your Decision on Participation
Because I like to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I like the number 7.

PayoffTable

The Reason for Your Decision on Participation
It would be profitable to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6478

Choosing 7 would be reasonable.

Your Payoff The Reason for Your Decision on Investment Number
4904

155

156

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
78
NumberPeriod 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
77
NumberPeriod 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

6

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected that my opponent would choose about 7.

PayoffTable

The Reason for Your Decision on Participation
Because I like to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6478

Because my opponent would choose 6-9.

PayoffTable

The Reason for Your Decision on Participation
Because my opponent would also participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7340

Payoff
Table

Because my opponent would choose around 7.

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Invest. Num.
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

ID Number = 10, Male, Earnings = 3199 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
Not in particular.
I used Payoff Table 1 when both I and my opponent participated in investment. I used both Payoff Table 2 and Payoff Table
3, when my opponent participated in investment, but I did.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Participation would be good both for me and for my opponent (if my opponent also participates in investment).
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:

The same as the above.
Your Payoff The Reason for Your Decision on Invest. Num.
5766

I found choosing 8 would be better than choosing 7.

I always chose 7. But I think I could receive higher payoffs by choosing 8 instead of 7.
When your opponent did not participate in investment:
At the first time I chose the number maximizing my payoff. At the second time I chose a smaller number so that my
opponent did not get a high payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
I think that I should care only about my payoff and always invest 8 units. Also, non-participation should not be chosen,because it makes my opponent feel uncomfortable and I may not receive a high payoff.

157

158

ID Number = 11, Male, Earnings = 2633 yen
Practice 1

Participation
in investment

You
´
¯

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation
I did not participate in investment because everyone would participate ininvestment at the first time.

Your Payoff The Reason for Your Decision on Investment Number
Investment
NumberPractice 2

Participation
in investment
Invest. Num.
Practice 3

You
´
¯

You

6

1416

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation
Something tells me that non-participation would be more profitable thanparticipation.

1815
PayoffTable

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

11

7

3918

Because my opponent's investment number would be small.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investmentO¯

Invest. Num.

87Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Invest. Num.

80

The Reason for Your Decision on Participation
I feel non-participation would make both worse-off.

Your Payoff The Reason for Your Decision on Investment Number

Participation would be more profitable than non-participation.
Your Payoff The Reason for Your Decision on Investment Number
3915

Payoff
Table

Because I expected that my opponent's investment number would be 6-8.

The Reason for Your Decision on Participation
Non-participation is never profitable. My opponent would participate ininvestment if he is not silly.

Your Payoff The Reason for Your Decision on Investment Number
2210

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.
7
7
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Payoff
Table

PayoffTable

This person, No. 20, did not understand the situation at alleven after 4 periods of practice. Choosing '7' will teach him a good
lesson.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2386

I found that choosing '8' would be most profitable to the average
investment numbers of my opponents, 6-8, over 4 periods of practice.

159

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

The Reason for Your Decision on Participation

The case O O is better than the case ´ O. Clearly, if both invest 6-8 units,
both receive reasonable payoffs and can avoid big losses.
Your Payoff The Reason for Your Decision on Investment Number
6478

Choosing this number is safe.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

Why did not my opponent participate in investment? Someone might notparticipate in investment at the latter periods with psychological warfare.
But this is still the begging of the game. Why did not he choose aprofitable action? You should make a profit rather than enjoy yourself.
Did you understand it?

PayoffTable

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number

7

Your
OpponentO¯

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

The case ´ O is more profitable than the case ´ O, but the case O O is mostprofitable.
Your Payoff The Reason for Your Decision on Investment Number
7345

Choosing this number is safe and most reasonable. If both of us choose 7
or 8 without any serious consideration, we can get good profits with lesseffort.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

No other choice.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345(8, 8) would be settled.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

If you invest 0, your opponent does not more than 8. I cannot see why
my opponent did not understand it.

160Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

No outcome other than (8, 8) will occur.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

Why are you so silly, No. 4? Think about the meaning of investment.
The average investment number in the market has already been known.

PayoffTable

The Reason for Your Decision on Participation

The person who does not participate in investment must be foolish. Why
should I participate in investment? Because I can
increase my own money.
Your Payoff The Reason for Your Decision on Investment Number
6526

If my opponent invest in an attempt to maximize his profit, he should
write 8 because the average investment number is 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 11, Male, Earnings = 2633 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I used only Payoff Table 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
The case O O (where both I and my opponent participate in investment) is more beneficial to both me and my opponent thanthe case O´ (in which I participate in investment, but my opponent does not) and the case ´O (in which my opponent
participates in investment, but I do not). This is clear from the fact that the average investment number is around 6-8. It is
hard to find the reason why non-participation is more advantageous than participation.
(6) How did you choose your investment number when you participated in investment?

7345

The same as the above.

When your opponent participated in investment:

PayoffTable

The Reason for Your Decision on Participation

The average investment number was around 6-8. Thus I almost always chose 8 so that both my payoff and my opponent's
payoff were high.

The same as the above.
Your Payoff The Reason for Your Decision on Invest. Num.
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

When your opponent did not participate in investment:
I chose 7 to receive a moderate payoff. I also intended my opponent to realize the disadvantage of non-participation.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
First of all, the purpose of investment is to increase my own property. It is not desirable to compete with others and trip
others up because it may lead to my own loss. It is good to participate in investment positively in order to capture the stateof the market. By investing 8 units, my payoff is highest for the average investment number 6-8. If my opponent also
realizes this fact, both of us receive high payoffs.

The same as the above.
Your Payoff The Reason for Your Decision on Invest. Num.
6526

The same as the above.

161

162

ID Number = 12, Male, Earnings = 3284 yen
Practice 1

Participation
in investment
Invest.Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

You
O
¯

Your
Opponent
O
¯

7

10

5688

From the payoff tables, I would get a reasonable payoff on average byinvesting this amount.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You
O
¯

Invest. Num.
Practice 40Invest. Num.

You
O
¯

Your
Opponent´¯

YourOpponent´¯

7Your Payoff The Reason for Your Decision on Investment Number

I would like to see how my opponent behaves when I do not participate
in investment. (Perhaps he would choose 13.)Your Payoff The Reason for Your Decision on Investment Number

Invest. Num.
11
Period 2 of the Actual Experiment
w
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
6

PayoffTable

8

The Reason for Your Decision on Participation
The same as practice 1.

Your Payoff The Reason for Your Decision on Investment Number
500

To prevent my opponent from getting a large payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as practice 1.

Your Payoff The Reason for Your Decision on Investment Number
1148

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.

The Reason for Your Decision on Participation
I would like to see how my opponent behaves when I participate ininvestment (because this is practice).

500

Participation
in investment

Participation
in investment

Payoff
Table

PayoffTable

To prevent my opponent from getting a large payoff.

The Reason for Your Decision on Participation
Because I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
2658

Choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
It is not fun to choose non-participation.

Your Payoff The Reason for Your Decision on Investment Number
5681

Because my payoff would be high on average by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
Because my opponent's payoff is surely small if I do not participate ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
7237

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
811Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

87Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526
Payoff
Table

Because my payoff as well as my payoff would be high on average.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
10173

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

If I do not participate in investment, my opponent's payoff is small. Also
I risk my payoff because the case ´ ´ might happen.
Your Payoff The Reason for Your Decision on Investment Number
6526

Both I and my opponent would receive high payoffs on
average. (Choosing 8 is better than choosing 6 or 7 if my opponent
chooses 6, 7, or 8.)

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

Because my payoff would be high on average.

163

164

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345
PayoffTable

The same as the above.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

ID Number = 12, Male, Earnings = 3284 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I always used Payoff Table 1 to make decisions.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
Non-participation always makes my opponent's payoff low.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
Basically I chose 8.
When your opponent did not participate in investment:
I chose 11 to maximize my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
By Payoff Table 1, I found my best investment number for each investment number of my opponent (11 for 0, 11 for 1, ..., 8
for 8, ..., 0 for 24). When both I and my opponent choose 8, I choose my best number for the number he chooses, and my
opponent also chooses his best number for the number I choose. This situation would be less risky for both. Therefore I
think choosing 8 is the best choice.

165

166

ID Number = 13, Male, Earnings = 2798 yen
Practice 1

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

8

12

7206

By looking at the supplemental tables 1-2, I thought there is highprobability that choosing this number will make my payoff high.

You

PayoffTable

The Reason for Your Decision on Participation

Practice 2

You

PayoffTable

The Reason for Your Decision on Participation
I tried participation because this is practice.

Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 3

10

4

2708

I expected that everyone would reduce his investment number.

You

PayoffTable

The Reason for Your Decision on Participation

To get used to this experiment. The same as period 1.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

7

6

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯Your Payoff The Reason for Your Decision on Investment Number
Invest. Num.
7
6
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

10

10

5596

My opponent would choose a number between 3 and 10.

Invest. Num.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯Participation
in investment´¯

Invest. Num.

Your Payoff The Reason for Your Decision on Investment Number

To look at what happens.
Your Payoff The Reason for Your Decision on Investment Number

8

6

500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.
11
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

It would be disadvantageous to declare non-participation.

6

7

PayoffTable

The Reason for Your Decision on Participation

I would get 8000 if I do not participate in investment, but suchan action is risky at the first time. I want to try non-participation after
accumulating enough payoffs.
Your Payoff The Reason for Your Decision on Investment Number
2658

The only thing I can do is to choose 11 to receive the highest payoff.

PayoffTable

The Reason for Your Decision on Participation
I had better looking at how my opponent behaves.

Invest. Num.
86Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯Your Payoff The Reason for Your Decision on Investment Number6339

I am happy if my opponent chooses 8 or 9. I hope so.

Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

167

8

7

PayoffTable

The Reason for Your Decision on Participation

Investing nothing (non-participation) is not a good choice at this stage. I
will do it only after my payoff per period has been constantly at least
5000 (my goal is to get at least 5000 points per period).
Your Payoff The Reason for Your Decision on Investment Number
5681

My opponent would choose a number between 5 and 11. Choosing 7 issafe both when my opponent's number is 5 andwhen it is 11.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I continue to participate in investment until my payoff per period has
been constantly at least 5000.

Your Payoff The Reason for Your Decision on Investment Number
5766

Choosing this number would be best if my opponent chooses a number
between 6 and 8. I can get 5000 points even if he chooses 5.

PayoffTable

The Reason for Your Decision on Participation

At previous three periods, my opponents chose participation andinvested 6 units. My opponent at this period would also choose
participation.
Your Payoff The Reason for Your Decision on Investment Number
5766

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I get 8278 points in the case 0-11 and 7345 points in the case
8-8. I prefer the latter to the former.

Your Payoff The Reason for Your Decision on Investment Number
7345

Choosing 8 is good if my opponent chooses a number between 6 and 9.

PayoffTable

The Reason for Your Decision on Participation
If my opponent is a normal person, he would invest 11 units, and mypayoff would be 8278 points.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I would like to get reasonable payoffs constantly.

Your Payoff The Reason for Your Decision on Investment Number
6526

My opponent would choose a number between 6 and 8.

168Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
83
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
9
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation

ID Number = 13, Male, Earnings = 2798 yen(1) Did you understand the rules of the experiment?

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
3831

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I think only Payoff Table 1 is sufficient.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.

Safety is important for me.
Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
If I do not participate in investment, my payoff would beeither 706 or 8278. The gap between them is too large.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
This is a gamble. Everyone would not participate ininvestment at the final period.

Your Payoff The Reason for Your Decision on Investment Number
5907
PayoffTable

The Reason for Your Decision on Participation

There is high probability that my opponent will choose non-participation(´).
Your Payoff The Reason for Your Decision on Investment Number
7345

My opponent would choose a number between 6 and 8.

(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
I did not participate in investment only if I went a gamble to get a high payoff.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
My opponents almost always selected 6-8 only. Thus I always selected 8 to receive a high payoff for such numbers.
When your opponent did not participate in investment:
I invested 11 units so that my payoff is as high as possible.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
(1) Never participate in investment and get 8278 points at several periods.
Or(2) Invest 8 units at all periods.

169

170

ID Number = 14, Female, Earnings = 2538 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

12

9

4663

As a first step I chose a middle number.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

9

3

2272

I expected that my opponent would invest at least 10 units.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

6

7

3610

I expected that my opponent would invest at least 10 units.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

3

10

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

0

PayoffTable

The Reason for Your Decision on Participation
As a first step I participated in investment.

Your Payoff The Reason for Your Decision on Investment Number

Because I wanted to participate in investment.
Your Payoff The Reason for Your Decision on Investment Number

Because I wanted to participate in investment.
Your Payoff The Reason for Your Decision on Investment Number

My expectation proved wrong, but it is interesting.
Your Payoff The Reason for Your Decision on Investment Number
4769

PayoffTable

I expected that my opponent would invest at least 7 units.

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 5 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
97
Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

7

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6481
PayoffTable

I expected that my opponent would invest at least 6 units.
The Reason for Your Decision on Participation
I expected that my opponent would participate in investment and invest
11 units.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number6339

I expected that my opponent would invest at least 6 units.

Your Payoff The Reason for Your Decision on Investment Number
706

171

172

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest at least 6 units.

PayoffTable

The Reason for Your Decision on Participation
I expected that my opponent would participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected that my opponent would invest at least 6 units.

ID Number = 14, Female, Earnings = 2538 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I looked at Payoff Table 1 and Supplemental Payoff Table 1-2.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
I did not participate in investment at early periods. It was interesting to see the various responses of my opponents when I
chose non-participation.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I chose 6-9, because both my payoff and my opponent's payoff were reasonably high.
When your opponent did not participate in investment:
I chose 11, because I got the highest payoff. I expected my opponent would also choose 11 when I did not participate ininvestment, but my opponent did. However, this expectation did not come true.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
The best choice would be to participate in investment and choose an investment number so that both I and my opponent get
reasonably high payoffs. This is because it was difficult to expect my opponent's investment number when I did notparticipate in investment.

173

174

ID Number =15, Male, Earnings = 3118 yen
Practice 1

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

7

9

Practice 2

Participation
in investment
Invest. Num.
Practice 3

You

You
O
¯

Your
Opponent´¯

13Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

80

Practice 4

Participation
in investment

You

You
´
¯

Your
Opponent´¯

Invest. Num.

78

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation

I thought my payoff would be higher by choosing
participation than by doing non-participation when looking
at payoff tables.
Your Payoff The Reason for Your Decision on Investment Number
5000

PayoffTable

I expected that my opponent would choose 7 or 8. I expected from thepayoff tables that choosing this number would be most beneficial underthat expectation.
The Reason for Your Decision on Participation
From my success in practice 1.

Your Payoff The Reason for Your Decision on Investment Number
1631

Because choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
My payoff would be higher by choosing participation than by choosing
non-participation.

Your Payoff The Reason for Your Decision on Investment Number
1282

Payoff
Table

Because choosing this number would be most beneficial under the
expectation that my opponent would choose 7 or 8.
The Reason for Your Decision on Participation
I thought it is interesting to choose non-participation by observing theresults at practice 2 and 3.

Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

PayoffTable

11

PayoffTable

The Reason for Your Decision on Participation
First of all, I will participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected my opponent to choose an investment number
between 7 and 9.

PayoffTable

The Reason for Your Decision on Participation
Because my payoff would be higher by choosing participation than bychoosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because choosing this number maximizes my payoff.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

79Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
5
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

175

7

5

6

PayoffTable

The Reason for Your Decision on Participation
Because my failure at period 2 of the actual experiment.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Because the result at period 3 was not good.

Your Payoff The Reason for Your Decision on Investment Number
6478

Because I expected my opponent to choose an investment number
between 7 and 9.

PayoffTable

The Reason for Your Decision on Participation
Because my payoff would be better by participating in investment thanby not participating.

Your Payoff The Reason for Your Decision on Investment Number
8271

I expected my opponent to choose an investment number between 7 and9.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4950

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5272

Because I expected my opponent to choose around 6.

176

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
79Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

8

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected my opponent to choose a number between 7 and 9.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8271

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number

ID Number =15, Male, Earnings = 3118 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I mainly took a look at Payoff Table 1 when I decided my investment number. I sometimes used Payoff Table 3.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Before the actual experiment, I decided to choose non-participation only one time.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I selected a number between 7 and 9, because I expected my opponent would select a number between 7 and 9 by looking at
Payoff Table 1.
When your opponent did not participate in investment:

7340

The same as the above.

I chose the number maximizing my payoff.

PayoffTable

The Reason for Your Decision on Participation(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

177

I think it is best to participate in investment at all periods, because my payoff with non-participation would be smaller thanthat with participation. Further I think the best investment number is 7, because my opponent would also choose a number
between 7 and 9 many times.

178

ID Number = 16, Male, Earnings = 3065 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You
O
¯

Your
Opponent
O
¯

9

12

7085

My opponent would invest about half of 24 units. Under thisexpectation, my payoff is large by investing about 9 units.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

10

7

3981

I chose a number close to half of 24 and wanted to look at what would
happen.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13
You
´
¯

Invest. Num.

Your
Opponent
O
¯
7

8

7

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

6

The Reason for Your Decision on Participation
As a first step I participated in investment.

Your Payoff The Reason for Your Decision on Investment Number

I attempted to get a large payoff in the case where both participate ininvestment.
Your Payoff The Reason for Your Decision on Investment Number

I would like to avoid the risk that nether participates in investment.
Your Payoff The Reason for Your Decision on Investment Number
1631

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

Payoff
Table

PayoffTable

To maximize my payoff in the case O ´.
The Reason for Your Decision on Participation
Hopefully my opponent would participate in investment and I would geta large payoff by not participating in investment.

Your Payoff The Reason for Your Decision on Investment Number
1815

PayoffTable

The Reason for Your Decision on Participation
It would be best that both participate in investment and get reasonablepayoffs each other.

Your Payoff The Reason for Your Decision on Investment Number
6526

PayoffTable

My opponent would choose around 10. Under that expectation, I would
receive a reasonably high payoff by choosing this number.
The Reason for Your Decision on Participation

Both my opponent and I would like to avoid the risky case (´´) where
neither of us participates in investment.
Your Payoff The Reason for Your Decision on Investment Number
5681

I chose a relatively small number to get a reasonably high payoff evenwhen my opponent chose the same strategy.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

87Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
79Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

179

8

8

11

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2386

I did not permit only my opponent to enjoy a high payoff. So I chose 8 toreduce his payoff, although my payoff also decreases.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected my opponent to choose 7 or 8.

PayoffTable

The Reason for Your Decision on Participation
Because I would like to avoid the risk that neither of us participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
7345
PayoffTable

I expected my opponent to invest 7 or 8 units.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest 7 or 8 units as I did,and he would take a safe action, but not went on the gamble.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8271

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
10173

The same as the above.

180

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

Invest. Num.
87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment
¯
¯
7

8

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

Payoff
Table

PayoffTable

My opponent would expect me to invest 11 units. But I prevent him fromgetting a high payoff.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would take an action similar to mine.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210
PayoffTable

The same as period 10.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected that my opponent would invest around 7, 8, or 9 units as I did.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

ID Number = 16, Male, Earnings = 3065 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
The payoff changes variously, depending on my investment number as well as my opponent's.
I referred to Payoff Table 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
5. If my payoff is the same as my opponent's payoff, I do not care about the absolute value of my payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
There is a heavy loss if neither of us participates in investment. Rather it would be better to participate in investment at a ll
periods and get reasonable payoffs steadily.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I expected my opponent would also do behavior similar to mine, and I chose a number so that both of us got reasonably
high payoffs.
When your opponent did not participate in investment:
I lose heavily if my opponent does not participate in investment. If I try to maximize my own payoff, I play right into my
opponent's hands and he gets a high payoff. Therefore I reduced my investment number so that the decrease in my payoff
was smaller than the decrease in my opponent's payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

The same as the above.

It is good to participate in investment as many times as possible in order to cooperate with my opponent. I should try toenlarge mutual benefit, not my own payoff only. If both of us choose investment numbers such that our payoffs are close,
we will reach an agreement and there will be no battle.

181

182

ID Number = 17, Male, Earnings = 3021 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

12

8

4213

Because I expected that nobody would invest a large amount.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13
You
´
¯

Your
OpponentO¯

Your Payoff The Reason for Your Decision on Investment Number

I wanted to try participation one more time.
Your Payoff The Reason for Your Decision on Investment Number
1631

Because my opponent did not participate in investment.

PayoffTable

The Reason for Your Decision on Participation
Non-participation would be more profitable thanparticipation.

Your Payoff The Reason for Your Decision on Investment Number
6117
Payoff
Table

O
¯

Your
Opponent
O
¯

7

8

You

Invest. Num.
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment
¯
¯
6

9

The Reason for Your Decision on Participation
First of all I tried participation.

13

Period 1 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
It is more fun to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
4368

Payoff
Table

Because investing this amount would be most profitable on average.

The Reason for Your Decision on Participation
Because I expected that everybody would participate in investment at thefirst period.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I felt that my opponent would participate in investment andinvest a large amount.

Your Payoff The Reason for Your Decision on Investment Number
6339

Because I felt that my opponent would invest a large amount.

PayoffTable

The Reason for Your Decision on Participation
Because participation would be efficient.

Your Payoff The Reason for Your Decision on Investment Number
8209

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
66
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
97
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
89Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
77
NumberPeriod 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

7

PayoffTable

The Reason for Your Decision on Participation
I will continue to participate in investment for a while.

Your Payoff The Reason for Your Decision on Investment Number
5515

Because investing this amount is efficient.

PayoffTable

The Reason for Your Decision on Participation
I will continue to participate in investment for a while.

Your Payoff The Reason for Your Decision on Investment Number
6481

Because I expected my opponent to invest a small amount.

PayoffTable

The Reason for Your Decision on Participation
I will participate in investment a little longer.

Your Payoff The Reason for Your Decision on Investment Number
8225

Because my opponent would invest around 6 or 7 units.

PayoffTable

The Reason for Your Decision on Participation
I still participated in investment.

Your Payoff The Reason for Your Decision on Investment Number
6478

My opponent would invest a relatively large amount.

PayoffTable

The Reason for Your Decision on Participation
I challenged non-participation although it was risky.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I am obstinate.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
I finally recognized that non-participation would not pay me.

Your Payoff The Reason for Your Decision on Investment Number6339

I expected my opponent to invest a large amount.

Because I felt my opponent would invest a large amount.

183

184

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
811Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

8

PayoffTable

The Reason for Your Decision on Participation
Wishing I can get a high payoff this time.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because most of my opponents have invested around 6 or 7 units.

PayoffTable

The Reason for Your Decision on Participation
Because 'non-participation' is too risky.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because most of my opponents have invested around 6 or 7 units.

PayoffTable

The Reason for Your Decision on Participation
It would be risky if I did not participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
10173

Because I wanted a high payoff.

PayoffTable

The Reason for Your Decision on Participation
Participation is safer than non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7237

Hopefully my opponent would invest a large amount.

PayoffTable

The Reason for Your Decision on Participation
Off course I participated in investment because this is the final period.

Your Payoff The Reason for Your Decision on Investment Number
7237

Hopefully my opponent would invest a large amount again.

ID Number = 17, Male, Earnings = 3021 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I took a look at Payoff Table 1 only.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
I did not participate in investment a few times, because I could receive a high payoff if I did not participate in investment,
but my opponent did.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I expected my opponent's investment number, and then I chose the investment number maximizing my payoff for that
expected number.
When your opponent did not participate in investment:
I chose a number so as to make my payoff as high as possible.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
The best choice: 6-8
The reason: Because everyone usually invests around 6-8 units, my payoff may become small if I invest larger units or
smaller units.
The risk for non-participation is so high that everybody will participate in investment at later periods. In addition, it would
be better to submit a participation card and an investment card simultaneously.

185

186

ID Number = 18, Male, Earnings = 2430 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

10

7

3981

Choosing this number is profitable when my opponent's investment
number is small.

You

PayoffTable

The Reason for Your Decision on Participation

Because this is the first time.
Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 3

6

9

4850

My opponent's payoff is at most 3520 when I choose this number.

You

PayoffTable

The Reason for Your Decision on Participation

Because my payoff at the previous period was bad.
Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

0

8

2299

I always get a payoff which is better than my opponent's.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment
Invest. Num.

O¯
0Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
08Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

If I choose non-participation at this first stage, I meet the wishof my opponent.

11

PayoffTable

I do not like to receive a payoff which is smaller than my opponent's.

The Reason for Your Decision on Participation
If my opponent chooses participation (O), it is most profitable for him toinvest 11 units.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
To avoid the case in which neither of us participates in investment (´´).

Your Payoff The Reason for Your Decision on Investment Number
4904

I always get a payoff which is higher than my opponent's.

PayoffTable

The Reason for Your Decision on Participation
The same as period 1.

Period 4 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 5 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
98Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
This would be a safe policy!?

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´ (where neither of us participates in investment).

Your Payoff The Reason for Your Decision on Investment Number
7250

Choosing this number would be profitable.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340
PayoffTable

The same as the above.
The Reason for Your Decision on Participation
This is a gamble.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´.

Your Payoff The Reason for Your Decision on Investment Number
2658

Choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
This is a gamble.

Your Payoff The Reason for Your Decision on Investment Number
4018

Your Payoff The Reason for Your Decision on Investment Number
8278

187

188

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 13 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
This is a gamble.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´.

Your Payoff The Reason for Your Decision on Investment Number
7340

Choosing this number is profitable.

PayoffTable

The Reason for Your Decision on Participation
This is a gamble.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´.

Your Payoff The Reason for Your Decision on Investment Number
2658

Choosing this number maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
To avoid the case ´´.

Your Payoff The Reason for Your Decision on Investment Number
6478

Choosing this number is profitable.

ID Number = 18, Male, Earnings = 2430 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I mainly used Payoff Tables 1, 2, and 3. Before the actual experiment started, I spend ten minutes to write data of the payoff
tables into Supplemental Payoff Tables 2. I never used Supplemental Tables 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
4. I participated in investment several times, but the number of periods at which I did not participate in investment
was greater than the number of periods at which I did.
The reasons for your decisions on participation:
When my opponent participated in investment, but I did not, my opponent almost always chose the number maximizing his
payoff and I also received a good payoff.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I expected that my opponent would choose 6-9. I chose around 7-8 to get a good payoff for such numbers.
When your opponent did not participate in investment:
I chose the number maximizing my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
The opponent's payoff should be also considered in selecting an investment number. If I behave selfishly, I might get a large
payoff, but might lose a lot. All of us become happy if everyone considers both his own payoff and his opponent's payoff
when making an investment decision (this is an ideal).

189

190

ID Number = 19, Male, Earnings = 2961 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

You
O
¯

Your
Opponent
´
¯

6

You
´
¯

You
O
¯

Your
OpponentO¯

The Reason for Your Decision on Participation
To avoid the case in which neither of us participates in investment andour payoffs are quite low (500).

Your Payoff The Reason for Your Decision on Investment Number
1007

By choosing this number, my payoff is not low and my
opponent's payoff is not large.

PayoffTable

The Reason for Your Decision on Participation
Choosing non-participation is profitable with probability 3/4.

Your Payoff The Reason for Your Decision on Investment Number

13

6117

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation
My payoff would be higher than at practice 2.

Your Payoff The Reason for Your Decision on Investment Number

7

6

3266

I am selfish and my payoff would be largest by investing this amount.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

102Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 3 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.

PayoffTable

I practice the same thing as at the previous period once more.
Your Payoff The Reason for Your Decision on Investment Number
2038

PayoffTable

I expected my opponent's investment number.

The Reason for Your Decision on Participation
I had a big bet at the first time.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I again tried non-participation because I got savings at period
1.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
The third of the payoff obtained at the previous period is compared withthe payoff obtained when both participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
706

191

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

611

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

68Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 9 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

PayoffTable

The Reason for Your Decision on Participation
I safely participated in investment this time.

Your Payoff The Reason for Your Decision on Investment Number
10384

Choosing this number would be safest, comparing with thecase in which both payoffs are 706.

PayoffTable

The Reason for Your Decision on Participation
This is a safe choice.

Your Payoff The Reason for Your Decision on Investment Number
7237

Choosing a middle number would be profitable as at period 4 of theactual experiment.

PayoffTable

The Reason for Your Decision on Participation
Because the number of my opponents who did not participate
in investment decreases.

Your Payoff The Reason for Your Decision on Investment Number
7340

I expected my opponent to choose 6, 7, or 8.

PayoffTable

The Reason for Your Decision on Participation

My opponent would choose non-participation (´) if
he is very greedy.
Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
If both participate in investment, I do not hurt my opponent, nor does myopponent.

Your Payoff The Reason for Your Decision on Investment Number2658

I narrowly escaped from receiving 706.

PayoffTable

The Reason for Your Decision on Participation
Because I was angry that my opponent did not participate in investment
at period 8.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I settled down now. I would like to avoid that my payoff is 706.

Your Payoff The Reason for Your Decision on Investment Number
6526

Choosing 8 is safest and it maximizes my payoff when my opponent's
number is between 6 and 8.

192

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

9

PayoffTable

The Reason for Your Decision on Participation
Participation is a safe strategy. Most people would have the badexperiences that their payoffs are 706.

Your Payoff The Reason for Your Decision on Investment Number
5766

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
Everyone seems to understand that participation is safe.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 19, Male, Earnings = 2961 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I took a look at Payoff Table 1. I found the number maximizing my payoff for each of my opponents' investment numbers. I
realized from a middle of the experiment that I could get the almost largest payoff by investing 8 units. After knowing a
knack about investment, I did not need to consider investment numbers carefully.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.

7345

The same as the above.

(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

PayoffTable

The Reason for Your Decision on Participation

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.

The same as the above.

The reasons for your decisions on participation:

Your Payoff The Reason for Your Decision on Investment Number
2386
PayoffTable

To punish the person who seeks only his own interest.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8225

The same as the above. Everyone looks like understanding
the situation.

At the first three periods, I went on the gamble that I did not participated in investment so as to get a large payoff. However
I realized that we could prevent a big loss when both of us safely participated in investment and invested 8 units, and so I
decided to participate in investment.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
8: My payoff is maximized by choosing 8 when my opponent invests 6-8 units.
When your opponent did not participate in investment:
11: My payoff is maximized by choosing 11.
8: The decrease of my payoff is relatively small, while the decrease of my opponent's payoff is relatively large.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
If everybody participate in investment and choose 8, none would suffer a large loss. I understood that taking selfish
behavior would lead to a serious problem. I am very happy to participate in the experiment.

193

194

ID Number = 20, Male, Earnings = 2346 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

12

9

4663

My opponent would also seek a reasonable payoff steadily.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

8

5

2942

Choosing this number would result in a reasonable payoff.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

10

10

5596

By choosing this number, my payoff would not be bad evenwhen my opponent's investment number is small.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

13

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 3 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
It would be safest to participate in investment and invest around 12 units.

Your Payoff The Reason for Your Decision on Investment Number

Participation would be profitable with high probability.
Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

My opponent would invest 13 units if I do notparticipate in investment, but my opponent does.
Your Payoff The Reason for Your Decision on Investment Number
6117

PayoffTable

The Reason for Your Decision on Participation
My opponent would participate in investment at the first time. If so, hewould invest 11 units.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
I do not understand why my opponent at period 1 invested 7 units. But I
tried non-participation once more.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Investment
6
7
NumberPeriod 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.
11
Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯

Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

6

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4018

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I do not understand why my opponents invested 7 units. I
tried participation this time.

Your Payoff The Reason for Your Decision on Investment Number
5766

My opponent would choose 7, 8, or 9.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

If my opponent participates in investment, but I do not, I can only
imagine that my opponent would invest 11 units. So I tried nonparticipation, expecting that my opponent would choose participation.
Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation

Perhaps most of my opponents at the previous periods did notunderstand the payoff tables. I did not participate in investment,
expecting that my opponent would invest 11 units.
Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

It cannot be helped.
The Reason for Your Decision on Participation
Hopefully my opponent would invest 11 units.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation
Why? My plan did not work well. I participated in investment to get areasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

195

196

Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
10
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

PayoffTable

The Reason for Your Decision on Participation
I had a bet once more. It is not meaningful to seek
the safety at this stage.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I do not understand why my opponent chose 0. I had a bet once more.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Not in particular.

Your Payoff The Reason for Your Decision on Investment Number
7031
PayoffTable

The Reason for Your Decision on Participation
Choosing 10 is mysterious. Anyway my strategy worked well and so I
tried non-participation again.

Your Payoff The Reason for Your Decision on Investment Number(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I almost always used Payoff Table 1 only.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
4. I participated in investment several times, but the number of periods at which I did not participate in investment
was greater than the number of periods at which I did.
The reasons for your decisions on participation:
As a matter of fact I planned to choose non-participation at all periods. However I changed my mind, because I could nothave things my own way many times.
(6) How did you choose your investment number when you participated in investment?

8278
PayoffTable

ID Number = 20, Male, Earnings = 2346 yen

The Reason for Your Decision on Participation
I decided no to participate in investment. If my opponent do notparticipate in investment, either, I will simply give up.

Your Payoff The Reason for Your Decision on Investment Number

When your opponent participated in investment:
Because my opponent always invested around 5-9 units, I continued to invest such units.
When your opponent did not participate in investment:
It did not occur.

8278(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
If you want to get a high payoff, do not participate in investment and let your opponent invest 11 units to earn 8278 perperiod (if you opponent do not participate in investment, give up). If you are satisfied with getting a normal payoff, itwould be best to invest 7-9 units continuously.

197

198

5. Data for the Tokyo Session B (with the "Opponent" Wording)
5.1. Pairs of Subjects (ID Numbers) in the Tokyo B Session: the Same as the Tsukuba A Session (see Table 3.1.).
5.2. Participation Decisions of Each Subject in the Tokyo B Session: 1 = Participate, O = Not Participate
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1

2

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

3

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

4

0
1
1
1
1
1
1
0
1
1
1
1
1
1
1

5

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

6

1
1
1
1
0
1
1
1
1
1
1
1
1
1
1

7

1
1
1
1
1
0
0
0
0
1
0
0
1
1
0

8

1
1
1
1
0
1
0
1
1
1
0
1
0
1
1

9

1
1
1
1
1
1
1
1
0
1
1
1
1
1
0

1
1
1
1
1
1
1
1
1
1
1
0
0
0
0

10 11 12 13 14 15 16 17 18 19 20
0
1
1
0
1
1
1
0
1
1
1
1
1
1
0
1
1
1
1
1
1
1
0
1
1
0
1
1
1
1
1
1
1
1
0
0
1
1
1
0
0
1
1
1
1
0
0
1
1
1
1
1
1
0
1
0
1
1
0
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
0
1
0
1
0
1
0
1
1
0
1
0
1
0
0
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1

5.3. Participation Decisions of Each Subject's Opponents in the Tokyo B Session: 1 = Participate, O = Not Participate
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1

2

1
1
0
1
1
1
1
1
1
1
1
1
1
1
1

3

0
1
1
1
0
1
1
0
1
1
1
1
1
1
0

4

1
1
1
1
1
0
1
1
1
0
1
1
1
1
1

5

1
1
1
1
1
1
1
0
1
1
1
0
1
1
1

6

1
1
1
1
1
1
1
1
1
1
1
0
1
1
1

7

1
1
1
1
0
0
1
0
1
1
1
1
1
0
1

8

1
1
0
1
1
1
1
1
1
1
1
1
1
0
1

9

1
1
1
0
0
1
1
0
1
1
1
0
1
1
1

0
1
1
0
1
1
1
1
0
1
1
1
1
1
1

10 11 12 13 14 15 16 17 18 19 20
1
1
1
1
0
1
1
1
0
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
1
0
0
1
1
1
1
0
1
1
0
1
1
0
1
1
0
1
0
1
0
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
0
0
1
0
1
1
1
1
1
1
1
1
1
0
0
1
1
0
1
0
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
1
0
0
1

199

5.4. Investment Numbers of Each Subject in the Tokyo B Session (blank means non-participation).
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1
13
9
11
9
8
8
8
7
8
6
8
8
10
8
8

2

3
2
7 9
7 6
7 8
2 6
7 11
7 7
2
7 6
7 11
7 8
7 8
6 8
6 8
2 8

4

7
7
7
9
7
7
7
1
7
7
7
0
7
7
7

5

6
5
6
5

5
6
5
6
5
6
11
5
6
5

6

7
7 7
7 5
6 11
8 8
11
8

8

10
7
7 8

9

7
7
8
8
8

8
8
11

7
7
7
6
6
7
7
6

1
4

6
9
4
6
4
9
8
8
6
8
8

10

11 12 13 14 15 16 17 18 19 20
6
8
4 6
4
0 7
6
7
7
6
10 7 11 6
0 6
6
7
9
3 7
4 8
0 8
6
8
11
4 5
3 8
6
9
11 10 6
6 6
2
11
8
9
12 7
7 6
2 8
6
9
9
6
4 8
7 0
0 8
6
9
6
9
1
0
6
11
0 7
3 6
3 8
6
0 10
7 10 8
7 6
3 8
6
0 10
7
0 8
7 6
3 10 11
3
4
4 6
7 6
3 8
6
11
6
0 7
2 6
2 8
6
11
9
8 7
7 8
8 8
6
9
8
7
6 9
7 8 11 8
65.5. Investment numbers of Each Subject's Opponents in the Tokyo B Session (blank means non-participation).
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1

2
7
5

8
6
7
9
8
11
6
7
3
6
8
7

3
6
7 5
0 8
9 9
9
12
7 7
9
6 8
7
6 7
6 4
10 6
8 7
5

4

5
7
7
4
7
4
9
6

3
10
8

7
9
7
6
6
8
8
6
6
0
7

8
7
8

2
8
8

6
7
13 6
7 9
3
8 3
11
9
0 0
9
3 7
8 7
11 10
4 3
6 2
2

6

8

9
7
7
9

8
7
0
8
3
7
9
8

10 11 12 13 14 15 16 17 18 19 20
2
6
7
0
4
6 4
8
6
6 6
0
6 11
7 10
6
7 7
9
7 11
4
7 11
6 6
7 6
7 6
8
5
4 11
8
6 6
8 8
5
7 6
2 11
2 6
8 6 10 11
8
5
7 11
7 6
8 2
6 7
7
8 4
6
8
9
8
7
6
7
7 6 10
5
1
2 6
0
1
8
6
7
6
7 6
7
7 5
7 11
7
6 8
3 6
7 8 10
6 7
8
0
8
10
0 8
7
8 8
11
0
8 7
6 8
8 6
7
0
6 11
8
8
5 7
8
11
8
1 11
6 7
8 6
6 8
8
11 8
7
9
6
7
8 9
4

200

5.6. Pairs of Investment Numbers in the Tokyo B Session (blank means non-participation and boldfaced numbers indicate data of subjects
who did spiteful behavior).
Period 1
ID # Invest. #1,6 13
7
2,10
2
3,9
6
4,8
7
7
5,7
6
7
11,20
6
6
12,19
8
7
13,18
0
14,17
4
15,16
6
4

Period 2
Period 3
Period 4
Period 5
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #1,5
9
5
1,10 111,3
9
8 1,16
8
6
2,8
7
7
2,18
7
0
2,4
7
9 2,11
2
3,7
9
5
3,17
6
8 5,205
6 3,10
6
9
4,6
7
7
4,16
7
4 6,19
8
8
4,9
7
4
9,20
9
6
5,15
6
7 7,18
8
3
5,8
6
10,19
7
6
6,14
6
3 8,176
6,7 1111,18
7
07,13 11
9,16
6
12,20
11
12,17
6
6
8,12
7
9 10,158
5 13,19 11
13,16
11
9,11
4
7 11,14
4 14,18 102
14,15 10
7 19,208
6 12,13
11 15,17
6
6

Period 9
ID # Invest. #
1,11
8
11
2,20
7
6
3,19
6
8
4,18
7
3
5,17
6
6
6,16
3
7,15
7
7
8,14
0
9,13
6
10,12

Period 10
ID # Invest. #
1,17
6
6
2,13
7
7
3,12 11
4,11
7 10
5,10
5
0
6,9
7
8
7,8
8
7
14,20 10
6
15,19
8
8
16,18
7
3

Period 6
Period 7
Period 8
ID # Invest. # ID # Invest. # ID # Invest. #1,8
8
7 1,12
8
9
1,9
7
8
2,14
7 12
2,3
7
7 2,162
3,13 114,20
7
6 3,15
94,12
7
9 5,196
8 4,14
1
5,11
5
8 6,18
0 5,13
5
6
6,10
7,17
0 6,12
7,98
9 8,167
7 7,11 10915,20
7
6 9,158
8 8,10
6
16,19
7
8 10,14
4 17,201
6
17,18
6
2 11,139
6 18,190Period 11
Period 12
Period 13
Period 14
Period 15
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #1,13
8
7 1,188
3
1,2 10
6 1,19
8
8
1,4
8
7
2,5
7
6 2,157
6 3,208
6 2,17
6
8
2,6
2
3,4
8
7 3,148
4 4,197
8 3,16
8
7
3,5
8
5
6,20
11 4,135,18
5
2 4,157
7 7,204
6
07,19
10 5,12 116,17
8
6 5,14
6
8 8,198
8,18
7
3 6,11
4 7,162 6,13 11
9,18
11
9,17
8
6 7,108
3 8,158
7 7,12
10,17
9
8
1
10,16
0
7
8,9
8
9,14
0 8,118
9 11,168
7
11,15 10
8 16,207
6 10,13 11
9,10
11 12,15
912,14
6
8 11,1218,20
8
6 13,147
6
0 17,196

201

5.7. Payoffs of Each Subject in the Tokyo B Session
ID #1
2
Period 1 5406 1072
Period 2 5101 6478
Period 3 2658 2210
Period 4 7250 8271
Period 5 5766 1072
Period 6 6526 11480
Period 7 8225 6478
Period 8 7340 1072
Period 9 10173 5681
Period 10 5515 6478
Period 11 6526 5681
Period 12 3831 5681
Period 13 5677 9257
Period 14 7345 7237
Period 15 6526 1072

3
3244
5101
7237
8225
8209
2658
6478
5907
7237
2658
6526
4420
5766
6526
5064

4
6478
6478
4281
6481
4281
8271
5681
871
3675
9270
7340
706
7340
6478
7340

5
6
6339 12694
8043 6478
6339 3463
5272 7345
3244 2658
7038
706
7237
706
5272
706
5515 1554
1775 7340
6339 8278
2658 2017
2658 5766
7237 2658
7038 1186

7
5681
8043
2658
3831
8278
8225
706
7816
6478
6526
7031
3831
1186
871
4960

8
6478
6478
8271
2003
2003
7340
6478
2003
706
7340
3675
2386
6526
8225
4904

9
2003
5765
5812
2003
5812
7250
7345
6526
2003
6526
5766
4904
706
8278
8278

10
1186
5681
8278
5064
5765
706
2017
3244
706
2578
4018
6383
2658
2658
7250

11
5515
2210
4281
2017
1186
5064
5765
8951
6765
6343
7056
1536
2003
7250
6526

202

12
6526
5515
6481
8278
8278
6481
7250
706
706
8278
706
8278
3244
905
5907

13
706
8278
8278
2658
2658
8278
8209
4762
3244
6478
7340
706
8278
8278
5681

14
1536
6343
4590
1536
3465
5800
1536
905
706
5677
706
6751
706
5766
6339

15
4078
9270
5681
7038
5515
5681
7345
2523
6478
7345
9168
6339
7340
6478
2523

16
4960
2658
5812
3244
7237
7340
6478
1186
1297
3675
2210
5681
1072
7340
7340

17
2017
5515
5766
3244
5515
2913
706
3718
5515
5515
7237
7237
7237
5766
8225

18
706
4018
4018
6383
8130
4171
706
706
5440
5440
5440
6383
3432
5766
2658

19
7340
6339
5766
7345
8278
6526
5766
706
5766
7345
2615
5766
6526
7345
2386

20
5515
8209
7237
4762
2658
6339
6339
2427
6339
9257
2658
6339
7237
7237
4078

4.8. Record Sheets and Questionnaires for Tokyo Session B
ID Number = 1, Male, Earnings = 3,098 yen
Practice 1

Participation
in investment
Invest. Num.

Practice 2

Participation
in investment

Invest. Num.
Practice 3

Participation
in investment

Invest. Num.
Practice 4

You
O
¯

Your
Opponent
O
¯

9

7

You
´
¯

You
O
¯

Your
OpponentO¯

PayoffTable

Invest. Num.

1210Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
7

Anyway I will invest all units at four practice periods and divide 24 units
at the remaining three periods. I chose 9 units rather than 8 units because
my payoff would be larger (perhaps my opponent would choose 8).
The Reason for Your Decision on Participation

Investment numbers might be constant although payoffs are large.
However, all people would choose participation at four practice periods.
So I chose non-participation this time to play the game with them till thelast.
Your Payoff The Reason for Your Decision on Investment Number

Payoff
Table

O
¯

13

3980

Your
Opponent´¯

Participation
in investment

Invest. Num.

Your Payoff The Reason for Your Decision on Investment Number

6117

Your
OpponentO¯

The Reason for Your Decision on Participation
Everyone would choose participation to look at what would happen at
the beginning of the game. I would like to make the game exciting.

13

3

You

PayoffTable

The Reason for Your Decision on Participation

If all people, including me, use all units of money at four practice periods,
then all people would select participation at practice 1 and practice 4, andchoose either participation or non-participation at practice 2 and 3. I
think this is an interesting (and enjoyable) way to play the game.
Your Payoff The Reason for Your Decision on Investment Number
637

I do not intend to make the market flat, but I wish to spend a lot of moneyat the last time. I can invest 3 units only today.

PayoffTable

The Reason for Your Decision on Participation
Because this is the last time.

Your Payoff The Reason for Your Decision on Investment Number
5143

Payoff
Table

Wait a minute. I have misunderstood the rule of the game. 24 units ateach period? I blew it.

The Reason for Your Decision on Participation
I carefully read the rule of the game this time. I expected that everyone
would participate in investment, and so I do the same thing.

Your Payoff The Reason for Your Decision on Investment Number
5406

My management policy is "both I and you get high payoffs". I will always
choose 13.

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

5

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯
Invest. Num.

11

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

98Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
89Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

203

9

7

8

PayoffTable

The Reason for Your Decision on Participation
Participation is a safe policy.

Your Payoff The Reason for Your Decision on Investment Number
5101

Choosing 9 is one of the most profitable numbers if my opponent invests
7 units.

PayoffTable

The Reason for Your Decision on Participation
Anyway "participation". I should not choose non-participation until I win
the confidence.

Your Payoff The Reason for Your Decision on Investment Number
2658

11 is the number which maximizes my payoff. My opponent gets 10,000
points. There is no problem.

PayoffTable

The Reason for Your Decision on Participation
I cannot imagine non-participation. Participation serves for the publicbenefit.

Your Payoff The Reason for Your Decision on Investment Number
7250

I hope that larger investment numbers will be traded in the market. 9 is
the most profitable number when my opponent invests 5.

PayoffTable

The Reason for Your Decision on Participation
The game is becoming interesting. My average payoff is about 5,000
points.

Your Payoff The Reason for Your Decision on Investment Number
5766

8 is the most profitable number when my opponent invests 8.

PayoffTable

The Reason for Your Decision on Participation
I can get 5,000 points surely (by participation), and so I do not choose
participation.

Your Payoff The Reason for Your Decision on Investment Number
6526

8 is the most profitable number when my opponent invests 6.

PayoffTable

The Reason for Your Decision on Participation
Participation will be profitable definitely.

Your Payoff The Reason for Your Decision on Investment Number
8225

8 is the most profitable number when my opponent invests 7.

PayoffTable

The Reason for Your Decision on Participation
I participated in investment, but can I get a large payoff next time?

Your Payoff The Reason for Your Decision on Investment Number
7340

7 is the most profitable number when my opponent invests 9.

204Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment

PayoffTable

The Reason for Your Decision on Participation
Again I will get a large payoff (by participation).

Your Payoff The Reason for Your Decision on Investment Number
Invest. Num.
811Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
66
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.
87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
83
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
10
6Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

10173

8 is the most profitable number when my opponent invests 8.

PayoffTable

The Reason for Your Decision on Participation
Is the current situation a boom?

Your Payoff The Reason for Your Decision on Investment Number
5515

6 is the most profitable number when my opponent invests 11.

PayoffTable

The Reason for Your Decision on Participation

I participated in investment, but I feel that the bubble burst suddenly. If
the same situation happens at next period, I might choose nonparticipation.
Your Payoff The Reason for Your Decision on Investment Number
6526

8 is the most profitable number when my opponent invests 6.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at period 7 of the actual experiment.

ID Number = 1, Male, Earnings = 3,098 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 1) in Actual Experiment(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
I used the red table most often. I know that I get 30,000 points if I do not participate in investment and my opponent
invests 24, but this would never happen. Because there is no data except the payoff tables, everyone would have thesame answers. So the key to win this game would be to get reasonable payoffs safely by investing 8 units. A precept:
respect the market.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
1. I always participated in investment.
The reasons for your decisions on participation:

3831

8 is the most profitable number when my opponent invests 8.

Non-participation is an action that requires my opponent to trust me. Because I receive a high payoff if my opponent
invests 24, even though I do not participate in investment. However, such an action is meaningless when everyone faces
the same condition.

PayoffTable

The Reason for Your Decision on Participation(6) How did you choose your investment number when you participated in investment?

I have never considered non-participation.

When your opponent participated in investment:

Your Payoff The Reason for Your Decision on Investment NumberYour Payoff The Reason for Your Decision on Investment Number
5677

10 is the most profitable number when my opponent invests 3.

PayoffTable

The Reason for Your Decision on Participation
I intend to participate in investment till the last period.

Your Payoff The Reason for Your Decision on Investment Number
7345

8 is the most profitable number when my opponent invests 6.

PayoffTable

The Reason for Your Decision on Participation
I can choose non-participation, but the market is still inactive.

I chose the number maximizing my payoff if my opponent chose the investment number that was estimated based on
the data of my opponents' investment numbers at the previous periods.
When your opponent did not participate in investment:
I chose the number maximizing my payoff, and did not care about my opponent's payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
Participate in investment at all periods. By choosing participation we can receive 5,000 points of payoff. Get reasonablepayoffs safely. Do not try to get a large payoff. Learn that you always experience a counteraction after getting a large
payoff. Do not try to move the market. Follow the market trend. Even when you lose, let the opponent receive a highpayoff. Minimize your loss and recover the loss in the long run. Do not pursue the desired number. Decide aninvestment number based on your current situation.

Your Payoff The Reason for Your Decision on Investment Number
6526

8 is the most profitable number when my opponent invests 8.

205

206

ID Number = 2, Male, Earnings = 2,614 yen.
Practice 1

Participation
in investment
Invest. Num.

Practice 2

You
O
¯

Your
Opponent
O
¯

9

6

3491

My opponent would not choose 14 or more because his payoff is small.
By investing 7-9, I could get a reasonable payoff on average if my
opponent chooses 13 or less.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investmentO¯

Invest. Num.

4

Practice 3

You

Participation
in investmentO¯

Invest. Num.
Practice 4

4
You

Your
Opponent´¯

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

93

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

2

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
Because participation is surely positive.

Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
743

Because my opponent did not participate in investment, I attempted torestrain my opponent from receiving a large payoff and make my payoff
not small.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number743

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
1195

PayoffTable

The same as the reason specified at practice 1.

The Reason for Your Decision on Participation
Because participation is surely positive.

Your Payoff The Reason for Your Decision on Investment Number
1072

Because my opponent did not participate in investment, I attempted torestrain my opponent from getting a large payoff and make my payoff
not small.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number
6478

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
‚O
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
79Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
2Invest. Num.
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
12Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
2Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

6

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number
2210

The same as the reason specified at Period 2.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number
8271

The same as the reason specified at Period 2.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number1072

The same as the reason specified at Period 1.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number
11480

The same as the reason specified at Period 2.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the reason specified at Period 2.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number1072

The same as the reason specified at Period 1.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the reason specified at Period 2.

My opponent would not choose 14 or more because his payoff is small.
However he might select a little smaller number to beat me next time.
Thus I chose this number.

207

208

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

10Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

2

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number
6478

The same as the reason specified at Period 2.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the reason specified at Period 2.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the reason specified at Period 2.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 2, Male, Earnings = 2,614 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
I mainly used Supplement Payoff Tables 1 and 2. I understood well that by simply investing many units, I could not geta high payoff at all.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
1. I always participated in investment.
The reasons for your decisions on participation:
Because I can always receive benefit from participating in investment.
(6) How did you choose your investment number when you participated in investment?

9257

From the past experiences, I think that choosing 6 is better than choosing
7 when comparing my opponent's payoff with my payoff.

PayoffTable

The Reason for Your Decision on Participation

Supposing that my opponent has the same idea, I chose a number in an attempt to make my payoff as high as possible
and not to give my opponent great benefit.

The same as the reason specified at Period 1.

When your opponent did not participate in investment:

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the reason specified at Period 13.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason specified at Period 1.

When your opponent participated in investment:

Because investing nothing does not pay, I chose a number in order to restrain my opponent from getting great payoffand make my payoff as high as possible.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
Participate in investment at all periods. A good way to choose investment numbers would be the one I took at thisexperiment.

Your Payoff The Reason for Your Decision on Investment Number1072

The same as the reason specified at Period 1.

209

210

ID Number = 3, Female, Earnings = 2,813 yen
Practice 1

Participation
in investment
Invest. Num.

Practice 2

Participation
in investment

Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You
O
¯

Your
Opponent
O
¯

10

4

You
O
¯

8

You
O
¯

Your
Opponent
O
¯

6

Your
Opponent
´
¯

13
You
´
¯

Invest. Num.

Your
OpponentO¯
13

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

95

PayoffTable

The Reason for Your Decision on Participation
Because I can understand the situation better by participating ininvestment than by non-participating defensively.

Your Payoff The Reason for Your Decision on Investment Number
2708

PayoffTable

I expected my opponent's investment number to be around 10. If so, thenthe difference of the possible payoffs that I might receive would be small
when I invest 10.
The Reason for Your Decision on Participation

I somehow thought that nobody would participate in investment. My
payoff would be low if I do not participate in investment, either. Thus I
decided to choose participation
Your Payoff The Reason for Your Decision on Investment Number
3405

Payoff
Table

Because I invest a little too much at the first round.
opponent would invest large units.

I felt that my

The Reason for Your Decision on Participation
Everyone seems to be rather conservative (always choose participation).
My payoff would be low if I did not choose participation.

Your Payoff The Reason for Your Decision on Investment Number
1631

Because it is clear that my payoff is highest if I invest 13.

PayoffTable

The Reason for Your Decision on Participation
Because I want to try non-participation to look at what would happen.

Your Payoff The Reason for Your Decision on Investment Number
6117

PayoffTable

The Reason for Your Decision on Participation
I would like to get benefit surely because everyone would participate ininvestment at the first time.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation
Because of my failure by choosing non-participation at period 1.

Your Payoff The Reason for Your Decision on Investment Number
5101

I felt my opponent would invest large units because his or her way tocircle "Participation" in the participation card was brave.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

89Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
69Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
9
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

211

6

6

8

PayoffTable

The Reason for Your Decision on Participation
I feel participation more fun.

Your Payoff The Reason for Your Decision on Investment Number
7237

I was not certain which number should be selected, and I chose 6
somehow.

PayoffTable

The Reason for Your Decision on Participation
Because I do not like that my payoff is 706 if both my opponent and I do
not participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
8225

My opponent's way to circle "Participation" in the participation card wasbrave. I feel that choosing 8 would be safe.

PayoffTable

The Reason for Your Decision on Participation
Because participation is more exciting.

Your Payoff The Reason for Your Decision on Investment Number
8209

My opponent would be conservative.

PayoffTable

The Reason for Your Decision on Participation
I get the hang of this game.

Your Payoff The Reason for Your Decision on Investment Number
2658

I thought I got the hang of it, but my opponent was a chicken. It is finethat I can get the highest payoff.

PayoffTable

The Reason for Your Decision on Participation
I wish to be a challenger one more time.

Your Payoff The Reason for Your Decision on Investment Number
6478

I felt from his or her handwriting that my opponent would make thedecision quickly and would be an active person, so that he or she would
choose a relatively large number.

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to try non-participation once in a while.

Your Payoff The Reason for Your Decision on Investment Number
5907
PayoffTable

The Reason for Your Decision on Participation
I have never got a pleasant experience by selecting non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7237

I decide to choose 6 when I am not certain what to do.

212Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

87Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

84Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

5

PayoffTable

The Reason for Your Decision on Participation
Because I finally establish my theory.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 3, Female, Earnings = 2,813 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.

2658

I do no care.

PayoffTable

The Reason for Your Decision on Participation(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?

I would like to prove my theory this time.

I almost always looked only at the pink payoff tables 1, and I seldom used supplemental payoff tables 1-1 and 1-2.

Your Payoff The Reason for Your Decision on Investment Number
6526

Payoff
Table

Because the other person would establish his or her theory, I expected
him or her to invest 6-8.
The Reason for Your Decision on Participation
I get angry if my opponent does not participate in investment, and so I
choose participation.

Your Payoff The Reason for Your Decision on Investment Number
4420

I decide to choose 8 from now on. Choosing 8 or 6 seems to avoid afailure. Why?

PayoffTable

The Reason for Your Decision on Participation
I have no more reason to write down.

Your Payoff The Reason for Your Decision on Investment Number(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
First I thought that if I did not participate in investment, then my opponent would choose the most advantageous
investment number which maximizes his or her own payoff. However, everyone spited me and did not care about his or
her small loss. Therefore I realized that participation was better.
(6) How did you choose your investment number when you participated in investment?

5766

Choosing 8 is best. Because everyone would realize it and my opponent
would choose 6-8.

PayoffTable

The Reason for Your Decision on Participation

I realized at later periods that everyone would invest 6-8 generally. If so, then investing 8 would be most advantageousand I fixed my investment number at 8.

I understand from my experiences that I should choose participation.

When your opponent did not participate in investment:

Your Payoff The Reason for Your Decision on Investment Number
6526

I have already decided to choose 8.

PayoffTable

The Reason for Your Decision on Participation
Choosing non-participation at the last time is stupid.

When your opponent participated in investment:

I chose the most advantageous investment number that maximizes my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
I think that my opponent would have the almost same idea as mine. Thus my opponent would invest 5 if I invest 5.
Accordingly, it would be good to choose the same investment number such that the payoff is maximized. However, it
might be better to choose a number which is slightly smaller than that number, taking account of risk.

Your Payoff The Reason for Your Decision on Investment Number
5064

Investing 8 is good after all.

213

214

ID Number = 4, Female, Earnings = 2804 yen
Practice 1

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

98Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You

You
O
¯

Your
Opponent
´
¯

1

You

The Reason for Your Decision on Participation

If I chose non-participation and my opponent selected participation, thenhe or she would think that "I get a small payoff, but the other person can
get a large payoff." (It is possible that both may fall together.)Your Payoff The Reason for Your Decision on Investment Number
4512

PayoffTable

I chose a number so that I could receive a large payoff if my opponent's
investment number is smaller than it, and I could get a reasonable payoff
even if his or her investment number is larger than it.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
513

Because I feel bitter. (You should choose participation and invest 0 rather
than non-participation.)

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

8

9

5080

The same as the one specified at practice 1.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation´¯

Invest. Num.

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

I would like to try non-participation once during practice periods.
Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

PayoffTable

7

7

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
4
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

97

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
4
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
79Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment
¯
¯

6478

The same as the reason specified at practice periods.

Invest. Num.
7
6
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

PayoffTable

The Reason for Your Decision on Participation

Invest. Num.

The same as the above.

Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

PayoffTable

The Reason for Your Decision on Participation
I realized that my payoff would not be large if I did not participate ininvestment (the same as the one specified at practice periods).

Your Payoff The Reason for Your Decision on Investment NumberYour Payoff The Reason for Your Decision on Investment Number
6478

The same as the above.

Invest. Num.

215

1

7

3

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4281

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6481

I increased my investment number to cope with the person who facedwith me at period 3 of the actual experiment.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4281

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8271

The same as the above. (Why did my opponent at period 5 choose 4?)

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
871

Because I feel bitter. This is the second time. My payoff is too small,comparing with my opponent's payoff. (However I did not choose 0.)

PayoffTable

The Reason for Your Decision on Participation
The same as the one specified at practice 1.

Your Payoff The Reason for Your Decision on Investment Number
3675

The same as the one specified at practice 1.

216Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
10Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

0

Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

8

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
9270

The same as the above. (Why did he or she choose 3?)

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

Because I feel bitter. This is the third time. I do not like to choose 0
because it seems to be the same as non-participation, but....

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 4, Female, Earnings = 2804 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
By looking at supplemental tables 1-2 (in which I drew lines), I searched for the most profitable investment numbers forthe numbers that my opponent would choose. (I expected my opponent to choose 6-12.)(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
4. If I can make my opponent's payoff as small as possible, it is fine that my payoff is moderate.
However I like to have a larger payoff than my opponent does.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
1. I always participated in investment.
The reasons for your decisions on participation:
Because my payoff would not be large by choosing non-participation. When I select 0, the other person maximizes his or
her payoff by investing 11. Then my payoff is 8278 that is not so large although there is high risk.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
7-8 because of the reason specified in (3). I chose 7 at all periods except one at which I invested 9 (but I failed and thenwent back to 7).
When your opponent did not participate in investment:

6478

The same as the above.

0-1 because I felt bitter.

PayoffTable

The Reason for Your Decision on Participation(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?

The same as the above.

I did not get it. So I could not change the number that I thought to be best.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

217

218

ID Number = 5, Female, Earnings = 2706 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You
O
¯

Your
Opponent
O
¯

12

8

4213

Because my payoff is largest when my opponent's investment number issmallest (that is, 1).

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

8

7

3915

By looking at the supplemental tables 1-2.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
0
You
´
¯

Your
Opponent´¯

Invest. Num.

67

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation
Because by choosing participation, my payoff may become large even if
my opponent does not participate in investment.

Your Payoff The Reason for Your Decision on Investment Number

Because of a little failure at the first period.
Your Payoff The Reason for Your Decision on Investment Number

To maximize my profit.
Your Payoff The Reason for Your Decision on Investment Number
500

Because my opponent gains if I choose a number larger than 0.

PayoffTable

The Reason for Your Decision on Participation
Because I have participated in investment past three times.

Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

PayoffTable

5

9

PayoffTable

The Reason for Your Decision on Participation
Because I think that I get more benefit by participation than by nonparticipation.

Your Payoff The Reason for Your Decision on Investment Number
6339

Because my payoff increases largely as my opponent's investment
number increases.

PayoffTable

The Reason for Your Decision on Participation
Because I would like to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
8043

The same as the one specified at period 1.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

5

6

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
58Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
5
6
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

219

6

6

6

PayoffTable

The Reason for Your Decision on Participation
Because it is easier to maximize my profit by participation than by nonparticipation.

Your Payoff The Reason for Your Decision on Investment Number
6339

Because my opponent would invest so that his payoff is as high as
possible when I invest 1.

PayoffTable

The Reason for Your Decision on Participation
Because participation would be more beneficial.

Your Payoff The Reason for Your Decision on Investment Number
5272

Because as the distance between two iso-payoff curves is smaller, thepayoff is larger.

PayoffTable

The Reason for Your Decision on Participation
Because I would like to know what happens when I choose nonparticipation.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation
Because participation would be more beneficial.

Your Payoff The Reason for Your Decision on Investment Number
7038

Because I expected my opponent to invest 7-9.

PayoffTable

The Reason for Your Decision on Participation
Because I would like to invest something.

Your Payoff The Reason for Your Decision on Investment Number
7237

Because I expected my opponent to invest 7-9.

PayoffTable

The Reason for Your Decision on Participation
Because investment would be more beneficial.

Your Payoff The Reason for Your Decision on Investment Number
5272

Because I expected my opponent to invest 7-9.

PayoffTable

The Reason for Your Decision on Participation
Because participation would be more beneficial.

Your Payoff The Reason for Your Decision on Investment Number
5515

Because I expected my opponent to invest 6-9.

220Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
50Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
52
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

5

8

PayoffTable

The Reason for Your Decision on Participation
To maximize my profit.

Your Payoff The Reason for Your Decision on Investment Number
1775

Because I expected my opponent to invest 6-9.

PayoffTable

The Reason for Your Decision on Participation
To maximize my profit.

Your Payoff The Reason for Your Decision on Investment Number
6339

Because I expected my opponent to invest 6-9.

PayoffTable

The Reason for Your Decision on Participation
To maximize my profit.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff become largest (by choosing this number).

PayoffTable

The Reason for Your Decision on Participation
To maximize my profit.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 5, Female, Earnings = 2706 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
1) I wondered whether these payoff tables are made according to some rule.
2) I looked at payoff table 1 and supplemental payoff table 1-2.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
4. If I can make my opponent's payoff as small as possible, it is fine that my payoff is moderate.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
I did not participate in investment only one time, because I wanted to know what would happen if I did not participate
in investment.

2658

Because I expected my opponent to invest 6-9.

(6) How did you choose your investment number when you participated in investment?

PayoffTable

The Reason for Your Decision on Participation

When your opponent participated in investment:

To maximize my profit.

I chose an investment number such that the distance between two iso-payoff curves is as narrow as possible.

Your Payoff The Reason for Your Decision on Investment Number

When your opponent did not participate in investment:

7237

Because I expected my opponent to invest 6-9.

I chose the number maximizing my payoff.

PayoffTable

The Reason for Your Decision on Participation(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?

To maximize my profit.
Your Payoff The Reason for Your Decision on Investment Number
7038

Because I expected my opponent to invest 6-9.

221

I thought it would be best to choose a number such that the distance between two iso-payoff curves is narrow (that is,
the rate of increase in my payoff is large when my opponent' investment number increases by 1) if both participate ininvestment.

222

ID Number = 6, Female, Earnings = 2,097yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

8

12

7206

Because I expected my opponent's investment number to be around 10.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on ParticipationO¯

Because I wanted to try both participation and non-participation inpractice.
Your Payoff The Reason for Your Decision on Investment Number

Because practice 1 went well by choosing participation.
Your Payoff The Reason for Your Decision on Investment Number

5

2602

Because I would not suffer a large loss for any investment number of my
opponent.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You
O
¯

7

Your Payoff The Reason for Your Decision on Investment Number
1416

Your
Opponent´¯

Payoff
Table

13

7

Because I wanted to try both participation and non-participation.

6

13

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation

6

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

PayoffTable

7

The Reason for Your Decision on Participation
Because I would like to get a benefit.

Your Payoff The Reason for Your Decision on Investment Number
1631

Because I can receive the highest payoff.

PayoffTable

The Reason for Your Decision on Participation
Because I expected my opponent to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
12694

Because I expected my opponent would choose a number between 5 and8.

PayoffTable

The Reason for Your Decision on Participation
Because the first period went well.

Your Payoff The Reason for Your Decision on Investment Number
6478

Because I expected my opponent would also choose a number between 5
and 8.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

3

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 6 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

223

6

3

PayoffTable

The Reason for Your Decision on Participation
Because participation would be more beneficial than non-participation.

Your Payoff The Reason for Your Decision on Investment Number
3463

Because I expected my opponent would also choose a number between 5
and 8.

PayoffTable

The Reason for Your Decision on Participation
Because the last time did not go well.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because choosing this number seems to be profitable.

PayoffTable

The Reason for Your Decision on Participation
Because I felt participation would go well.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff is maximized.

PayoffTable

The Reason for Your Decision on Participation
Because I expected I could get a gain by making the decision opposite tothe one last time.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation this time.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation.

Your Payoff The Reason for Your Decision on Investment Number
1554

224

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
Your
Opponent
Participation
XO
in investment¯¯
Invest. Num.

2

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to get a benefit.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because choosing this number seems to result in no big failure.

PayoffTable

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation.

Your Payoff The Reason for Your Decision on Investment Number
2017
PayoffTable

The Reason for Your Decision on Participation
Because I have suffered a loss (by non-participation).

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 6, Female, Earnings = 2,097yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
By comparing table 2 with table 3, I found that my opponent gets the largest payoff by investing 11 when I do notparticipate in investment.
I found by table 1 that if I invest 5-7, then my opponent would invest similar units.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:

5766

Because this is safe.

I expected my opponent to invest 11 when I did not participate in investment. However, my opponents did not choosethat number.

PayoffTable

The Reason for Your Decision on Participation(6) How did you choose your investment number when you participated in investment?

Because I would not suffer a loss.

When your opponent participated in investment:

Your Payoff The Reason for Your Decision on Investment Number

I chose safe numbers (5-7).

2658

Because my payoff is largest.

When your opponent did not participate in investment:

PayoffTable

The Reason for Your Decision on Participation

I chose the number that maximizes my payoff.

Because I expected my opponent to choose participation.

(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
1186

225

Because the experiment repeats no less than 15 times and my opponent changes every period, it does not make sense tocare about my own payoff and my opponent's payoff every period. However, several persons cared about them.
Therefore it is better to invest some units rather than choose non-participation and expect my opponent to invest large
units.

226

ID Number = 7, Male, Earnings = 2512 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

8

9

5080

Because I expected that my opponent would not invest a large number
nor a small number to look at what would happen.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

12

9

4663

Because I expected my opponent to invest small units.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You
O
¯
3

I wish to get a large payoff.
Your Payoff The Reason for Your Decision on Investment Number

I wanted to try non-participation to look at what would happen.
Your Payoff The Reason for Your Decision on Investment Number

Your
OpponentO¯

PayoffTable

Invest. Num.
7
6
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
5Your Payoff The Reason for Your Decision on Investment Number

680

9

9

The Reason for Your Decision on Participation
I would like to look at what would happen for the time being.

3

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
My payoff was low last time. I would like to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number4039

I expected my opponent to invest large units.

PayoffTable

The Reason for Your Decision on Participation
I wished to receive a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
5681

I expected my opponent to invest small units.

PayoffTable

The Reason for Your Decision on Participation
Because my expectation came true last time.

Your Payoff The Reason for Your Decision on Investment Number
8043

I expected my opponent to invest 10-15.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
83
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
89Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

0

Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

109Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

227

7

7

PayoffTable

The Reason for Your Decision on Participation
I wish to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my opponent did not participate in investment, I chose a numberthat maximizes my payoff.

PayoffTable

The Reason for Your Decision on Participation
I wish to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
3831

I expected my opponent to invest 6-8.

PayoffTable

The Reason for Your Decision on Participation
Because my opponent's investment was not large, I tried to get a payoff
surely.

Your Payoff The Reason for Your Decision on Investment Number
8278

I expected my opponent to invest 11 certainly (his payoff is highest in thetable O´).

PayoffTable

The Reason for Your Decision on Participation
I wish to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
8225

I expected my opponent to invest 6-8.

PayoffTable

The Reason for Your Decision on Participation
I tried to get a payoff surely.

Your Payoff The Reason for Your Decision on Investment Number
706

Because my opponent will choose 11 certainly and I wish to get a highpayoff.

PayoffTable

The Reason for Your Decision on Participation
Because my expectation went wrong last time.

Your Payoff The Reason for Your Decision on Investment Number
7816

I expected my opponent to choose 10-14. I get around 7000 points even if
he or she chooses 17-19.

PayoffTable

The Reason for Your Decision on Participation
I would like to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
6478

I expected my opponent to choose 7-9.

228Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
10
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
83
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
2
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

1

Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

4

6

PayoffTable

The Reason for Your Decision on Participation
I would like to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 7, Male, Earnings = 2512 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.

6526

I expected my opponent to choose 7-9.

PayoffTable

The Reason for Your Decision on Participation(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?

Because my opponent's investment number was not large.

I took a look at the payoff tables 1 mainly.

Your Payoff The Reason for Your Decision on Investment Number
7031

My opponent would choose 11 if he or she wants to get a higher payoff.

PayoffTable

The Reason for Your Decision on Participation
I wished to get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
3831

I expected my opponent to choose 7-9.

PayoffTable

The Reason for Your Decision on Participation
I would get a payoff surely (provided that my opponent tries to get ahigher payoff).

Your Payoff The Reason for Your Decision on Investment Number(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
4. If I can make my opponent's payoff as small as possible, it is fine that my payoff is moderate.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
When I do not participate in investment, but my opponent does, if he wants to make his payoff high, then he would
choose 11. If this is true, I could get 8278 surely. However, my opponents had the same idea and often wrote small
numbers. After all, my payoffs were low.

1186

I could get 7000-8000 if my opponent chooses 11.

(6) How did you choose your investment number when you participated in investment?

PayoffTable

The Reason for Your Decision on Participation

When your opponent participated in investment:

My payoffs were small and so I try my luck.

I wrote how my opponents invested in another sheet. Choosing 9, 7, or 10 was frequently observed. I chose 8-10 tomaximize my payoffs for such investment numbers (choosing 9 was observed six times and choosing 7 was observed
two times, including practice periods).

Your Payoff The Reason for Your Decision on Investment Number871

I chose a number so that the difference between my payoff and my
opponent's is small. I did not like to choose 0.

PayoffTable

The Reason for Your Decision on Participation
I wanted to get a large payoff last time.

Your Payoff The Reason for Your Decision on Investment Number
4960

I expected my opponent to invest at least 13.

229

When your opponent did not participate in investment:
I chose 11 to maximize my payoff at early periods. Later I chose a small number to make my opponent's payoff small. It
was fine because my payoff was low, but my opponent's was also low.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
By choosing 7-9, I could get reasonable payoffs on average. Sometimes I chose a large number and did not participate ininvestment, but these choices did not pay. First I planed to never choose participation and let my opponents choose 11
to get 8278 every period. However this plan did not work because my opponents did not allow me to get large payoffs.

230

ID Number = 8, Male, Earnings = 2469 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

You
O
¯

Your
Opponent
O
¯

4

10

5095

Because everybody would choose a small number at the first period.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
6
You
O
¯
6
You

Participation
in investment

Your
Opponent´¯´¯Invest. Num.

Your
OpponentO¯
13

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
For the time being, I chose participation at first.

Your Payoff The Reason for Your Decision on Investment Number

To look at what would happen.
Your Payoff The Reason for Your Decision on Investment Number
1007

Because my payoff and my opponent's are almost same.

PayoffTable

The Reason for Your Decision on Participation
To look at how my opponent would behave.

Your Payoff The Reason for Your Decision on Investment Number
1007

Because my opponent invested nothing.

PayoffTable

The Reason for Your Decision on Participation
To look at how my opponent would behave.

Your Payoff The Reason for Your Decision on Investment Number
6117

PayoffTable

The Reason for Your Decision on Participation
For the time being, I chose participation at first.

Your Payoff The Reason for Your Decision on Investment Number
6478

Investing 7 would be most safe.

PayoffTable

The Reason for Your Decision on Participation
I would like to get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
6478

Because of my success at the last period.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
79Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

231

6

0

PayoffTable

The Reason for Your Decision on Participation
I would like to get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
8271

Because of my success at the last period.

PayoffTable

The Reason for Your Decision on Participation
So far so good.

Your Payoff The Reason for Your Decision on Investment Number
2003

To make my opponent' payoff as small as possible.

PayoffTable

The Reason for Your Decision on Participation
I expected my opponent to be a person of good faith.

Your Payoff The Reason for Your Decision on Investment Number
2003

I do not like to let a selfish person, who only seeks his own payoff, gets alarge payoff.

PayoffTable

The Reason for Your Decision on Participation
I tried to be more patient and chose participation.

Your Payoff The Reason for Your Decision on Investment Number
7340

I stuck to choosing 7.

PayoffTable

The Reason for Your Decision on Participation
I wanted harmony.

Your Payoff The Reason for Your Decision on Investment Number
6478

I wanted to repeat my success at the last time.

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
2003

Because it is easy to compute a payoff.

PayoffTable

The Reason for Your Decision on Participation
Because I could not stand it any longer.

Your Payoff The Reason for Your Decision on Investment Number
706

232

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
3
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
89Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

8

PayoffTable

The Reason for Your Decision on Participation
Because of my failure at the last time.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I have gotten reasonable payoffs by choosing 7.

PayoffTable

The Reason for Your Decision on Participation
I carry out my original intention.

Your Payoff The Reason for Your Decision on Investment Number
3675

Because my opponent would invest around 7, 8, or 9.

PayoffTable

The Reason for Your Decision on Participation
I participated in investment for the present.

Your Payoff The Reason for Your Decision on Investment Number
2386

I wanted to get a higher payoff.

PayoffTable

The Reason for Your Decision on Participation
Because I would like to get a payoff surely.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 8, Male, Earnings = 2469 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
I thought all I need was the first sheet of the payoff tables 1. It was not easy for me to see the supplemental tables, andthey are little meaningful.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
5. If my payoff is the same as my opponent's payoff, I do not care about the absolute value of my payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Initially I intended to participate in investment at all periods. However at many periods my opponents did notparticipate in investment. I was angry with them and they disturbed my rhythm.

6526

Because my opponent would invest around 7, 8, or 9.

(6) How did you choose your investment number when you participated in investment?

PayoffTable

The Reason for Your Decision on Participation

When your opponent participated in investment:

Because I wanted a reasonable payoff safely.

Around 7 or 8 which were most frequently chosen.

Your Payoff The Reason for Your Decision on Investment Number

When your opponent did not participate in investment:

8225

Because my opponent would choose around 7.

I chose numbers so that both my own payoff and my opponent's were moderate.

PayoffTable

The Reason for Your Decision on Participation(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?

I made a gamble at the final period.
Your Payoff The Reason for Your Decision on Investment Number
4904

Because my opponent might attempt to maximize his payoff.

233

I think this experiment ends peacefully if everybody chooses participation and invests around 7 or 8. It is best.
However, this does not hold if someone always chooses non-participation. It is important whether many persons wantpeaceful coexistence and can choose such a choice. There would be no person who invests at least 20 units because hehas no gain. Thus we have to behave steadily.

234

ID Number = 9, Male, Earnings = 2606 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

You
O
¯

Your
Opponent
O
¯

6

9

4850

I attempted to reduce my opponent's payoff and increase my payoff.
However, I did not choose an extreme number.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You
´
¯

You

To see how the other person reacts when I did not participate ininvestment.
Your Payoff The Reason for Your Decision on Investment Number

Your
OpponentO¯

PayoffTable

Your Payoff The Reason for Your Decision on Investment Number
500
PayoffTable

Invest. Num.

68Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
60Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
6The Reason for Your Decision on Participation
Once again, to see how the other person reacts when I did not participate
in investment.

0

O
¯

9

Your Payoff The Reason for Your Decision on Investment Number

6117

Participation
in investment

The Reason for Your Decision on Participation
To see what happens.

13

Your
OpponentO¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation

My opponent may invest 0 when I choose non-participation. From now
on I will choose participation and invest 0 when I want to not participate
in investment.
Your Payoff The Reason for Your Decision on Investment Number
4201

Payoff
Table

Expecting my opponent to invest 0 at the last practice period, I chose anumber so that the difference between my payoff and my opponent's ispermissible.

Invest. Num.
47
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
47
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

98Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

The Reason for Your Decision on Participation

Invest. Num.

To prevent my opponent from knowing that I may not participate ininvestment.

Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯Your Payoff The Reason for Your Decision on Investment Number
2003

I considered the difference between my payoff and my opponent's.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5765

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Because I would like to invest 4, 5, or 6.

8

Invest. Num.
87Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

235

8

6

PayoffTable

The Reason for Your Decision on Participation
The same as above.

Your Payoff The Reason for Your Decision on Investment Number
5812

I optimistically hope that my payoff is high.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2003

I considered the difference between my payoff and my opponent's.

PayoffTable

The Reason for Your Decision on Participation
To leave a possibility that I may invest 0. Also I do not like to give a nonparticipant a high payoff, and everyone would have the same idea.

Your Payoff The Reason for Your Decision on Investment Number
5812

If I invest 4-6, then the other person would invest 7-12.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7250

The same as the above. Further, I chose a number so that my payoff ishigh when my opponent's investment number is 7-12.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above. Investing 8 is optimal for the investment numberof my opponent at the previous period.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

Investing 8 each other would continue.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2003

I considered the difference between my payoff and my opponent's.

236

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
87Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
8
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected my opponent to invest 7-9.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

I expected my opponent to invest 6-8. Then I think investing 8 would be
best when I take account of my own payoff only.

PayoffTable

The Reason for Your Decision on Participation
I chose non-participation and expected my opponent to invest 12 at later
periods.

Your Payoff The Reason for Your Decision on Investment Number
4904
PayoffTable(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
I almost always used payoff table 1 only. It was not easy for me to compare the difference between my payoff and my
opponent's payoff by using payoff table 1. Payoff table 2 was initially helpful to understand amounts of payoffs roughly.
Payoff table 3 was useful to get an image of the payoff structure when making a decision.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
6. Other (please specify) Basically 1 (it is desirable that my payoff is as high, regardless of my opponent's payoff).
However, I also considered my opponent's payoff because I felt mortifying when the difference of payoffs was morethan twice.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment was
greater than the number of periods at which I did not.

Because one might want to make his own payoff high by investing 10-12
when few periods are left.

The reasons for your decisions on participation:

706
The Reason for Your Decision on Participation
The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number

PayoffTable

ID Number = 9, Male, Earnings = 2606 yen

The Reason for Your Decision on Participation
The same as the above. Because of my success at the previous period.

Your Payoff The Reason for Your Decision on Investment Number
8278

I had chosen participation till period 11, because I understood at practice periods that my opponent invested less if I did
not participate. I had not participated since period 2, because I expected that many people would care only of their own
payoff, but not much of my opponent's. By choosing non-participation, I tried to force my opponent to invest 10-12.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
Initially I chose small numbers that seem to lead high payoffs. However, investing 7-9 was most often observed so thatmy payoff and my opponent's payoff were similar. Therefore I chose 8 which would be a best response to suchinvestment numbers.
When your opponent did not participate in investment:
I always chose 6.
opponent's.

By choosing this number, I could compromise on the difference between my payoff and my(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
I did not understand what to do at early periods. However, I thought it would be good to choose 7-9 at middle periods
and non-participation at later periods. My strategy for later periods was successful, but there might be a better strategy
for later periods.

237

238

ID Number = 10, Male, Earnings = 1920 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

4

6

2587

To understand what my opponent think because this is the first practiceperiod.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation´¯Your Payoff The Reason for Your Decision on Investment Number

To see what my opponent will do.
Your Payoff The Reason for Your Decision on Investment Number
6117
Payoff
Table

O
¯

Your
Opponent
O
¯

9

8

You

You
O
¯

Your
OpponentO¯

00Invest. Num.
2
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment
¯
¯
7

6

The Reason for Your Decision on Participation
The probability that my opponent participates would be 50% because thisis the first practice period.

13

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
To avoid the situation ´´ in which the payoff is worst.

Your Payoff The Reason for Your Decision on Investment Number
4512

Payoff
Table

Because my payoff is high when my opponent's investment number is thesame as mine.
The Reason for Your Decision on Participation
The same as practice 3.

Your Payoff The Reason for Your Decision on Investment Number
500

To see what my opponent will do.

PayoffTable

The Reason for Your Decision on Participation
To put a check on my opponent's movements.

Your Payoff The Reason for Your Decision on Investment Number
1186
PayoffTable

The Reason for Your Decision on Participation
Because my opponent at period 1 did not make the best investment
decision leading to the highest payoff.

Your Payoff The Reason for Your Decision on Investment Number
5681

I expected my opponent to choose 9.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

5

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

96Period 6 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 9 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.

239

8

PayoffTable

The Reason for Your Decision on Participation
If my opponent participates, then he has to invest 11 units to get thehighest payoff. Then I can get the payoff of 8278.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
Because I am afraid that my opponent might choose ´.

Your Payoff The Reason for Your Decision on Investment Number
5064

Actually, if everyone chooses 8 at every period, then we can get at least
3000 yen after the experiment, according to my calculation.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5765

Since my opponents have chose small investment numbers, I would
suffer a loss if my investment number were small.

PayoffTable

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number
2017
PayoffTable

The Reason for Your Decision on Participation
I do not understand why subjects #3 and #14 took such behavior. So I
will choose participation randomly.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation
I do not understand why my opponent at period 8 took such behavior.

Your Payoff The Reason for Your Decision on Investment Number
706

240

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

05Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
07Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
38
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

98

PayoffTable

The Reason for Your Decision on Participation

It would be good to participate and invest 0. My payoff is 1050-2000 if
my opponent investment's number is 3 or 4, and my payoff is 4000 if it is5.
Your Payoff The Reason for Your Decision on Investment Number
2578

Because of the reason mentioned above. But if my opponent's investment
number is always 4 or 5, I cannot expect a large payoff.

PayoffTable

The Reason for Your Decision on Participation
The previous method seems to be good.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number
6383

If my opponent's investment number is 4-6, then I should choose 3-5.

PayoffTable

The Reason for Your Decision on Participation

ID Number = 10, Male, Earnings = 1920 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
I used payoff table 1 only. The remaining eight tables were not necessary. I do not understand why my payoff is highest
when my investment number is 2 and my opponent's investment number is 24 in the payoff table for practice.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
6. Others (please specify). Initially, 3 (it is desirable that both my payoff and my opponent's payoff are ashigh as possible). However, I felt that my opponents' views would be 1 (it is desirable that my payoff is as high,regardless of my opponent's payoff) or 2 (if my payoff is higher than my opponent's payoff, I do not care about theabsolute value of my payoff, even when the difference between my payoff and my opponent's is small). So I changed to2.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:

Your Payoff The Reason for Your Decision on Investment Number
2658

I have no choice when my opponent did not participate.

If everyone invests around 8, his payoff is surely 100,000. However, I sometimes decided to choose non-participation
just on the spur of the moment.

PayoffTable

The Reason for Your Decision on Participation(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:

Your Payoff The Reason for Your Decision on Investment Number
2658

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

At early periods, I chose 7-9 because both my payoff and my opponent's payoff were steady.
At later periods, I chose 0 or 3 because my opponents chose 4, 5, or 6 most often.
When your opponent did not participate in investment:
At every period, I chose 11 to maximize my payoff.

Your Payoff The Reason for Your Decision on Investment Number
7250(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
I can say nothing. In the current situation, it would be mentally healthy to be unconcerned with investment rather thanto participate in investment.

241

242

ID Number = 11, Male, Earnings = 2391 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.

Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

12

13

6766

By investing 12, I can get a reasonable payoff no matter of what my
opponent's investment number is.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13

You
´
¯

You
O
¯

Your
OpponentO¯

I would like to try many things in practice.
Your Payoff The Reason for Your Decision on Investment Number
1631

My opponent gets 6117, while I only get 1613. If I invest 0, then mypayoff and my opponent's are the same and they are 500. But I chose thisnumber in practice.

PayoffTable

The Reason for Your Decision on Participation
To see what my opponent will do. He probably would choose either 13
or 0.

Your Payoff The Reason for Your Decision on Investment Number

Your
Opponent´¯

Payoff
Table

0

The Reason for Your Decision on Participation
Non-participation is not fun. This is a practice period and so I want to try
participation.

Your Payoff The Reason for Your Decision on Investment Number
500

Invest. Num.
66
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
7Your Payoff The Reason for Your Decision on Investment Number

6117

0

The Reason for Your Decision on Participation
I participated for the time being.

13

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

Payoff
Table

Payoff
Table

Because I will be in trouble if my opponent will choose ´ at many times in
the actual experiment, I try to force my opponent to realize that nonparticipation is not beneficial. My current payoff is only 500, but this is apractice period. Basically, choosing 13 is best at this time, but choosing
such a number would be an investment for the future return.

The Reason for Your Decision on Participation

Choosing O would be better since the situation ´´ may happen. If bothchoose O, then I could get a higher payoff. Therefore, unless my
opponents choose ´ at many times, I continue to choose O. But if my
opponents choose O at many times, I may choose ´.
Your Payoff The Reason for Your Decision on Investment Number
5515

Because I expected my opponent to choose around 12 at the first time.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

I expected my opponent to choose 6-8. Then my payoff will be about
5500.

243

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

4

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
2
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.
85Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

96Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

910Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

11

8

PayoffTable

The Reason for Your Decision on Participation
The same as the above. I do not like the case ´´.

Your Payoff The Reason for Your Decision on Investment Number
4281

I still believe my opponent to choose 6-8 this time. The person at theprevious period was strange.

PayoffTable

The Reason for Your Decision on Participation
Because most of my opponents chose O, I want to get 8272. I'll take achance on it.

Your Payoff The Reason for Your Decision on Investment Number
2017

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I was shocked at the result at the previous period. I will get a large payoff
this time for sure.

Your Payoff The Reason for Your Decision on Investment Number
1186

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

Because there seems to be a public tendency to regard non-participationas unacceptable. Choosing O would be better. I go back to my original
intention.
Your Payoff The Reason for Your Decision on Investment Number
5064

My opponent would invest around this number.

PayoffTable

The Reason for Your Decision on Participation
I will continue O for a while. My aim is to get 7000.

Your Payoff The Reason for Your Decision on Investment Number
5767

I hope that everyone realizes that both payoffs are reasonable byinvesting 8-12.

PayoffTable

The Reason for Your Decision on Participation
The same as the above. My aim is to get 8000.

Your Payoff The Reason for Your Decision on Investment Number
8951

Investing 12 is best, but my opponent seems not to do so. Therefore I
chose 9.

PayoffTable

The Reason for Your Decision on Participation
Because of my success at the last period.

Your Payoff The Reason for Your Decision on Investment Number
6765

I hope that everyone understand that investing 12 is best.

244

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
107Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
108Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
98Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

PayoffTable

The Reason for Your Decision on Participation
My opponent would not choose ´. I want to get a higher payoff.

Your Payoff The Reason for Your Decision on Investment Number
6343

Choosing 12 is best, but I chose 10 because I am not confident.

PayoffTable

The Reason for Your Decision on Participation
My opponent would not choose ´. I would be able to get 6000.

Your Payoff The Reason for Your Decision on Investment Number
7056

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
My opponent would not choose ´. My goal is to get 9000.

Your Payoff The Reason for Your Decision on Investment Number
1536

I made my opponent's payoff low because I was angry with him/her.

PayoffTable

The Reason for Your Decision on Participation

My opponent would not choose ´. Choosing ´ does not lead to a highpayoff.
Your Payoff The Reason for Your Decision on Investment Number
2003

I got mad at my opponent, but I wanted to keep 2000.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7250

I want to get a reasonable payoff safely.

PayoffTable

The Reason for Your Decision on Participation
I would be sorry for my opponent if I chose ´ at the final period.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because most of my opponents chose 7 or 8.

245

ID Number = 11, Male, Earnings = 2391 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
The red payoff tables (payoff table 1, 1-1, and 1-2) are sufficient. The others are wasteful. I did not look at the tables withinequalities that are difficult to see. First, I understood that my payoffs are large in the southwest part of the payoff table
1. Then I made a decision by looking at each number in it.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
I thought that non-participation was not good, since the situation was worst if my opponent did not participate, either.
When my opponent chose non-participation, I chose a number so that my opponent's payoff was small. Because my
opponent might take such behavior, I decided to choose participation. In fact, my opponents did so when I did notparticipate two times. Therefore I felt everyone had the same idea and chose participation afterward.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I expected my opponent to choose 8-12 and chose such numbers.
When your opponent did not participate in investment:
I made my opponent's payoff low.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
Choosing 8 at all periods would be best. Choosing 8 is the number maximizing my payoff if my opponent also chooses
8.
I can get 5000 points surely by choosing 8.

246

ID Number = 12, Male, Earnings = 2559 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment

You
´
¯

You
O
¯

You
´
¯

You

Invest. Num.

O¯

PayoffTable

Your Payoff The Reason for Your Decision on Investment Number
1631

I invest 13 without doubt.

PayoffTable

The Reason for Your Decision on Participation
I expected my opponent to choose participation, and I outwitted him/herby doing just the opposite.

Your Payoff The Reason for Your Decision on Investment Number
854

Your
Opponent´¯

PayoffTable

Invest. Num.
87Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
6The Reason for Your Decision on Participation
I anticipated that many people would choose non-participation.

4

13

6

Your Payoff The Reason for Your Decision on Investment Number

Your
Opponent´¯

YourOpponentO¯

The Reason for Your Decision on Participation
I would like to see what happens at the first period. If my opponent
invest a large amount, I am lucky.

514

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

Payoff
Table

1

13

Invest. Num.
Practice 4

Participation
in investment

Your
OpponentO¯

The Reason for Your Decision on Participation
I expected my opponent at practice 3 to invest 13, but he/she actuallyinvested 4. I decided to participate in investment on a whim.

Your Payoff The Reason for Your Decision on Investment Number
1631

The same as period 2. My opponent got 6117. I am vexed at it.

PayoffTable

The Reason for Your Decision on Participation
I can expect a high payoff in the pattern OO.

Your Payoff The Reason for Your Decision on Investment Number
6526

I anticipated my opponent to choose a small investment number.

PayoffTable

The Reason for Your Decision on Participation
I would like to avoid ´´.

Your Payoff The Reason for Your Decision on Investment Number
5515

1) My opponent would expect me not to choose a large investment
number. 2) I expected my opponent to choose a number deviating fromthe maximum number.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
97
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
97
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
98Period 8 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.
Period 9 of the Actual Experiment
You
Your
Opponent
Participation´´
in investment¯¯
Invest. Num.

247

PayoffTable

The Reason for Your Decision on Participation
I will choose participation unless something serious comes up.

Your Payoff The Reason for Your Decision on Investment Number
6481

Choosing around 7-9 seems to be safe.

PayoffTable

The Reason for Your Decision on Participation

I hope that ´O will happen. My opponent will invest 11 and I will get
8278. This is my strategy. However, I am afraid of ´´.
Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
The strategy ´O. My opponent will be mad if he/she chooses O.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation

It's important to know when to quit ´. It is about time that I meet theperson who chooses ´.
Your Payoff The Reason for Your Decision on Investment Number
6481

Because this is safe.

PayoffTable

The Reason for Your Decision on Participation
I am afraid of ´´.

Your Payoff The Reason for Your Decision on Investment Number
7250

Because this is safe.

PayoffTable

The Reason for Your Decision on Participation
I am prepared for ´´. It is fine that both are regretful.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I do not like ´´, but I cannot refuse the magical power of ´ O.

Your Payoff The Reason for Your Decision on Investment Number
706

248

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
1
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

9

PayoffTable

The Reason for Your Decision on Participation
I prefer ´´ to O´.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation´ O is profitable. But I am afraid that my opponent may invest 0 to annoyme.
Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I stick to ´O persistently.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation

I pray that ´O will happen in all the remaining periods and my opponent
will invest 11.
Your Payoff The Reason for Your Decision on Investment Number
3244

I cannot understand why 6 was chosen.

PayoffTable

The Reason for Your Decision on Participation

ID Number = 12, Male, Earnings = 2559 yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
It was good that I could coordinate my payoff and my opponent's by comparing the table O´ with the table ´O.
For the table OO, a lot of my opponents chose 7 or 8. There was no investment more than 10, nor no investment less thanor equal to 5.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
4. If I can make my opponent's payoff as small as possible, it is fine that my payoff is moderate.
I regret that I missed to get the chance ´O (encountered the case ´´) two times. Since they happened in early rounds, my
opponents might invest for their own benefits and I could receive 8278. "0" and "1" were chosen one time each to spite
me. Also "6" was chosen one time. I do not understand why even now. Does he/she think that the difference between
his/her payoff and his/her opponent's matters?
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
4. I participated in investment several times, but the number of periods at which I did not participate in investment was
greater than the number of periods at which I did.
The reasons for your decisions on participation:

Hopefully, ´O will happen and I will get 8278.
Your Payoff The Reason for Your Decision on Investment Number
905
PayoffTable

I was confident that by doing the strategy ´O, the probability that I got 8278 was not small. However, out of 10 trials, I
succeeded only 4 times. At the other trials, I encountered ´´, or my opponents spited me.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:

The Reason for Your Decision on Participation

9. I often won by choosing 7-9. But I thought after the experiment that choosing 8 seems to be good.

At last I realize that one often bothers his/her opponent even by ignoring
his/her own profit. It is too late.

When your opponent did not participate in investment:

Your Payoff The Reason for Your Decision on Investment Number
5907

O´ never happened.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
To make a reasonable profit safely, (i) invest 8 when the case OO happens, and (ii) invest 11 when the case O´ happens.

249

250

ID Number = 13, Male, Earnings = 2766
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

6

8

4201

I anticipated my opponent to invest at least 15.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation´¯

The Reason for Your Decision on Participation
Participation seems to be more beneficial.

Your Payoff The Reason for Your Decision on Investment Number

To see what happens by choosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number

61416
Payoff
Table

O
¯

Your
Opponent
O
¯

10

13

7573

I expected my opponent would not invest a large number.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

You

´
¯

13

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

Payoff
Table

11

The Reason for Your Decision on Participation
Because of my failure at period 2.

Your Payoff The Reason for Your Decision on Investment Number

I suppose that my opponent invests 13.
Your Payoff The Reason for Your Decision on Investment Number
6117

PayoffTable

The Reason for Your Decision on Participation
I expected my opponent to invest 11.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I suppose that my opponent invests 11.

Your Payoff The Reason for Your Decision on Investment Number
8278

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
69Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
65
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

251

6

PayoffTable

The Reason for Your Decision on Participation
To get a reasonable payoff safely.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
To recover my failure at period 1.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff is highest according to Table 2.

PayoffTable

The Reason for Your Decision on Participation
Because my opponent may not participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff is highest.

PayoffTable

The Reason for Your Decision on Participation
To see what happens.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I just tried this.

Your Payoff The Reason for Your Decision on Investment Number
8209

I expected my opponent to invest around 10.

PayoffTable

The Reason for Your Decision on Participation
To get a relatively large payoff.

Your Payoff The Reason for Your Decision on Investment Number
4762

I expected my opponent to invest at least 10.

PayoffTable

The Reason for Your Decision on Participation
Because I can get a higher payoff by non-participation.

Your Payoff The Reason for Your Decision on Investment Number
3244

252

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

6

PayoffTable

The Reason for Your Decision on Participation
I expected my opponent (to choose participation).

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 13, Male, Earnings = 2766
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.

6478

I expected my opponent to invest at least 10.

PayoffTable

The Reason for Your Decision on Participation(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?

I may get a high payoff.

The payoff table 1 is enough.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I can get a high payoff when my opponent chooses around 10.

PayoffTable

The Reason for Your Decision on Participation
Non-participation is better because my opponent chooses not more than
9.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I expected my opponent to invest 11.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

1. It is desirable that my payoff is as high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Non-participation seems to be more beneficial, but continuing it is boring.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:

The Reason for Your Decision on Participation

I expected that my opponents' investment numbers would be similar to the numbers I would like to choose.

I think my opponent would choose participation.

When your opponent did not participate in investment:

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?

The Reason for Your Decision on Participation
Because this is the final period.

I chose a number making my own payoff high.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
I think it is good to choose non-participation at all periods. My payoffs were around 8000 at 10 out 15 periods. Nonparticipation is safe, although it is not fun. Because my opponent also seeks to get a high payoff, both rarely invest morethan 8. By investing at most 8, I can only get a payoff less than 8000.

Your Payoff The Reason for Your Decision on Investment Number
5681

My opponent may choose a large investment number.

253

254

ID Number = 14, Male, Earnings = 1728 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
O
¯

24

4

500

I choose the highest number because my opponent would choose 10-15.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
9

12

PayoffTable

The Reason for Your Decision on Participation
To see what happens by participation.

Your Payoff The Reason for Your Decision on Investment Number

I misunderstood the payoff structure and hence chose participation once
more. My opponent's payoff was large because I chose a high number.
Your Payoff The Reason for Your Decision on Investment Number
7085

I chose a number that was rather less than the middle number in an
attempt to make my opponent's payoff not large and my payoff a bit
large.

Practice 3
You
Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

´
¯

Your
OpponentO¯

Payoff
Table

O
¯

Your
Opponent
O
¯

10

12

4

10

7

The Reason for Your Decision on Participation
At period 3 I thought that I could not expect a large payoff by nonparticipation, unless my opponent makes a mistake.

Your Payoff The Reason for Your Decision on Investment Number
6873

My opponent would choose a small number. For the time being, I can geta reasonable payoff by choosing a middle number.

PayoffTable

The Reason for Your Decision on Participation
I can expect a high payoff by participation.

Your Payoff The Reason for Your Decision on Investment Number
1536

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

Your Payoff The Reason for Your Decision on Investment Number
854

You

The Reason for Your Decision on Participation
I would like to know what happens by non-participation and what my
opponent's interpretation of payoff 2 was.

4

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

Payoff
Table

PayoffTable

By choosing this number, my payoff is moderate and the difference
between my payoff and my opponent's is not large.
The Reason for Your Decision on Participation
Anyway, non-participation is meaningless. I am frustrated because of theresult at period 2. I was disgusted with it.

Your Payoff The Reason for Your Decision on Investment Number
6343

My goal is to get 80,000 points overall. To achieve it, I want to get 8,000
points this time.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

4

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
102Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
127Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

4

Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
1
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

255

3

0

PayoffTable

The Reason for Your Decision on Participation
I want to get a large payoff.

Your Payoff The Reason for Your Decision on Investment Number
4590

Because my opponent would choose 7-10 at the beginning of the game. I
seek a high payoff.

PayoffTable

The Reason for Your Decision on Participation
Participation is more beneficial than non-participation.

Your Payoff The Reason for Your Decision on Investment Number
1536

I chose a number so that my opponent does not get a large payoff and I
get a reasonable payoff.

PayoffTable

The Reason for Your Decision on Participation
Anyway, participation is great.

Your Payoff The Reason for Your Decision on Investment Number
3465

Anyway I want to get the average payoff.

PayoffTable

The Reason for Your Decision on Participation
Because I want to get a large payoff this time.

Your Payoff The Reason for Your Decision on Investment Number
5800

I made my opponent wealthy and will wait until the later periods.

PayoffTable

The Reason for Your Decision on Participation
To make a profit by investment.

Your Payoff The Reason for Your Decision on Investment Number
1536

I punished my opponent by making his/her payoff low so that he/shewill never think non-participation in investment.

PayoffTable

The Reason for Your Decision on Participation
I want to know what happens by non-participation. My opponents havechose non-participation three times in a row.

Your Payoff The Reason for Your Decision on Investment Number
905
PayoffTable

The Reason for Your Decision on Participation
As I expected, I had nothing good by non-participation.

Your Payoff The Reason for Your Decision on Investment Number706

To prevent my opponent from making a profit.

256

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
10
6Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

48Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

7

PayoffTable

The Reason for Your Decision on Participation
Because my payoff by participation is higher than that by nonparticipation.

Your Payoff The Reason for Your Decision on Investment Number
5677

I would like to get a reasonable payoff.

PayoffTable

The Reason for Your Decision on Participation
Participation is good.

Your Payoff The Reason for Your Decision on Investment Number706

To warn him/her. I am really mad!

PayoffTable

The Reason for Your Decision on Participation
We have to participate in investment to make a profit.

Your Payoff The Reason for Your Decision on Investment Number
6751

Because I expected my opponent to choose 7-9 in an attempt to get the
average payoff.

PayoffTable

The Reason for Your Decision on Participation
We cannot change the fact that participation is more profitable.

Your Payoff The Reason for Your Decision on Investment Number
706

I have no payoff to give you!

PayoffTable

The Reason for Your Decision on Participation
Participation is most profitable for me.

Your Payoff The Reason for Your Decision on Investment Number
5766

PayoffTable

I expected my opponent to choose a number in an attempt to get 5,0008,000.
The Reason for Your Decision on Participation
Because participation is more profitable than non-participation.

Your Payoff The Reason for Your Decision on Investment Number
6339

ID Number = 14, Male, Earnings = 1728 yen.
(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 2) in Practice(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
I referred to the payoff table 1 when deciding investment numbers. Anyway, I am pretty sure that participation is better
than non-participation.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
6. Others (please specify).
It is good that my payoff is about the average and my opponent's payoff is around my payoff (±1000).
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Because my payoff is higher by choosing participation than by choosing non-participation.
experience that when I choose non-participation, nobody lets his/her opponent get a high payoff.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I chose a number so that my payoff is 5,000-8,000.
When your opponent did not participate in investment:
I chose 4 in the first half and 0 in the second half to prevent my opponent from choosing non-participation.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
It is best to always participate in investment and then invest a number in an attempt to get a payoff around the average(4,000-8,000), no matter what my opponent gets. This is because my opponent invests only 4-8.

To seek a moderate payoff. My payoff would not choose a number suchthat my payoff becomes very large.

257

I learned from my

258Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

ID Number = 15, Female, Earnings = 3062.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.

You
O
¯

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

7

9

5000

Because I expect that my opponent would choose a middle investment
number at the first time.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
OpponentO¯

56Because I seek to make a profit by participation.

Invest. Num.

Your Payoff The Reason for Your Decision on Investment Number

Because I seek to make a profit by participation once more.

2849

I expected my opponent’s investment number to be 13-21.
supplemental table 1-1.

By thePractice 3
You
Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

O
¯

Your
Opponent
O
¯

8

13

8018

I expected my opponent’s investment number to be 7-12.
supplemental table 1-1.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13

6

4

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

10

The Reason for Your Decision on Participation
Because the result at the second period was not good, I would like to try t
it once more.

Your Payoff The Reason for Your Decision on Investment Number
By theBecause the result at the third period was not bad.
Your Payoff The Reason for Your Decision on Investment Number
1631

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

Payoff
Table

PayoffTable

My opponent did not participate in investment. By the payoff table 2.
My opponent gets a high payoff, but how much my payoff is takes
priority.

The Reason for Your Decision on Participation
I anticipated my opponent would also choose participation.

Your Payoff The Reason for Your Decision on Investment Number
4078

PayoffTable

I expected my opponent's investment number to be 10-18.
supplemental table 1-1.

By theThe Reason for Your Decision on Participation
The result at period 1 was not good, but I wanted to try it one more.

Your Payoff The Reason for Your Decision on Investment Number
9270

This seems to be safe.

259

6Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

Your Payoff The Reason for Your Decision on Investment Number

7

5

8

Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
66
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
9
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The Reason for Your Decision on Participation
Because the outcome at the last period was good.

Your Payoff The Reason for Your Decision on Investment Number
5681

I want to try the same number as that at the last period one more, because
it was not bad.

PayoffTable

The Reason for Your Decision on Participation
The results at the last three periods were not so good, but I will get a highpayoff this time for sure.

Your Payoff The Reason for Your Decision on Investment Number
7038

By choosing a number that is smaller than my opponent's, I want to get alarger payoff than my opponent does.

PayoffTable

The Reason for Your Decision on Participation
Because I feel that participation and choosing an investment number are
fun.

Your Payoff The Reason for Your Decision on Investment Number
5515

From my experience at the last four periods.

PayoffTable

The Reason for Your Decision on Participation
Nonparticipation flashed across my mind, but I did not choose it.

Your Payoff The Reason for Your Decision on Investment Number
5681

This is safe. I didn't feel like running the risk.

PayoffTable

The Reason for Your Decision on Participation
Because the results were not satisfactory so far.

Your Payoff The Reason for Your Decision on Investment Number
7345"8" seems to be good.

PayoffTable

The Reason for Your Decision on Participation
Because I cannot find any reason why I should stop participation.

Your Payoff The Reason for Your Decision on Investment Number
2523

I considered both my payoff and my opponent's.

PayoffTable

The Reason for Your Decision on Participation
I expected my opponent to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6478

I expected my opponent to choose a middle investment number.

260

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
8
10Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

9

PayoffTable

The Reason for Your Decision on Participation
Because I want to try participation once more.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected my opponent to choose a safe number.

PayoffTable

The Reason for Your Decision on Participation
To make a profit by participation.

Your Payoff The Reason for Your Decision on Investment Number
9168

Because I wanted to try "8" once more.

PayoffTable

The Reason for Your Decision on Participation
The result at the last period was not bad. Once more!

Your Payoff The Reason for Your Decision on Investment Number6339

I expected my opponent's investment number to be a middle number.

PayoffTable

The Reason for Your Decision on Participation
To make a profit by participation.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 15, Female, Earnings = 3062.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
I looked at only the payoff table 1 undoubtedly when both my opponent and I participated in investment.
I looked at not only the payoff table 2, but also the payoff table 3 when I participated in investment, but my opponent
did not.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
6. Others (please specify).
When both participated in investment, 1. (it is desirable that my payoff is as high, regardless of my opponent's payoff).
When I participated in investment, but my opponent did not, I considered both my payoff and my opponent's.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
1. I always participated in investment.
The reasons for your decisions on participation:
Because I sought to get a larger payoff by choosing participation.

7340

Because I expected my opponent to choose a safe number.

(6) How did you choose your investment number when you participated in investment?

PayoffTable

The Reason for Your Decision on Participation

When your opponent participated in investment:

I anticipated my opponent to participate in investment.

I expected what my opponent's investment number was, and chose a safe number.

Your Payoff The Reason for Your Decision on Investment Number

When your opponent did not participate in investment:

6478

Because choosing "7" was not bad at the last period.

I considered both my payoff and my opponent’s by referring to both the payoff tables 2 and 3.

PayoffTable

The Reason for Your Decision on Participation(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?

Because my opponent would also choose participation.
Your Payoff The Reason for Your Decision on Investment Number
2523

My opponent would not invest a large amount unless he/she takes a positive attitude toward investment. It is good to
expect the opponent's number and choose a safe number.

Consider my payoff and my opponent's.

261

262

ID Number = 16, Male, Earnings = 2228yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

You
O
¯

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

4

24

23849

Because I expected my opponent to choose a large investment number.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

7

8

4473

I expected my opponent's investment number to be 10-12 and chose thenumber leading to the largest payoff for those numbers.

You

PayoffTable

The Reason for Your Decision on Participation

Because I anticipated that my payoff would be larger by participation
than by non-participation.
Your Payoff The Reason for Your Decision on Investment Number

Because I expected my opponent to participate in investment.
Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

4

10

5095

I believed my opponent to invest at least 16.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment´¯

Invest. Num.

13

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
46
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

Because my opponent would also choose participation.
Your Payoff The Reason for Your Decision on Investment Number

Because I am tired of choosing participation. I take a break.
Your Payoff The Reason for Your Decision on Investment Number
6117

PayoffTable

The Reason for Your Decision on Participation
I would like to get a high payoff by participation.

Your Payoff The Reason for Your Decision on Investment Number
4960

I expected my opponent to invest at least 10.

PayoffTable

The Reason for Your Decision on Participation
I know by intuition that my opponent also participates in investment.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff was maximized.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
47
Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
2
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

263

3

PayoffTable

The Reason for Your Decision on Participation
Because I thought that I should choose participation.

Your Payoff The Reason for Your Decision on Investment Number
5812

I expected my opponent to invest at least 10.

PayoffTable

The Reason for Your Decision on Participation
I expected my opponent to choose participation and invest "11".

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation"Please participate in investment!" I hope my opponent to do so.

Your Payoff The Reason for Your Decision on Investment Number
7237

Because I expected my opponent to choose 6-8.

PayoffTable

The Reason for Your Decision on Participation
Because I do not like to wait anymore.

Your Payoff The Reason for Your Decision on Investment Number
7340

Lucky "7". My opponent's number is 6-8.

PayoffTable

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number
6478

Because my opponent' investment number is 10.

PayoffTable

The Reason for Your Decision on Participation
I now understand that waiting is important.

Your Payoff The Reason for Your Decision on Investment Number
1186
PayoffTable

The Reason for Your Decision on Participation
I do not like to wait anymore!

Your Payoff The Reason for Your Decision on Investment Number
1297

Because I do not like that my opponent gets a large payoff.

264

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
70Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

72

Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
2
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

8

PayoffTable

The Reason for Your Decision on Participation
I do not understand the situation.

Your Payoff The Reason for Your Decision on Investment Number
3675

Because I expected my opponent to invest 10.

PayoffTable

The Reason for Your Decision on Participation
I do my best. Help me, please!

Your Payoff The Reason for Your Decision on Investment Number
2210

Because my opponent's ID number is 10, his/her investment number
would also be 10.

PayoffTable

The Reason for Your Decision on Participation
I have to choose participation. There is no other way.

Your Payoff The Reason for Your Decision on Investment Number
5681

I continue to choose 7.

PayoffTable

The Reason for Your Decision on Participation
I cannot wait at this period.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 16, Male, Earnings = 2228yen(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
The payoff table 1 shows that my payoff is larger as my opponent s investment number is larger and my investment
number is smaller. However, because my opponents' investment numbers were actually 6-8, I had to choose 6-8.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
6. Others (please specify).
Almost always, 5 (if my payoff is the same as my opponent's payoff, I do not care about the absolute value of my payoff).
When my opponent did not participate and my payoff was low, I made my opponent's payoff low.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Because I thought at some periods that non-participation might lead to a high payoff.

1072

My opponent is the worst person.

(6) How did you choose your investment number when you participated in investment?

PayoffTable

The Reason for Your Decision on Participation

When your opponent participated in investment:

Please help me. I chose participation.

Almost always, 7.

Your Payoff The Reason for Your Decision on Investment Number

When your opponent did not participate in investment:

7340

I believed my opponent's investment number to be 10.

2 or 3.

PayoffTable

The Reason for Your Decision on Participation(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?

I participated in investment at the final period.
Your Payoff The Reason for Your Decision on Investment Number
7340

I have decided to choose 7 at the final period.

265

If my opponent's investment is large, then I can get a large payoff even by choosing a small investment number.
However, because my opponent would choose a number between 6 and 8, it is good to choose a number so that my
payoff is maximized for such a number and my payoff and my opponent’s payoff are similar.

266

ID Number = 17, Female, Earnings = 2512 yen.
Practice 1

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.

8

6

Practice 2

Participation
in investment
Invest. Num.
Practice 3

You

You
´
¯

The Reason for Your Decision on Participation

In the case in which I do not participate in investment, my payoff is 500 if
my opponent does not participate, either, and I expected that my payoff
would be small even if he/she does.
Your Payoff The Reason for Your Decision on Investment Number
3405

Payoff
Table

Because I expected my opponent to invest around 10 safely at the firsttime, I set my investment number at 8.
The Reason for Your Decision on Participation
I would like to try non-participation at practice. Also my payoff at period
1 was not so large.

Your Payoff The Reason for Your Decision on Investment Number

1

514
PayoffTable

Participation
in investment

O
¯

Your
OpponentO¯

Invest. Num.
Practice 4

10

4

2708

I chose this number without careful consideration.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

You

Your
OpponentO¯

PayoffTable´¯

Invest. Num.

0

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

6

The Reason for Your Decision on Participation

Because I noticed that if I do not choose participation, my opponent
attaches greater importance to the difference between my payoff andhis/her payoff than to the absolute value of his/her own payoff.
Your Payoff The Reason for Your Decision on Investment Number

Because I wanted to know whether or not my opponent attaches
importance to the difference between my payoff and his/her payoff when
I choose non-participation.
Your Payoff The Reason for Your Decision on Investment Number
500

PayoffTable

Your Payoff The Reason for Your Decision on Investment Number
2017

8

6

Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
66
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
62
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

The Reason for Your Decision on Participation
I wanted to try to participate in investment this time.

Your Payoff The Reason for Your Decision on Investment Number
5515

Invest. Num.

The Reason for Your Decision on Participation
Because I wanted to know whether or not non-participation is notbeneficial.

Payoff
Table

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

I chose 6 so that my number and his/her number would be similar.

Invest. Num.
1
6
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

267

6

6

PayoffTable

The Reason for Your Decision on Participation
Because I expected my opponent to choose participation.

Your Payoff The Reason for Your Decision on Investment Number
5766

I expected my opponent to invest 4-6, and I chose a number to maximize
my payoff. I did not care about the difference between my payoff and my
opponent's.

PayoffTable

The Reason for Your Decision on Participation
If I choose participation, then my opponent will also participate, and 6-8
will be chosen constantly. It is tedious.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation
Because I want to get a reasonable payoff safely this time.

Your Payoff The Reason for Your Decision on Investment Number
5515

I chose 6 because I expected my opponent to choose 6.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2913

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
To get a larger payoff.

Your Payoff The Reason for Your Decision on Investment Number
706

I chose 0 because my opponent did not participate.

PayoffTable

The Reason for Your Decision on Participation
To see how my opponent behaves by choosing participation.

Your Payoff The Reason for Your Decision on Investment Number
3718

I chose 1 to make a feint.

PayoffTable

The Reason for Your Decision on Participation
Because participation is more profitable.

Your Payoff The Reason for Your Decision on Investment Number
5515

Because I expected my opponent to choose 6.

268

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
66
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

9

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5515

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

Because my opponents' investment numbers were 8 three times in a row,
I also changed my investment number to 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8225

The same as the above.

269

ID Number = 17, Female, Earnings = 2512 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
I referred to the red payoff tables in particular. I hardly used the payoff tables for the cases of non-participation, because
the number that the non-participation cases happened is small.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
6. Others (please specify). I changed it on a whim.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
Because I wanted to know how my opponents reacted when I did not participate in investment.
Because I felt tedious when my opponents had chosen 6 constantly, I chose non-participation in the middle of theexperiment.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
At the first half of the experiment, I tried to take various behaviors to see how my opponents reacted or to compete withthem. However, at the second half, I had continuously chosen 6-8, taking account of my payoff.
When your opponent did not participate in investment:
I was angry at non-cooperative behavior of my opponent, and I chose the smallest number 0 to set his/her payoff at thesame as my payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
It is the best to seek my own payoff. It is silly to choose an investment number so that both my payoff and my
opponent's are low in an attempt to compete with him/her. Because non-participation did not lead to a good result, it isgood to choose an investment number so that both my payoff and my opponent's are high. However, because my
opponent would try to compete with me, it is the best to choose 6-8.

270

ID Number = 18, Female, Earnings = 2092 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

Your
Opponent
´
¯

1
You

Because participation would be more profitable than non-participation.
Your Payoff The Reason for Your Decision on Investment Number
513

Because this is better than getting 500.

PayoffTable

The Reason for Your Decision on Participation

O
¯
6

8

4201

Because 6 = 24/4 is the average number.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

Your
Opponent
O
¯

13

8

3981

Because my payoff is the highest if my opponent chooses 0.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
0

0

0

0

To see whether or not my opponent participates. Participation would be
more beneficial than non-participation.
Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
500

Because my opponent might invest all remaining units at the last period.

PayoffTable

The Reason for Your Decision on Participation
To confuse my opponent by participation.

Your Payoff The Reason for Your Decision on Investment Number
706

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation

Your
OpponentO¯

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

PayoffTable

7

PayoffTable

I invested nothing because my opponent did not participate ininvestment.
The Reason for Your Decision on Participation
Because I can choose a number between 0 and 24 by participation.

Your Payoff The Reason for Your Decision on Investment Number
4018

Because I expected my opponent to select a large investment number at
early periods.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
07Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
38
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

10

Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
2
6
Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

271

2

3

7

PayoffTable

The Reason for Your Decision on Participation
Because participation is more profitable.

Your Payoff The Reason for Your Decision on Investment Number
4018

I chose a small investment number in the middle of the experiment.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6383

It is good to select a small number if my opponent selects a small number.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8130

Because I expected my opponent to choose a small number, it is profitable
to choose a small number.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4171

It is profitable to choose small numbers each other.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

Because my opponent selected non-participation.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5440

It is profitable to choose small numbers each other.

272

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
3
7
Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
3
7
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
38
Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
2
5
Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
86Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

11

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5440

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5440

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6383

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
3432

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

I can get a reasonable payoff most safely by choosing around 8.

PayoffTable

The Reason for Your Decision on Participation

ID Number = 18, Female, Earnings = 2092 yen.
(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 14
) in Actual Experiment(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
In particular I used the payoff table 1,because I can see the whole payoff structure.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
1. I always participated in investment.
The reasons for your decisions on participation:
I judged that the probability that I get a large payoff with participation is larger than the probability with nonparticipation.
(6) How did you choose your investment number when you participated in investment?
When your opponent participated in investment:
I chose a number between 6-9.
When your opponent did not participate in investment:
I chose 0.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
I can get a reasonable payoff safely by setting my investment number around 6-9.

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
2658

My payoff is the largest by choosing 11 because my opponent did notparticipate in investment.

273

274

ID Number = 19, Female, Earnings = 2832 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment

Invest. Num.
Practice 3

You
O
¯

Your
Opponent
O
¯

13

12

5740

I chose a safe number at the first time. I expected my opponent to choose
a middle number safely.

You

Your
OpponentO¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You

Participation
in investmentO¯

Invest. Num.

4

Practice 4

Participation
in investment

Invest. Num.

You

Payoff
Table

8

6

8

6

7

The Reason for Your Decision on Participation

I felt that it is wrong to make a profit easily. I understood that one would
prevent his/her opponent from getting a payoff that is larger thanhis/her own payoff.
Your Payoff The Reason for Your Decision on Investment Number
743

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

Because I would like to know whether or not my opponent chooses
around 13 if I do not participate in investment. My opponent would
choose participation at this stage.
Your Payoff The Reason for Your Decision on Investment Number

Your
Opponent
´
¯

O
¯

7

Your Payoff The Reason for Your Decision on Investment Number

854

Your
OpponentO¯

The Reason for Your Decision on Participation
Because my opponent would not choose a large investment number if I
do no participate in investment/

4

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.

Payoff
Table

PayoffTable

I do not like that my opponent gets a payoff that is larger than mine.
However, because I do not like that my payoff is too small, either, I chose
4 so that the difference between my payoff and my opponent's is small.
The Reason for Your Decision on Participation

If my opponent does not choose a large investment number when I do notparticipate in investment, I have to get a large payoff although my
opponent also gets a large payoff.
Your Payoff The Reason for Your Decision on Investment Number

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

7

3405

I chose a number so that my payoff is large if my opponent chooses
around 13 safely.

Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

PayoffTable

The Reason for Your Decision on Participation

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
Because I guessed that my opponent would feel inclined to participate ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
5766

I chose the number that maximizes my payoff if my opponent chooses
around 7. I did not care about my opponent's payoff.

PayoffTable

The Reason for Your Decision on Participation
Because I feel that the participant would not want to give his/her
opponent a large payoff.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because my opponent would choose around 6-8. I chose 8 to make mypayoff large, and I did not care about my opponent's payoff.

PayoffTable

The Reason for Your Decision on Participation
I wanted to go on the gamble. If my opponent considers his/her own
payoff important, he/she will invest a large amount.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I felt a little guilty. The success will not continue and someone mightchoose non-participation.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because 8 is the most effective number when both choose investment
numbers.

PayoffTable

The Reason for Your Decision on Participation
If I do not participate in investment, then the payoff I can get is at most
8278. Therefore, I would like to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number

I cannot expect a high payoff when I choose non-participation. I expectedthat my opponent would not choose a large investment number. My
opponent would also have the same expectation.
Your Payoff The Reason for Your Decision on Investment Number
7340

Payoff
Table

Because my opponent would invest around 6-10 and I chose 7 that leads
to the highest payoff for such a number.
The Reason for Your Decision on Participation
To get a reasonable payoff safely. Perhaps, I may get at least 2000 byparticipation.

Your Payoff The Reason for Your Decision on Investment Number6339

I expected my opponent to choose around 7 because I chose 7 at the lastperiod. Therefore, I chose 6. Choosing 8 gives my opponent anadvantage.

275

8

6

Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

8

6

5766

I chose 8 that lead to a large payoff because my opponent would choose
6-8.

PayoffTable

The Reason for Your Decision on Participation
There seems to be only two choices: "non-participation" or "investing 8".
This is dull. I went on the gamble. I can get at most 7345 by investing 8.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because the others would also get reasonable payoffs safely and mightfeel that they do not like to make their opponents large.

Your Payoff The Reason for Your Decision on Investment Number
5766

Because of my failure at the last period. I chose 8 again to get a safe
payoff.

276

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

88Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

10

Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

86Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯

Invest. Num.
87Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
88Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.

8

PayoffTable

The Reason for Your Decision on Participation
I expected that I would be able to get at least 5000 by participation. I got
less than 2000 by non-participation several periods ago.

Your Payoff The Reason for Your Decision on Investment Number
7345

I cannot imagine any number other than 8 so as to get a reasonable payoffsafely.

PayoffTable

The Reason for Your Decision on Participation
Because the others seem to have the same idea as mine.

Your Payoff The Reason for Your Decision on Investment Number
2615

I chose a large investment number because I did not like to decrease mypayoff. However, because choosing 11 gives my opponent a large payoffthat is hard to get usually, I chose 10. (But I should have chosen 8.)

PayoffTable

The Reason for Your Decision on Participation
Because I do not like to get only 706 when my opponent did notparticipate in investment.

Your Payoff The Reason for Your Decision on Investment Number
5766

I cannot image any other number. Because my opponent would invest at
most 7. So do I.

PayoffTable

The Reason for Your Decision on Participation

I hesitated to go on the gamble because my payoffs were low at the lasttwo periods. If it had happened only once, I might have chosen nonparticipation.
Your Payoff The Reason for Your Decision on Investment Number

ID Number = 19, Female, Earnings = 2832 yen.
(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 3) in Practice(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
I referred to the payoff tables for the case OO because both participated in investment at most periods. I understood thatinvesting too much is wasteful and investing too little is not profitable. It is most effective that my investment number
and the other are similar and appropriate. I referred to both the payoff tables for the case O´ and those for the case ´O
when my opponent did not participate in investment. I was vexed that my opponent got a large payoff when I invested
a large amount.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of my opponent's payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
3. I did not participate in investment several times, but the number of periods at which I participated ininvestment was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
I almost always chose participation so as to get a safe payoff. I did not participate in investment several times, because(i) I wanted to know how my opponent reacts, (ii) I became greedy for the payoff after knowing it, or (iii) I was tired ofchoosing participation.

6526

Choosing this number would be the best for both my opponent and me.

(6) How did you choose your investment number when you participated in investment?

PayoffTable

The Reason for Your Decision on Participation

When your opponent participated in investment:

To get a reasonable payoff safely.

I expected my opponent's investment number, and then I chose a number so that I received the highest payoff for that
expected number.

Your Payoff The Reason for Your Decision on Investment Number
7345

My payoff is more important than my opponent's is. Please choose 8.

PayoffTable

The Reason for Your Decision on Participation
I chose participation again, because I was afraid that my opponent mightchoose non-participation.

Your Payoff The Reason for Your Decision on Investment Number
2386

There is little difference between 2638 and 2386, and it is not interestingthat my opponent also gets 4904.

277

When your opponent did not participate in investment:
My payoffs are not very different, but I did not like that my payoff was too low. I did not like that my opponent got alarge payoff, either. I chose a number so that my payoff is similar to the one I got usually when I participated ininvestment.
(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?
I almost always chose 8 and that would be the best. By looking at the payoff tables, I think that investing a number
between 6 and 8 would be appropriate. I can get the highest payoff by choosing 8 if my opponent chooses 6-8. If it isdifficult to see the behavior of the opponent, then participate in investment to see how he/she reacts and invest 8. Thisis the most effective for both my opponent and me.

278

ID Number = 20, Male, Earnings = 2859 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

You
O
¯

Your
Opponent
O
¯

6

4

2181

For no particular reason.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13
You

To see what happens.
Your Payoff The Reason for Your Decision on Investment Number

I chose investment for the time being.
Your Payoff The Reason for Your Decision on Investment Number
1631

To get the highest payoff.

PayoffTable

The Reason for Your Decision on Participation

O
¯
13

10

4809

Choosing this number is most effective even if my opponent invests 0. It
is better if he/she invest at least 1.

You

Your
Opponent´¯

PayoffTable

The Reason for Your Decision on ParticipationO¯

Invest. Num.

13

Period 1 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment
¯
¯
6

6

Period 2 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation

Your
OpponentO¯Participation
in investment

Invest. Num.

PayoffTable

6

9

I chose investment for the time being.
interesting as a game.

"Non-participation" is not

Your Payoff The Reason for Your Decision on Investment Number"Participation" is meaningful. It is good if everyone thinks so.
Your Payoff The Reason for Your Decision on Investment Number
1631

To get the highest payoff.

PayoffTable

The Reason for Your Decision on Participation
Because "participation" is interesting.

Your Payoff The Reason for Your Decision on Investment Number
5515

I expected my opponent to choose at most 11. Choosing 6 maximizes mypayoff when he/she chooses 11.

PayoffTable

The Reason for Your Decision on Participation
Everyone seems to expect the other to participate in investment. I will
come up to that expectation. Do all participate in investment?

Your Payoff The Reason for Your Decision on Investment Number
8209

The same as the above.

Period 3 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 4 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
65
Period 5 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 6 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

7

Period 7 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 8 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
6
1
Period 9 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

279

6

6

7

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4762

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2658

I invested 11 so as to maximize my payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

I expected my opponent to choose at most 11. Choosing 6 maximizes mypayoff when he/she chooses 11.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

The same as the above. I wanted to avoid that both of us will come togrief (´´).
Your Payoff The Reason for Your Decision on Investment Number
2427

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as the above.

280

Period 10 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
6
10Period 11 of the Actual Experiment
You
Your
Opponent
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 12 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

67

Period 13 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 14 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.
68Period 15 of the Actual Experiment
You
Your
Opponent
ParticipationOO
in investment¯¯
Invest. Num.

6

4

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
9257

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2658

I invested 11 so as to maximize my payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

I expected my opponent to choose at most 11. Choosing 6 maximizes mypayoff when he/she chooses 11.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 20, Male, Earnings = 2859 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you
decided your investment number?
The payoff table 1. In the payoff table for the actual experiment, when my opponent chooses 0, the investment number
to maximize my payoff is 11 (not 24). As the investment number of my opponent increases, the investment number tomaximize my payoff decreases. Therefore, investing more than or equal to 12 is less profitable than investing less thanor equal to 11. Investing less than or equal to 11 is reasonable.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of
thinking on participation and investment decisions?
3. It is desirable that both my payoff and my opponent's payoff are as high as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate ininvestment?
1. I always participated in investment.
The reasons for your decisions on participation:
Because I wanted to avoid that both of us will come to grief (´´). Because I supposed that a half of people would choose´, I could not adopt the strategy that "do not participate in investment at all periods."

7237

The same as the above.

(6) How did you choose your investment number when you participated in investment?

PayoffTable

The Reason for Your Decision on Participation

When your opponent participated in investment:

The same as the above.

Although my opponent's investment number was unknown, I expected it to be less than or equal to 11 because he/shewould expect my investment number to be 0. I decided to choose my investment number to maximize my payoff whenmy opponent's investment number is the maximum (11).

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

When your opponent did not participate in investment:

PayoffTable

The Reason for Your Decision on Participation

I chose the number to maximize my payoff.

The same as the above.

(7) Finally, what would be the best choice for your participation and investment? What do you think from yourexperience in the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
4078

The same as the above.

281

My opponents did not participate in investment only twice out of 15 periods in the actual experiment. If I had expected
this, I would have chosen the advantageous strategy (the free-rider strategy) that non-participation in investment at all
periods. Because my opponent would choose 11 to maximize his/her payoff when I do not participate in investment,
but my opponent does, I could get a rather large payoff surely.

282

6. Data for the Tokyo B' Session (without the "Opponent" Wording)
6.1. Pairs of Subjects (ID Numbers) in the Tokyo B' Session: the Same as the Tsukuba A Session (see Table 3.1.)
6.2. Participation Decisions of Each Subject in the Tokyo B' Session: 1 = Participate, O = Not Participate.
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1

2

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

3

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

4

1
1
1
1
1
1
1
1
1
1
0
1
1
1
1

5

1
0
1
1
1
0
0
0
0
0
1
1
1
0
1

6

0
1
1
0
1
0
1
0
0
0
1
1
1
1
1

7

0
1
1
0
1
1
1
0
0
0
1
0
1
0
0

8

0
1
1
0
1
1
1
1
1
1
1
1
1
1
1

9

0
0
1
1
1
1
1
1
1
1
0
1
1
1
1

1
1
1
1
1
1
1
1
1
1
1
1
1
1
1

10 11 12 13 14 15 16 17 18 19 20
1
1
1
1
1
1
0
1
0
1
0
1
1
0
1
1
1
0
1
1
1
1
0
1
0
1
1
1
0
1
1
1
0
1
0
0
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
0
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
0
0
1
1
1
1
1
1
0
0
1
0
0
1
1
1
1
1
0
1
1
1
0
1
1
1
1
1
1
1
1
0
1
0
1
1
1
1
1
1
1
0
1
1
1
0
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1

6.3. Participation Decisions of the Persons Each Subject was Paired with in the Tokyo B' Session: 1 = Participate,
O = Not Participate.
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1

2

0
1
0
1
1
1
0
1
1
1
1
1
1
1
1

3

1
0
1
1
1
0
1
1
1
1
1
1
1
1
0

4

1
1
1
1
1
1
1
1
1
0
1
0
1
1
1

5

0
1
0
1
1
0
0
1
1
0
0
1
1
1
1

6

0
1
1
1
1
1
1
1
1
1
1
0
1
1
1

7

1
0
1
1
1
1
1
1
1
1
1
1
1
1
1

8

0
1
1
1
1
1
1
1
0
1
1
1
1
0
1

9

1
1
0
1
1
1
1
1
0
1
1
1
0
1
1

1
1
1
0
1
1
1
1
1
0
1
1
1
1
1

10 11 12 13 14 15 16 17 18 19 20
1
0
1
0
1
0
1
1
1
1
1
1
1
1
0
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
0
0
1
1
1
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
1
0
0
0
1
1
1
1
1
1
0
1
1
1
1
1
0
0
0
1
1
0
0
1
1
1
1
1
1
1
0
0
1
1
0
1
1
1
0
1
0
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
1
1
1
0
1
0
1
1
1
1
1
1
1
1
1
1
0
1
1
1
1
1

283

6.4. Investment Numbers of Each Subject in the Tokyo B' Session (blank means non-participation).
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1
11
8
0
11
8
8
9
8
7
7
7
10
7
8
8

2

3
6 12
5 8
8 8
9 8
6 8
4 8
7 8
8 8
8 8
9 1
8
8 4
8 8
8 8
8 8

4

2

5

2
2
3

6

7

8
8

11
10

8
7

8

12
7
7

8

4
8
3
0

8
6
10
8
8

6
5
6
6
11
5
7 6
4
7 4
11
6

8

9

11
0
6
9
7
8
11
6
8
3
8
9

7
7
7
7
7
7
8
8
8
6
8
8
8
8
8

10 11 12 13 14 15 16 17 18 19 20
0 11
7
0
9 11
12
8
24 14
0
9 6
6
8 7
8
12
0
9 6
9
8 6
15
3 11 6
11
3 6
7
0
9
8
6
9 6
7 7
8 7
8
6 11
6
6
7 11
8 8
8
1
3
6
9 7
7 9
8 8
12
8 11
3
9 7
7 9
8 6
8
24
6
6
6 7
3 9
8
0
6
7 9
8 6
7
13 11
6
7
6 9
3 3
8
12 11
6
7
7 9
8 7
8
12
11
6 10
7 7
8 7
8
8
6
3
9 11
7 7
8 8
8
12
9
6 11 117 78 8
86.5. Investment Numbers of the Persons Each Subject was Paired with in the Tokyo B' Session (blank means non-participation).
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1

2
0
8
8
7
9
8
6
9
6
8
8
8
0

8
2
9
8
7
8
6
8
7
7
7

3
7
8
9
11
0
6
7
7
9

4

5

11
9
7

9
3

4
8
7
8

6
7
11
8

8
6
7
6
11
8
3
7
0
8
8
9
8

6
7
11
8
9 0
6 3
6 12
6 7
8 9
11 8
6
6 6
8 3
11 12
7 7
3
8 8

8
2
5
11
8
8
7
12
5
3
8
6
8

9 10 11 12 13 14 15 16 17 18 19 20
12 6
8
12
11 9
0 7 11
8 7
8
6
6 9
0
14 24
7
12 0
7 11
7 10 8
2 8
8
6
6 11
3
15
7 0
3 8
6
8
7
8 7
8 6
9 6
8
5 7
8
4 8
8 8 11 7
6
7 9
6
9
3
1 8
7 6
7 8
8 8
6
8
8 8
6 8
9
6
7 24
8 11 11
8
8
1
9
7 6
8 7
7
9 6
7
7 11 13
8
6
7
8 4
6
8
4 8
8 7 10 97
10 6 11128 3
4 7 10 3
8
8 8
8 11
8
8 8
8 8
8
8 7
7 11 11
6
9 12
8 9
6

284

6.6. Pairs of Investment Numbers in the Tokyo B' Session (blank means non-participation and boldfaced numbers indicate data ofsubjects who did spiteful behavior).
Period 1
ID # Invest. #1,6 112,10
6
0
3,9 127
2
4,85,7
11,20 11
12,19
7
8
0
13,18
14,17
9 12
15,16 11Period 2
Period 3
Period 4
Period 5
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #
0
1,5
8
8
1,10
1,3 11
8 1,16
8
7
5
2,8
2,18
8
8
2,4
9
2 2,11
6
9
7 3,10
3,7
8
8
3,17
8
9 5,20
8
0
2
6
4,6
11
4,16
6,19
4,9
3
7
3
9,20
7
8
5,15
8
6 7,185,8
8
6
10,19 24
7
6,14 10
9 8,170 11
6,7 12
6
7
11,18 14
8
7,13
7
0 9,16
12,20
8
8
6
12,17
8,12 11
10,15 15
6 13,19
6
7
0
13,16
9,11
7 12 11,14
11 14,18
98
6
3 15,1714,15
9
6 19,2012,13
6
7

Period 9
ID # Invest. #
1,11
7
6
2,20
8
8
3,19
8
9
3
4,18
7
5,17
6
6,16
7,15 11
8,14 119,13
8
6
10,12 24

Period 10
ID # Invest. #
1,17
7
9
2,13
9
6
1
3,12
4,11
0
5,10
6
6,9
7,8
5
6
7
14,20
6
15,19
16,18
7
8

Period 6
Period 7
Period 8
ID # Invest. # ID # Invest. # ID # Invest. #91,8
8
9 1,12
1,9
8
8
4
2,14
2,3
7
8 2,168
73,13
8
6 4,20
3,15
8
7
4,12
5,19
8
8 4,149
3
5,11
11 6,187
8 5,13
6,10
7
6 7,176
9 6,12
11
7,9
5
7 8,167
7 7,11
6
815,20
6
8 9,158
7 8,108 1216,19
7
8 10,141
9 17,2098
17,18 11
8 11,133
6 18,198
6

Period 11
Period 12
Period 13
Period 14
Period 15
ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. # ID # Invest. #1,13
7
6 1,18 10
81,2
7
8 1,19
8
8
1,4
8
0
8
2,5
8
8 2,158
7 3,208
8 2,178
72,6
4 3,144
3,4
4,19
3
7 3,16
8
7
3,5
8
8
6,20
7
8 4,138
6 5,18 10
8 4,15
11 7,20
6
8
6
7,19
6
3 5,12
6,17
7
7 5,148
9 8,199
8
3 6,11
3 9,188,18
11 7,164
7 6,1388
3
9,17
8
9 7,104 12 8,15
7,12 11
10,17 12
7
6
10,16
8,9
8
8 9,148 10 8,11
8
6 11,169
7
11,15 13
7 16,207
8 10,13 12
6 9,108
8 12,15
11
12,14 1117,19
9
7 11,12
11 18,20
8
8 13,146 11285

6.7. Payoffs of Each Subject in the Tokyo B' Session
ID #Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Period 8
Period 9
Period 10
Period 11
Period 12
Period 13
Period 14
Period 15

1
2658
7345
706
6765
6526
8225
2523
7345
5681
8271
5681
7056
7340
7345
2386

2
3
2003 5800
1775 7345
7345 8225
3411 10173
8209 2386
1536 5766
7340 6526
6526 6526
7345 8225
5765
871
7345 20176526 1536
6526 7345
6526 6526
2386 7345

4
1072
8278
1072
6984
5440
706
706
5907
1554
706
1536
5766
5440
8278
4904

5
706
7345
5766
4018
5766
8278
7345
1554
4018
706
7345
2003
7056
8225
7345

6
7
8
9
8278
706 1186 11480
2658 7345 2578 7340
7816 2210 2658 11480
3244 1554 8278 2210
5249 11589 7237 3675
5681 6115 7250 4950
7340 8209 6478 6526
8278 7237 11242 7345
3244 2658 2658 5766
3244 5272 4762 2003
7340 3463 1554 8225
8278 11416 7345 7345
6478 5812 1297 9168
1554 2658 5766 7345
4904 7237 7250 7345

10
3244
500
706
4065
4904
6339
6475
6385
500
706
3244
4250
5249
7345
5800

11
12
13
14
15
2658 7340
706 10877 2658
5393 3244
706 5765 8209
5800 8278 4018 8951 7237
8278 1554 1297 2658 15694
5765 7345 6339 7250 6339
2658
706 7237 2017 7237
4590 5907 3463 2944 7340
5766 2658 1297 2523 7340
6339 37111 7237 8278 8278
706
905 8209 4018 3244
5406 2658 6339 8278 12694
2658 3244 7237 2017 7340
8278 2658 11589 7056 1554
7237 8278 1297 7250 2658
6481 8278 10384 5504 2658

286

16
17
18
19
8278 7007
706 6526
706 2003 13576 31155
1186 7250 7345 2003
4018 2658 1297 2003
7340 5681 8225 5681
7340 6765 10173 6526
6478 5765 6526 7345
7340 7250 5766 7237
2003 2210 1297 7250
7340 6481 6526 2003
2003 7250 1297 4590
7340 6481 9168 8271
4281 6478 9168 3675
7340 7340 7345 7345
8271 11480 7345 8225

20
8278
6526
3244
2210
7345
5766
706
8225
7345
2210
6526
6526
7345
7345
5766

6.8. Record Sheets and Questionnaires for the Tokyo B’ Session
ID Number = 1, Female, Earnings = 2833 yen.
Practice 1

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.
Practice 2

12

8

4381

My payoff I can get is not bad even if the other person chooses 0.

You

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment
Invest. Num.
Practice 3

You

´
¯

The Reason for Your Decision on Participation
To see what happens by choosing participation.

Your Payoff The Reason for Your Decision on Investment Number

To see what happens by choosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number

13

6117
PayoffTable

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.
Practice 4

10

9

5019

Because the other person seems to be timid.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

You

PayoffTable´¯

Invest. Num.

Because my payoff would be larger by participation than by nonparticipation.
Your Payoff The Reason for Your Decision on Investment Number

To see what happens by non-participation once more.
Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation

8

8

PayoffTable

The Reason for Your Decision on Participation
Because I can avoid the case ´´ by participation.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because I want to get the highest payoff.

PayoffTable

The Reason for Your Decision on Participation
Because I feel that participating in investment is not unfair to both theother person and me.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I think that the other person chose 8 in practice.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 4 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

8

Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
89Period 7 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

9

Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 9 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

287

11

7

6

PayoffTable

The Reason for Your Decision on Participation
Because participation seems not to suffer a loss.

Your Payoff The Reason for Your Decision on Investment Number
706

Because I was a little mad.

PayoffTable

The Reason for Your Decision on Participation
To give the other person a favorable impression on me.

Your Payoff The Reason for Your Decision on Investment Number
6765

It is silly to choose a large number. But I would like to give the otherperson a reasonable payoff.

PayoffTable

The Reason for Your Decision on Participation
To give the other person a favorable impression on me.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because many persons have chosen 8.

PayoffTable

The Reason for Your Decision on Participation
Because I expected the other person not to choose ´.

Your Payoff The Reason for Your Decision on Investment Number
8225

Because I expected the other person to choose around 7-10.

PayoffTable

The Reason for Your Decision on Participation
Because I expected to get a higher payoff by choosing participation.

Your Payoff The Reason for Your Decision on Investment Number
2523

I chose a number so that the payoff of the other person is not large andmy payoff is not small.

PayoffTable

The Reason for Your Decision on Participation
To increase choices available to me.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because the other seems to be a good person.

PayoffTable

The Reason for Your Decision on Participation
To give the other person a favorable impression on me.

Your Payoff The Reason for Your Decision on Investment Number
5681

Because the other seems to be timid.

288

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
79Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
108Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

80

PayoffTable

The Reason for Your Decision on Participation
Because participation would be safe probably.

Your Payoff The Reason for Your Decision on Investment Number
8271

Because I expected the other person to choose 7 or 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

Because I thought that we would finish by breaking even if I chose 7 or 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

ID Number = 1, Female, Earnings = 2833 yen.
(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period (2 ) in Practice(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
By looking at the payoff tables, I felt that if my investment number and the number of the other person is similar, we finish
by breaking even.
I looked at the payoff table 1 when I decided my investment number.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
3. It is desirable that both my payoff and the payoff of the person I am paired with are as high as possible.

Your Payoff The Reason for Your Decision on Investment Number
7056

It was not bad to get at least 5000.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected the other person to choose 8 or 9.

PayoffTable

The Reason for Your Decision on Participation
To give the other a favorable impression on me.

Your Payoff The Reason for Your Decision on Investment Number(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
To give the other a favorable impression on me.
To enlarge available choices.
(6) How did you choose your investment number when you participated in investment?
When the person you are paired with participated in investment:
I judged whether or not the other person was timid by looking at his/her way of writing.
Then I chose a number by using the payoff table.

7345

Because I expected the other person to choose 8 perhaps.

When the person you are paired with did not participate in investment:

PayoffTable

The Reason for Your Decision on Participation

Because I was mad, I wrote 0, too.

To enlarge available choices.

(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
2386

Because I expected the other person to choose 7 or 8.

289

It is good to choose numbers so that we finish by breaking even.
The reason: If one person gains, then the other loses and feels unhappy. It is desirable that everyone feels receiving equal
payoffs.

290

ID Number = 2, Female, Earnings = 2659 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

The
Person ...
O
¯

4

12

6785

To see what happens.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

The
Person ...
O
¯

9

16

10411

Because my number was small.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation´¯

The Reason for Your Decision on Participation
To get used of the experiment.

Your Payoff The Reason for Your Decision on Investment Number

To see what happens once more.
Your Payoff The Reason for Your Decision on Investment Number

To save investment for the last period.
Your Payoff The Reason for Your Decision on Investment Number
500

You
O
¯

The
Person ...
O
¯

11

5

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
60Period 2 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

PayoffTable

5

PayoffTable

The Reason for Your Decision on Participation
Because this is last.

Your Payoff The Reason for Your Decision on Investment Number
3093

PayoffTable

I occasionally invested a large amount.

The Reason for Your Decision on Participation
Because this is first.

Your Payoff The Reason for Your Decision on Investment Number
2003

Because it would be good to invest this amount at the first time.

PayoffTable

The Reason for Your Decision on Participation
Because the result at the first period was unexpected.

Your Payoff The Reason for Your Decision on Investment Number
1775

Because my payoff is similar to the payoff of the other person.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 4 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
92
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
69Period 6 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 9 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

291

8

8

PayoffTable

The Reason for Your Decision on Participation
Because I have not gotten enough payoffs.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected not to incur a large loss by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
Because I got a reasonable payoff finally.

Your Payoff The Reason for Your Decision on Investment Number
3411

Because I expected that both would not incur large losses.

PayoffTable

The Reason for Your Decision on Participation
Because my payoffs were not good.

Your Payoff The Reason for Your Decision on Investment Number
8209

Because I expected that both would not incur large losses.

PayoffTable

The Reason for Your Decision on Participation
Because I got a reasonable payoff at last.

Your Payoff The Reason for Your Decision on Investment Number
1536
Payoff
Table

Because both payoffs were similar.
The Reason for Your Decision on Participation
Because my payoffs were not good.

Your Payoff The Reason for Your Decision on Investment Number
7340

Because I expected that both would not incur large losses.

PayoffTable

The Reason for Your Decision on Participation
Because I got a reasonable payoff at last.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because I expected this to be the average number.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

292

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
96Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

8

PayoffTable

The Reason for Your Decision on Participation
Because I got a reasonable payoff.

Your Payoff The Reason for Your Decision on Investment Number
5765

Because both payoffs were similar.

PayoffTable

The Reason for Your Decision on Participation
Because I got a reasonable payoff.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 2, Female, Earnings = 2659 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I referred to the payoff table 1. I marked the investment numbers that maximize my payoffs, and I chose investment
numbers so that my payoff and the payoff of the other person were similar and they became the highest.

7345

Because I expected this to be the average number.

(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?

PayoffTable

The Reason for Your Decision on Participation

3. It is desirable that both my payoff and the payoff of the person I am paired with are as high as possible.

Because I got a reasonable payoff.
Your Payoff The Reason for Your Decision on Investment Number
6526

Because I expected the other person to choose the same number.

PayoffTable

The Reason for Your Decision on Participation
Because non-participation is not profitable for both the other person andme.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because I expected this to be the average number.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
Because non-participation was not profitable for both the other person and me.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
I chose investment numbers so that my payoff and the payoff of the other person were similar and they became the highest.
When the person you were paired with did not participate in investment:
I chose investment numbers so that my payoff and the payoff of the other person were similar.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Because I do not know who the other person is, it is good that both my payoff and the payoff of the other are similar. If I
consider my own payoff only, then there is the risk that the other person decreases his/her investment number after all.

Because this is last.
Your Payoff The Reason for Your Decision on Investment Number
2386

The same as the above.

293

294

ID Number = 3, Female, Earnings = 2858 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

The
Person ...
O
¯

12

12

6194

Because I expected the other person to invest around 10-12.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

The
Person ...
O
¯

12

8

4213

Because I expected the other person to choose around 12.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

The
Person ...
O
¯

12

7

3792

Because I expected the other person to choose around 12.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on ParticipationO¯
13

Invest. Num.
127Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment
¯
¯
8

8

The Reason for Your Decision on Participation
Because I can get a higher payoff by choosing participation, regardless ofwhether or not the person I am paired with chooses participation.

Your Payoff The Reason for Your Decision on Investment Number

Because participation is more profitable.
Your Payoff The Reason for Your Decision on Investment Number

Because participation is more beneficial.
Your Payoff The Reason for Your Decision on Investment Number

Because participation is more beneficial.
Your Payoff The Reason for Your Decision on Investment Number
1631

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

Invest. Num.

Payoff
Table

PayoffTable

The other person did not participate in investment.

The Reason for Your Decision on Participation
Because I can get a higher payoff by choosing participation, regardless ofwhether or not the other person chooses participation.

Your Payoff The Reason for Your Decision on Investment Number
5800

I expected the investment number of the other person to be 12.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected the other person to invest 7-9.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
89Period 4 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
811Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
80Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
86Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

7

Period 9 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

295

8

8

9

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8225

I expected the investment number of the other person to be 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
10173

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2386

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766
PayoffTable

The same as the above.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected the investment number of the other person to be a number
between 6 and 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8225

The same as the above.

296

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
1
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 12 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

88Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number871

The other person did not participate in investment.

PayoffTable

The Reason for Your Decision on Participation
Because by choosing non-participation I get a high payoff if the otherperson participates in investment and invest a lot of amounts.

Your Payoff The Reason for Your Decision on Investment Number
2017
PayoffTable

The Reason for Your Decision on Participation
Because I would get a larger payoff by participation.

ID Number = 3, Female, Earnings = 2858 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
The situation that both do not participate in investment is the worst. I referred to the payoff table 1. When I only
participated in investment, but the other person did not, I looked at the payoff table 3 to see how my investment affects thepayoff of the other.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
3. It is desirable that both my payoff and the payoff of the person I am paired with are as high as possible.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

Your Payoff The Reason for Your Decision on Investment Number
1536
PayoffTable

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.

The Reason for Your Decision on Participation

The reasons for your decisions on participation:

Because if everyone participates in investment, then my payoff and thepayoff of the other person are similar and reasonably high.

I wish I had participated in investment at all periods, because both could have gotten large payoffs if everyone hadparticipated in investment. However, the other persons did not participate in investment twice, and I did not choose
participation once, because I thought that I would get a large payoff if the other person invests a lot of amounts.
Nevertheless, I realized from the result that participating in investment is good for both the other and me, and thereafter I
had participated in investment at all remaining periods.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected the investment number of the other person to be
between 6 and 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
I chose a number so that my payoff and the person of the other person became similar.

6526

The same as the above.

When the person you were paired with did not participate in investment:

PayoffTable

The Reason for Your Decision on Participation

I chose a number so that the other person did not get a large payoff even though I suffered a loss.

The same as the above.

(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected the investment number of the other person to be 8.

297

It is the best to participate in investment and set the investment number at around 8 in all periods. This is because thepayoffs of participants are equally large.

298

ID Number = 4, Male, Earnings = 1926 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation

7

8

4368

I would like to get at least 1000. Choosing 7 gives the other person at
most 4000.

You

PayoffTable

The Reason for Your Decision on Participation

Because I do not like that my payoff is 500 if the other person alsochooses non-participation.
Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.

9

10

5707

The other person will choose a number between 7 and11 if he/she
realizes that investing a lot of amounts does not lead to a large payoff.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

The
Person ...
O
¯

8

4

2524

By looking at the table carefully, I understand that it is good to invest 213.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation

Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

O¯
6The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
1007

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
2
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

There isn't much to be gained by choosing non-participation. The payoff
I can get by choosing participation and investing 1 is almost the same asthat by choosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number

11

PayoffTable

I checked the payoff of the other person by using the payoff table 3, anddid not let him/her get more than 1508. I want to get at least 1000.

The Reason for Your Decision on Participation

Because it seems to me that I cannot get a high payoff in both the case of ´´ and the case of ´O.
Your Payoff The Reason for Your Decision on Investment Number
1072
Payoff
Table

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
2
Period 4 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
2
9Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

3

7

Period 6 of the Actual Experiment
You
The
Person ...
Participation´´
in investment¯¯
Invest. Num.
Period 7 of the Actual Experiment
You
The
Person ...
Participation´´
in investment¯¯
Invest. Num.
Period 8 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯To get at least 1000. I do not like to let the other person get a high payoff.
The Reason for Your Decision on Participation
I do not know what will happen, but for the time being I try nonparticipation to see what the other person thinks.

Your Payoff The Reason for Your Decision on Investment Number

Invest. Num.
9
Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment
¯
¯

8278
Invest. Num.

299

3

PayoffTable

The Reason for Your Decision on Participation
Because I expected that the same thing would not happen this time.

Your Payoff The Reason for Your Decision on Investment Number1072

The same reason as that at period 1.

PayoffTable

The Reason for Your Decision on Participation
I believed the other person to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
6984

I expected the other person to choose 9-11.

PayoffTable

The Reason for Your Decision on Participation
Everyone seems to get a large payoff.

Your Payoff The Reason for Your Decision on Investment Number
5440

PayoffTable

To make my payoff high and the payoff of the other person low. I
expected the other to choose 9-13.
The Reason for Your Decision on Participation
I expected the other person to choose 11 because he/she would consider
his/her payoff only.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Choosing non-participation would be better although it is risky. If theother person chooses participation, I can get 8278 surely.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I believed the other person to choose participation next time.

Your Payoff The Reason for Your Decision on Investment Number
5907
PayoffTable

The Reason for Your Decision on Participation
I can get a large payoff if the other person chooses participation.

Your Payoff The Reason for Your Decision on Investment Number
1554

300

Period 10 of the Actual Experiment
You
The
Person ...
Participation´´
in investment¯¯
Invest. Num.
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

4

Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
86Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
2
7
Period 14 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

0

8

PayoffTable

The Reason for Your Decision on Participation
I stick to choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I will participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
1536

I consider both my payoff and the payoff of the other person. Investing 4
is not bad.

PayoffTable

The Reason for Your Decision on Participation
I believed the other person to choose participation. Everyone would get alarge payoff.

Your Payoff The Reason for Your Decision on Investment Number
5766
PayoffTable(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
Only the payoff tables A were useful. It is meaningless to invest more than 11. I found that which investment number I
should choose to maximize my payoff for each number of the other person: 11 for 0-1, 10 for 2-3, 9 for 4-5, and 8 for 6-8. I
was surprised that my payoff is always smaller than the payoff of the other.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify). I tried to take behavior that the other person did not expect. When the other person
took behavior as I expected, I attempted to make the payoff of the other low and my payoff high.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.

The Reason for Your Decision on Participation

The reasons for your decisions on participation:

I chose participation to get at least 2658.

I considered how behavior of the other person would change as rounds advanced.

5008

Because I expected the other person to choose 7-10.

PayoffTable

The Reason for Your Decision on Participation
Because I would like to go on the gamble. The other person would
choose around 11.

Your Payoff The Reason for Your Decision on Investment Number(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
I chose an investment number between 2 and 4 to get a larger payoff than the other person does. At early periods, I chose anumber between 6 and 8, but I did not like that the other person obtained a larger payoff than I did.
When the person you were paired with did not participate in investment:
I chose a number so as to make the payoff of the other low. I did not care that my payoff was low.

8278
The Reason for Your Decision on Participation
I will surprise the other person by choosing participation and investing 0.
Your Payoff The Reason for Your Decision on Investment Number
4904(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.

I expected the other person to choose 6-8.

Your Payoff The Reason for Your Decision on Investment Number

PayoffTable

ID Number = 4, Male, Earnings = 1926.

To get a large payoff.

301(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Participate in investment at all periods. Choose 8 if the other person participates in investment, and choose 11 otherwise.
By choosing 8, my payoff is close to the maximum value, regardless of which number the other chooses. I think this is thebest choice.

302

ID Number = 5, Male, Earnings = 2557 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You
´
¯

You
O
¯

The
Person ...
O¯

Your Payoff The Reason for Your Decision on Investment Number
6117

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation
Because the other person may not participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
1631

Because my payoff is maximized.

PayoffTable

The Reason for Your Decision on Participation

O
¯

The
Person ...
O
¯

7

11

6432

Because I expected the other person to invest 13.

You

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation´¯

Invest. Num.

6

Period 1 of the Actual Experiment
You
The
Person ...
Participation´´
in investment¯¯
Invest. Num.
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation
Because I expected the other person to participate in investment.

13

13
You

PayoffTable

8

8

For no particular reason.
Your Payoff The Reason for Your Decision on Investment Number

Because the other person seemed to choose participation.
Your Payoff The Reason for Your Decision on Investment Number
1416

PayoffTable

The Reason for Your Decision on Participation
Because the other person seemed to choose participation.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because I think chances are about even that the other person will
participate in investment.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected the other person to invest a number between 7 and11.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
86Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
86Period 6 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 8 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
3
Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

303

7

PayoffTable

The Reason for Your Decision on Participation
Because the case ´´ is worse than the case O´.

Your Payoff The Reason for Your Decision on Investment Number
5766

Because I expected the other person to invest 8.

PayoffTable

The Reason for Your Decision on Participation
Because I expected the other person to choose O.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation
Because the other person seemed to be spiteful.

Your Payoff The Reason for Your Decision on Investment Number
5766

Because I expected the other to invest 7.

PayoffTable

The Reason for Your Decision on Participation
Because it is better to choose ´ more often.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
Because it is not necessarily true that I get 8000 in the case ´O.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I think that investing 8 is the best choice.

PayoffTable

The Reason for Your Decision on Participation
Because I would like to choose ´ more often.

Your Payoff The Reason for Your Decision on Investment Number
1554
PayoffTable

The Reason for Your Decision on Participation
Because it would be better to choose ´ more often.

Your Payoff The Reason for Your Decision on Investment Number
4018

304

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 12 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

6

Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
108Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
89Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation
I would like to get 8000.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because the other person seems to be spiteful.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I think investing 8 is the best choice.

PayoffTable

The Reason for Your Decision on Participation
Because I expected the other person to choose non-participation at lateperiods.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 5, Male, Earnings = 2557 yen.
(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 1 ) in Practice ž Actual Experiment(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I looked only at the upper-left part in the first page of the payoff table 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
My behavior might affect behavior of all others because the number of persons in the experiment is not large. Therefore, I
sometimes took behavior so that the payoff of the other became high a little. But I almost always cared only about mypayoff.

2003

I chose a smaller number so that the other person will not choose ´.

(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

PayoffTable

The Reason for Your Decision on Participation

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.

Because I cannot get a large payoff by choosing non-participation.

The reasons for your decisions on participation:

Your Payoff The Reason for Your Decision on Investment Number
7056

Because the investment number of the other person seems to be small.

PayoffTable

The Reason for Your Decision on Participation
Because choosing participation is steady.

Your Payoff The Reason for Your Decision on Investment Number

At early periods I often chose non-participation because I thought the other persons would consider their own payoffs only.
However, most persons did not consider their own payoffs most important. Because I realized this, I chose participation atlater periods.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:

8225

I decide to choose 8 in the case OO.

When the other person chooses 8, choosing 8 maximizes my payoff. I thought the other person would care only about
his/her own payoff when both choose participation.

PayoffTable

The Reason for Your Decision on Participation

When the person you were paired with did not participate in investment:

Because the result at the last period was good.
Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected the other person to choose 8.

305

I chose the number so that my payoff is maximized.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Participate in investment at all periods. Choose 8 if the other person participates in investment, and choose 11 otherwise.

306

ID Number = 6, Male, Earnings = 2758 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

The
Person ...
´
¯

13
You

PayoffTable

The Reason for Your Decision on Participation
I want to try participation to see what happens at a practice period.

Your Payoff The Reason for Your Decision on Investment Number
1631

Because the other person invested 0.

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.
Practice 3

11

8

4381

Because I expected the other person to choose a large number.

You

PayoffTable

The Reason for Your Decision on Participation

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

109Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.
Practice 4

3

7

2807

Because I can get a large payoff.

Invest. Num.

You

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation

Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯Participation
in investment´¯

Invest. Num.

13

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

11

Because the other person would feel boring if I do not participate ininvestment.
Your Payoff The Reason for Your Decision on Investment Number

I want to try non-participation to see what happens at a practice period.
Your Payoff The Reason for Your Decision on Investment Number
6117

PayoffTable

Invest. Num.
The Reason for Your Decision on Participation
Because the probability that my payoff is 706 is 1/25, while theprobability that my payoff is 8278 is 24/25.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation

Because I would like to avoid the situation ´´ in which neither
participates in investment.
Your Payoff The Reason for Your Decision on Investment Number
2658

Because the other person chose ´.

7

6

6

Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 8 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

307

12

6

PayoffTable

The Reason for Your Decision on Participation

Because I would like to avoid the situation ´´. I want to get a larger
payoff.
Your Payoff The Reason for Your Decision on Investment Number
7816

PayoffTable

The other person chose 0. The other can get a large payoff if his or her
investment number is small and my investment number is large. The
other would choose a relatively small number.
The Reason for Your Decision on Participation
Because the probability that my payoff is 706 is 1/25, while theprobability that my payoff is 8278 is 24/25.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation
Because I want to avoid the situation ´´.

Your Payoff The Reason for Your Decision on Investment Number
5249

Because the probability that my payoff is greater than or equal to 8278 islarge.

PayoffTable

The Reason for Your Decision on Participation
To get a payoff that is greater than or equal to 8278.

Your Payoff The Reason for Your Decision on Investment Number
5681

Because the probability that my payoff is greater than or equal to 8278 islarge. My payoff would be large.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
Because the numbers the other persons chose have been less than 10.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
Because the probability that my payoff is large is higher by choosing nonparticipation.

Your Payoff The Reason for Your Decision on Investment Number
3244

308

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

78

Period 12 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

7

7

Period 14 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
3
Period 15 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

8

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation

Because at three periods the other persons did not invest 11 when I did
not participate in investment. I would like to avoid the situation ´´.
Your Payoff The Reason for Your Decision on Investment Number
7340

Because the probability that my payoff is greater than or equal to 8278 islarge.

PayoffTable

The Reason for Your Decision on Participation
Because the probability that my payoff is large is higher by choosing nonparticipation.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 2 ) in Practice.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I used the red payoff table (payoff table 1) only. I drew lines in the payoff table to distinguish the region in which my
payoffs are at least 10,000, the region in which my payoffs are at least 20,000, and so on. I considered which investment
number I should choose to get a payoff that is larger than some amount. But because the other persons seemed not toconsider their own payoffs most important, or we might make mistakes in writing numbers, things did not go just as I
wanted. I thought there might be some mistakes in the payoff tables of the other persons.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of the payoff of the person I am paired with.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

The Reason for Your Decision on Participation

4. I participated in investment several times, but the number of periods at which I did not participate in investment
was greater than the number of periods at which I did.

I would like to avoid the situation ´´.

The reasons for your decisions on participation:

Your Payoff The Reason for Your Decision on Investment Number
6478

Because the probability that my payoff is greater than or equal to 8278 islarge.

PayoffTable

The Reason for Your Decision on Participation
Because the probability that my payoff is large is higher by choosing nonparticipation.

Your Payoff The Reason for Your Decision on Investment Number

Because I expected that when I did not participate in investment, the probability that my payoff is 706 is 1/25, while theprobability that my payoff is 8278 is 24/25(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
7. I wanted to get at least 8278 when I participated in investment. Therefore, the probability that my payoff is at least 8278
becomes large when I choose a number between 3 and 10. Among them, choosing 7 leads to the largest payoff.
When the person you were paired with did not participate in investment:

1554
PayoffTable

ID Number = 6, Male, Earnings = 2758 yen.

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4904

11. Because my payoff is maximized.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
I thought that the other person would consider increasing his/her own payoff to be most important, as I did. That waswrong.

309

310

ID Number = 7, Male, Earnings = 2755yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

The
Person ...
O
¯

8

7

3195

Because this is a proper number.

You

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You
O
¯
9

You
O
¯
5

Because I wanted to know what happens by choosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number

The
Person ...
O¯

Payoff
Table

The
Person ...
O¯
11Invest. Num.
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
8Your Payoff The Reason for Your Decision on Investment Number

6117

10

8

The Reason for Your Decision on Participation
To get used to the experiment and to see what the other person will do.

13

Period 1 of the Actual Experiment
You
The
Person ...
Participation´´
in investment¯¯

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation
Because of my failure at the last period.

Your Payoff The Reason for Your Decision on Investment Number
5707

PayoffTable

To get the average payoff safely. (I hope the other person to invest alarge investment number. If so, then I can choose a small number).
The Reason for Your Decision on Participation
Because I wished the case O´ would happen.

Your Payoff The Reason for Your Decision on Investment Number
6156

Payoff
Table

Because this is the last period, the other person might choose a large
investment number.

The Reason for Your Decision on Participation
Because I want to see whether or not my expectation on the case inwhich only the other person chooses an investment number is accurate.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
To get a bit of money.

Your Payoff The Reason for Your Decision on Investment Number
7345

To get the average payoff safely.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
70Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

612Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
5
7
Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
69Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

68Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

311

3

11

PayoffTable

The Reason for Your Decision on Participation
To avoid the worst case ´´.

Your Payoff The Reason for Your Decision on Investment Number
2210

I expected the other person to choose a safe number.

PayoffTable

The Reason for Your Decision on Participation
I wanted to do a different thing.

Your Payoff The Reason for Your Decision on Investment Number
1554

I could get a large payoff if the other person wants to save a nice bit ofmoney.

PayoffTable

The Reason for Your Decision on Participation
By intuition.

Your Payoff The Reason for Your Decision on Investment Number
11589

I optimistically expect to the other person to choose a large investment
number.

PayoffTable

The Reason for Your Decision on Participation
I hope the same thing to happen again.

Your Payoff The Reason for Your Decision on Investment Number
6115

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
Choosing participation is not bad.

Your Payoff The Reason for Your Decision on Investment Number
8209

Perhaps the other person would choose a large number.

PayoffTable

The Reason for Your Decision on Participation
Participate is a precondition for making a profit.

Your Payoff The Reason for Your Decision on Investment Number
7237

This is the turning point. The other person would choose a smaller
number (6 or 7).

PayoffTable

The Reason for Your Decision on Participation
To make a profit.

Your Payoff The Reason for Your Decision on Investment Number
2658

My payoff is most important in this case. It is not significant to increase
the payoff of the other.

312

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
5
6
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
63
Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
412Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
47
Period 14 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

6

8

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5272

The other person might choose a smaller number.

PayoffTable

The Reason for Your Decision on Participation
My goal is to get 3,000 yen. To achieve this goal.

Your Payoff The Reason for Your Decision on Investment Number
3463

The other person would choose a smaller number.

PayoffTable

The Reason for Your Decision on Participation
Because I wanted to avoid both the case ´´ and the case ´O.

ID Number = 7, Male, Earnings = 2755 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I referred to the payoff table 1. Because I found that choosing non-participation was very risky in the middle of theexperiment, and afterwards I decided to choose participation.
It may be more efficient to participation and invest 0.
It is easy to get a high point by choosing participation.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of the payoff of the person I am paired with.

Your Payoff The Reason for Your Decision on Investment Number
11416

I expected the other person to choose a small number.

(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

PayoffTable

The Reason for Your Decision on Participation

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.

Because participation is a precondition for making a profit.

The reasons for your decisions on participation:

Your Payoff The Reason for Your Decision on Investment Number
5812

Three periods to go. I would like to score my points safely.

PayoffTable

The Reason for Your Decision on Participation
Because the probability that I make a profit is higher by participation.

Your Payoff The Reason for Your Decision on Investment Number

Because I thought there would be persons who hope the case (´, O) happens by choosing non-participation so as to increase
their points.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
I invested a number between 5 and 7 in an attempt to get at least 5,000 safely.

2658

It is important to score my points in this case.

When the person you were paired with did not participate in investment:

PayoffTable

The Reason for Your Decision on Participation

I invested the number that maximizes my payoff (2,658) in that case.

I wish my total points would reach 30,000 points by choosing
participation.

(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
7237

I expected the other person to choose 6.

313

It would be the best choice to participate in investment at every period and choose an investment number so as to get the
average payoff safely rather than seek a large payoff, because it is fine that the sum of payoffs are large.

314

ID Number = 8, Male, Earnings = 2559 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation

12

12

6194

I chose a number so that I can get a reasonable payoff, regardless ofwhich number the other person chooses.

You

PayoffTable

The Reason for Your Decision on Participation

To see what will happen.
Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.
Practice 3

0

0

500

You

Payoff
Table

Because participation would be beneficial.
Your Payoff The Reason for Your Decision on Investment Number

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.
Practice 4

7

3

1667

Because I could get a better payoff.

You

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment
Invest. Num.

´
¯

24

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
2
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

5

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number

Because I expected my opponent to choose 13.
Your Payoff The Reason for Your Decision on Investment Number
24157

PayoffTable

The Reason for Your Decision on Participation
A single-bout match.

Your Payoff The Reason for Your Decision on Investment Number
1186
PayoffTable

The Reason for Your Decision on Participation
Because I expected the other person to invest 11.

Your Payoff The Reason for Your Decision on Investment Number
2578

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 4 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
011
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
68Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
98Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
7
7
Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
812Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

315

11

PayoffTable

The Reason for Your Decision on Participation
To see what will happen.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because I can the highest payoff.

PayoffTable

The Reason for Your Decision on Participation
To see what will happen.

Your Payoff The Reason for Your Decision on Investment Number
8278

To get a large payoff.

PayoffTable

The Reason for Your Decision on Participation
The probability that I can get a reasonable payoff safely is large.

Your Payoff The Reason for Your Decision on Investment Number
7237

Because I hoped the other person to invest 11.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7250
PayoffTable

To get at least 5,000.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

Because the other person would attempt to get around 7,000-8,000.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
11242

To get at least 5,000.

PayoffTable

The Reason for Your Decision on Participation
To seek 6,000-7,000.

Your Payoff The Reason for Your Decision on Investment Number
2658

To get the highest payoff in this case.

316

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
65
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
3
Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
3
Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
86Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

98

PayoffTable

The Reason for Your Decision on Participation
To make a profit safely.

Your Payoff The Reason for Your Decision on Investment Number
4762

To get at least 5,000 surely.

PayoffTable

The Reason for Your Decision on Participation
To see what will happen.

Your Payoff The Reason for Your Decision on Investment Number
1554
PayoffTable

The Reason for Your Decision on Participation

ID Number = 8, Male, Earnings = 2559 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I almost always use the red table. I thought that getting around 5,000 surely is better than going on a gamble in an attempt
to get a large payoff.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of the payoff of the person I am paired with.

Because choosing participation is safe.

(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

Your Payoff The Reason for Your Decision on Investment Number

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.

7345

To get at least 5,000 surely.

PayoffTable

The Reason for Your Decision on Participation
Because choosing participation is safe.

Your Payoff The Reason for Your Decision on Investment Number
1297

Malice.

PayoffTable

The Reason for Your Decision on Participation

The reason why I did not participate in investment at the first two periods is that I expected the other person to choose 11.
The reason why I participated in investment is that I could gain 5,000-8,000 points by investing 6-8.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:

To get at least 5,000.
Your Payoff The Reason for Your Decision on Investment Number
5766

To get at least 5,000.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7250

The reasons for your decisions on participation:

The same as the above.

317

I wanted to get at least 5,000 points. I expected the other person not to invest more than 12. Therefore it would be good forboth of us to choose 6-8.
When the person you were paired with did not participate in investment:
I chose the number maximizing my own payoff. But as an exception, I chose a number so that I was even with the otherperson once.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
It would be good to participate in investment positively in an attempt to gain around 7,000-8,000, because a cunning plan isseldom successful. Many people thought that their opponent did not want to make a profit.

318

ID Number = 9, Male, Earnings = 3373 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

The
Person ...
O
¯

12

4

2700

I chose a safe number because I could not expect which number theother person would choose.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation

Participation
in investmentO¯

Invest. Num.
Practice 3

13

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.

11

7

Practice 4

Participation
in investment

You

You
´
¯

Invest. Num.

The
Person ...
O¯
6Period 1 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

Invest. Num.

7

12Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

7

8

PayoffTable

The Reason for Your Decision on Participation
Because choosing participation would be less risky.

Your Payoff The Reason for Your Decision on Investment Number

Because this is less risky.
Your Payoff The Reason for Your Decision on Investment Number
1631

Because my own payoff is maximized.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
3792

PayoffTable

I chose a number leading to a large payoff for the number the otherperson chose at practice 1.
The Reason for Your Decision on Participation
Because I have participated in investment at all previous periods.

Your Payoff The Reason for Your Decision on Investment Number
1416

PayoffTable

The Reason for Your Decision on Participation

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
7
12Period 4 of the Actual Experim1ent
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

7

3

Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
7
5
Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment
¯
¯

11480

Because I expected the other person to choose a small number, I chose anumber leading to a large payoff for such a number.

Invest. Num.
87Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

PayoffTable

The Reason for Your Decision on Participation

Invest. Num.

Because this is less risky.

Period 9 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

Because at a practice period, when I did not participate in investment,
the other person took behavior so as to reduce my payoff rather thanmaximize his payoff.
Your Payoff The Reason for Your Decision on Investment NumberYour Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

Invest. Num.

319

8

8

8

6

PayoffTable

The Reason for Your Decision on Participation
Because the case in which both the other and I choose participation isbeneficial to both.

Your Payoff The Reason for Your Decision on Investment Number
11480

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

I chose a number so as not to make the payoff of the other person large.

PayoffTable

The Reason for Your Decision on Participation
Because the case in which both the other and I choose participation ismost beneficial to both, and participation is less risky.

Your Payoff The Reason for Your Decision on Investment Number
3675

Payoff
Table

Because I can get a reasonable payoff even if the other chooses a small
number.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
4950

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

Because the numbers that the other persons chose become smaller.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

I expected the other person to choose a number between 4 and 8. I
chose a number so as to make my own payoff large for such a number.

PayoffTable

The Reason for Your Decision on Participation

The case in which both I and the other choose participation is beneficial
to both. The persons I was paired with participated in investment at
most periods. I would like to avoid the case in which neither participatesin investment.
Your Payoff The Reason for Your Decision on Investment Number
5766

I chose a number so as to make my own payoff large for numbers
around 7 that many of the persons I was paired with chose.

320

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

6

8

9

Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

Invest. Num.

8

10Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

88Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

8

8The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2003

Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

Invest. Num.

Payoff
Table

PayoffTable

I chose a number so as to prevent the other person from receiving alarge payoff.
The Reason for Your Decision on Participation

Because I would not get a large payoff even if I choose non-participationand the case ´O happens. There is no reason why I should choose nonparticipation.
Your Payoff The Reason for Your Decision on Investment Number
8225

I chose a number so as to make my own payoff large for numbers
around 7 that the other person would choose.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation

The case in which both the other person and I choose participation ismost beneficial to both. The persons I was paired with participated ininvestment at most periods. Participation is less risky.
Your Payoff The Reason for Your Decision on Investment Number
9168

I chose a number so as to make my own payoff large for the numbersthat many of the persons I was paired chose in the past (6,7,8, or 9).

PayoffTable

The Reason for Your Decision on Participation

ID Number = 9, Male, Earnings = 3373 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I looked at Payoff Table 1 mainly. I sometimes referred to Supplemental Payoff Table 1-1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
I basically chose a number so as to make my own payoff large. However, in the case O´ in which I participated ininvestment, but the other person did not, I attempted to reduce the payoff of the other person.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
The case in which both the other person and I choose participation is most profitable. I would not get a large payoff evenwhen the other person chooses participation, but I do not.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
I expected which number the other person would choose, and I chose a number so as to maximize my payoff for the numberof the other person that I expected.
When the person you were paired with did not participate in investment:

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
7345

I know that the case in which both choose 12 is most profitable to both.
However, this is the only number that I can choose because the otherperson would choose a number between 6 and 10.

PayoffTable

The Reason for Your Decision on Participation

I chose a number so as to keep my payoff reasonably large and make the payoff of the other person small.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
I think it is the best that both choose participation. If both choose non-participation, then both suffer losses. If only one
person chooses participation, the participant would often take behavior so as to reduce the payoff the non-participant.
I know that the case in which both choose 12 is most profitable to both. However, I always chose 7 or 8, because I expected
the other person would choose a number between 5 and 10.

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

321

322

ID Number = 10, Female, Earnings = 1970yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.

Practice 3

You
O
¯

The
Person ...
´
¯

13

You
O
¯

The
Person ...
´¯

0

The Reason for Your Decision on Participation
I thought it is better to participate in investment so as to see what
happens in the experiment.

Your Payoff The Reason for Your Decision on Investment Number
1631

I chose the number that maximizes my payoff, because the otherperson did not participate in investment.

PayoffTable

The Reason for Your Decision on Participation
To see which number the other person chooses if he participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
500

Participation
in investmentO¯

Invest. Num.

4

8

3701

Because the ID number of the other person is 4. I hope that he is anice person and choose a large number.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.

15

9Period 1 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
06Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

24

7

PayoffTable

I cannot believe people because non-participation has been chosen. I
treated the other person to a painful experience. This is just a practiceperiod.

The
Person ...
O¯

Practice 4

You

PayoffTable

The Reason for Your Decision on Participation
I believe the other person to be nice this time.

Your Payoff The Reason for Your Decision on Investment Number

Because it is more interesting to consider which number I shouldchoose after selecting participation. I do not want to displease the otherperson.
Your Payoff The Reason for Your Decision on Investment Number
3653

PayoffTable

The other person will be happy if I choose a relatively large number.
This is also a safe number for me.

The Reason for Your Decision on Participation
Because I could not go on a gamble if I did not participate ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
3244

Because I have already decided to choose this number at first.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
0
Period 4 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

Invest. Num.
15
6Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

08Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

67

Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
1
9Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

12

8

PayoffTable

The Reason for Your Decision on Participation
Because I had not chose non-participation.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation

Because I was a little damaged by the painful treatment of the otherperson at the last period, although I know the person I am paired withat this period is different from the person at the last period.
Your Payoff The Reason for Your Decision on Investment Number
4065

Because the ID number of the other person is 15.

PayoffTable

The Reason for Your Decision on Participation
Because choosing participation is more interesting.

Your Payoff The Reason for Your Decision on Investment Number
4904

The persons I was paired with had chosen safely the numbers around 6
or 7. I do no like that they attempted to get payoffs that are larger thanmine. I could not receive large payoffs.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6339

Because the ID number of the other person is 6. Everybody has thesame idea if he choose a number between 5 and 10. It is not interesting.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6475

It is not interesting to choose 0 all the time.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6385

Because I find that if everybody in this room invests 12, then he gets thelargest payoff safely. But why do people want to get a little larger
payoffs than the others do?

Your Payoff The Reason for Your Decision on Investment Number
500

The person who runs the risk in the actual experiment is a real gambler.

323

324

Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

240Period 11 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

124Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
126Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

12

7

The Reason for Your Decision on Participation
Because it is fun to see behavior of the other person by participating ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
500

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

Payoff
Table

PayoffTable

First I thought I should get revenge on the other person. But I did not.
Instead, I chose an unusual number because the difference of my payoffs
is only 200.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
706

I got revenge on the other person. I was not magnanimous enough toinvest 24 twice.

PayoffTable

The Reason for Your Decision on Participation
Revenge. I also want to see how the other person will respond to this.
Will everybody choose 0?

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

ID Number = 10, Female, Earnings = 1970yen.
(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 2) in Practice(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
At the beginning I considered the case O´ by looking at Payoff Table 2, and found that the other person gets a large payoff.
Then I considered how the other person would behave by looking at Payoff Table 1.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify). It depends on my mood. Because the others invested similar units, I did not like tochoose numbers similar to them. I am angry that the maximum of the numbers the others chose was 9.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:

The Reason for Your Decision on Participation
I believe that the other person chooses participation this time. I would
like to see his behavior.

Your Payoff The Reason for Your Decision on Investment Number
4250

The same as the reason when I chose 12 last time. Is there anyone who
has the same idea as mine?

PayoffTable

The Reason for Your Decision on Participation
I wish the other person might also choose participation.

Your Payoff The Reason for Your Decision on Investment Number5249

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Because I understood that choosing non-participation does not mean that I can run a great risk.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
It depended on my mood at the beginning. But after seeing the whole investment pattern, I understood that I could not get alarge payoff by investing an extreme number. I also tried to realize the situation in which everybody gets the highest equal
payoff, but I failed. At last I found that choosing 8 is safe.
When the person you were paired with did not participate in investment:
0 or 24. No other choice. When non-participation was selected many times, I could not be magnanimous.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Everybody should invest 12. It is sad that because all people are selfish, the payoffs that they can get are smaller than thehighest equal payoff. I think it is better that everyone becomes happy.

Your Payoff The Reason for Your Decision on Investment Number
7345

I would get a reasonably large payoff by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5800

Because I stick to this number. The other person will also be happy
somewhat.

325

326

ID Number = 11, Female, Earnings = 2574yen
Practice 1

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.

11

10

5407

By choosing this number, my payoff is high if the other person chooses
more than 12, and the loss of my payoff is the smallest
even if he chooses less than or equal to 12.

You

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation

Practice 2

Participation
in investment

Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You

´
¯

The Reason for Your Decision on Participation

My payoff is the highest when I invest 0 and the other person invests 24.
But I chose participation to see how the other person will behave. (If I
choose ´, then the other person would also invest nothing.
Your Payoff The Reason for Your Decision on Investment Number

To check the response of the other person. I would like to see whether
or not the other person invests 13 that maximize his own payoff when I
do not participate in investment.
Your Payoff The Reason for Your Decision on Investment Number

0500
Payoff
Table

O
¯

The
Person ...
O
¯

7

12

7234

My payoff is not bad if the other person chooses a similar number. If hechooses more than 8, then my payoff becomes high.

You

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation

You

´
¯

Invest. Num.

13

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

Invest. Num.

Payoff
Table

14

8

The Reason for Your Decision on Participation
I want to see whether or not the other person chooses participation andthen invests 0, when I choose participation.

Your Payoff The Reason for Your Decision on Investment Number

To check the response of the other person once more. I want to see
whether or not the other person will punish me. The same as period 2.
Your Payoff The Reason for Your Decision on Investment Number
6117

PayoffTable

Invest. Num.

127Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

96Period 6 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

The Reason for Your Decision on Participation

Invest. Num.

To increase my payoff. If I do not participate in investment, then mypayoff might be 706.

Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯Your Payoff The Reason for Your Decision on Investment Number
2658

I chose the number maximizing my own payoff.

PayoffTable

The Reason for Your Decision on Participation

Because I could not choose a large investment number if I did notparticipate in investment, and everybody will choose a smaller number
if the investment number is not large.
Your Payoff The Reason for Your Decision on Investment Number
5393

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

I chose a number so that my payoff is little influenced even if the otherperson chooses 0.

Invest. Num.

8

6

6

Period 9 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

327

3

6

7

PayoffTable

The Reason for Your Decision on Participation
To get a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
5800

Because the other person would not choose more than 20, this is areasonable number.

PayoffTable

The Reason for Your Decision on Participation
I hoped that the other person would invest 11. If so, then I can get 8278.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I will invest a rather small number after choosing participation.

Your Payoff The Reason for Your Decision on Investment Number
5765

By choosing this number, I am not in trouble even if the investment
number of the other person is small. My payoff is large if it is at least 4.

PayoffTable

The Reason for Your Decision on Participation
Because non-participation is the final strategy to increase my payoff.

Your Payoff The Reason for Your Decision on Investment Number2658

To make my payoff the highest.

PayoffTable

The Reason for Your Decision on Participation
I want to try a small number after choosing participation.

Your Payoff The Reason for Your Decision on Investment Number
4590

The other person would not choose a large investment number. But I
would like to see what will happen if I chose a small investment number.

PayoffTable

The Reason for Your Decision on Participation
Choosing participation is more interesting because I have many options.

Your Payoff The Reason for Your Decision on Investment Number
5766

I expected the other person to choose around 6-8. I chose 8 that leads
to the highest payoff for those numbers.

PayoffTable

The Reason for Your Decision on Participation
Everybody seems to choose around 6. I participated in investment to see
whether or not that is true.

Your Payoff The Reason for Your Decision on Investment Number6339

I expected everybody to invest around 6. That seems to be true.

328

Period 10 of the Actual Experiment
You
The
Person ...
Participation´´
in investment¯¯
Invest. Num.
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

13

7

Period 12 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

11

Period 13 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

68Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

9

7

PayoffTable

The Reason for Your Decision on Participation
Because I have been at a deadlock, I chose non-participation that leads tothe highest payoff.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I will let the other person dream of his success.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 11, Female, Earnings = 2574 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
First I drew lines indicating high payoffs in the rough payoff table (the supplemental payoff table 1-1). Then I looked at thedetailed payoff table 1. I expected that everybody would choose around 6-9.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?

5406

I expected the other person to choose a number between 3 and 6. I am
satisfied with 3,000-4,000 units of payoff. But my payoff is less than ahalf of the other person's.

PayoffTable

The Reason for Your Decision on Participation(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

It is reasonable to participate in investment and then choose around 6-7.

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.

Your Payoff The Reason for Your Decision on Investment Number

3. It is desirable that both my payoff and the payoff of the person I am paired with are as high as possible.

2658

The other person is also at a deadlock. I was forced to choose thenumber maximizing my payoff.

The reasons for your decisions on participation:

PayoffTable

The Reason for Your Decision on Participation(6) How did you choose your investment number when you participated in investment?

I am aiming at recovering my lost position.

When the person you were paired with participated in investment:

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
I want to avoid the situation in which neither participates in investment.

Your Payoff The Reason for Your Decision on Investment Number
7237

I chose a safe number. The other person would choose a similar
number, because he has the similar experiences.

PayoffTable

The Reason for Your Decision on Participation

When I participates in investment, my payoff was small. Therefore I sometimes chose non-participation.

I expected the other person to choose a number between 6 and 9. I chose a number not to suffer a loss when the other person
chose such a number. I chose large numbers at the early stage and then smaller numbers between 6 and 9.
When the person you were paired with did not participate in investment:
I always chose "11" so as to maximize my payoff when the other person did not participate in investment.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
It is good to choose a number between 6 and 9 usually, but choose non-participation sometimes (by expecting when theother person participates in investment). The sum of my payoffs would be the highest if I did not participate in investment
at all periods.

Your Payoff The Reason for Your Decision on Investment Number
6481

329

330

ID Number = 12, Male, Earnings = 3305 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

The
Person ...
´
¯

13
You
´
¯

You
´
¯

The
Person ...
O¯

Your Payoff The Reason for Your Decision on Investment Number
1631

Because my payoff is the highest.

PayoffTable

The Reason for Your Decision on Participation
Because I get a large payoff if the other person chooses a large number.

Your Payoff The Reason for Your Decision on Investment Number
6117

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
500

You
O
¯

The
Person ...
O
¯

13

15

7

8

Period 2 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

The Reason for Your Decision on Participation
Because I can get the highest payoff on average by participating ininvestment.

13

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

PayoffTable

6

PayoffTable

The Reason for Your Decision on Participation
Because the other person seems to participate in investment, too.

Your Payoff The Reason for Your Decision on Investment Number
7335

Payoff
Table

Because my payoff would be about average.

The Reason for Your Decision on Participation
Because choosing participation is more interesting.

Your Payoff The Reason for Your Decision on Investment Number
7340

Payoff
Table

Because I expected the other person to choose a number between 7 and
9.
The Reason for Your Decision on Participation
Because the other person might choose a large investment number(people usually choose 11).

Your Payoff The Reason for Your Decision on Investment Number
3244

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
3
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 6 of the Actual Experiment
You
The
Person ...
Participation´´
in investment¯¯
Invest. Num.
Period 7 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
9
Period 8 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

331

24

PayoffTable

The Reason for Your Decision on Participation
Because the other person would usually choose 11 if he participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
The other person would usually choose 11 if he participates ininvestment. Then my payoff is not bad.

Your Payoff The Reason for Your Decision on Investment Number
1554
PayoffTable

The Reason for Your Decision on Participation
Because choosing participation seems to be more profitable.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because this would be the most reasonable number.

PayoffTable

The Reason for Your Decision on Participation
Because the other person would usually choose 11 if he participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because the other person would usually choose 11 if he participates ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
5907
PayoffTable

The Reason for Your Decision on Participation
Because choosing participation seems to be more profitable.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my own payoff is maximized by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
I wish the other person to participate in investment and then choose 11.

Your Payoff The Reason for Your Decision on Investment Number
37111

332

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
1
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 12 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 13 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 14 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

11

PayoffTable

The Reason for Your Decision on Participation
I wish the other person to be generous.

Your Payoff The Reason for Your Decision on Investment Number
905
PayoffTable

ID Number = 12, Male, Earnings = 3305 yen.
(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 2) in Practice(2) Did you understand the three kinds of payoff tables?

The Reason for Your Decision on Participation
Because I understood that there are persons who do not care about theirown payoffs, I participated in investment this time.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my own payoff is maximized.

PayoffTable

The Reason for Your Decision on Participation
Because I may be paired with a generous person once more.

1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
First I looked at the supplemental payoff tables to understand the payoff structure roughly. Then I decided my investment
numbers by using the detailed payoff tables.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of the payoff of the person I am paired with.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation

4. I participated in investment several times, but the number of periods at which I did not participate in investment
was greater than the number of periods at which I did.

Because choosing participation seems to be more profitable.

The reasons for your decisions on participation:

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my own payoff is maximized.

PayoffTable

The Reason for Your Decision on Participation
I wish the other person to participate in investment.

Your Payoff The Reason for Your Decision on Investment Number

I expected the other person to choose around 7-9 if both participate in investment, and to choose 11 usually if only heparticipates in investment.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
I chose numbers that seemed be safe.
When the person you were paired with did not participate in investment:

8278
PayoffTable(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

The Reason for Your Decision on Participation

I chose the number maximizing my own payoff.

Because the other person would usually choose 11 if he participates ininvestment.

(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

Your Payoff The Reason for Your Decision on Investment Number
8278

333

I think that it is the best to choose an investment number so that I suffer no loss although my payoff is not very large.

334

ID Number = 13, Male, Earnings = 2553 yen.
Practice 1
You
The
Payoff
The Reason for Your Decision on Participation
Person ...
Table
Participation
Because it is more likely that I get a large payoff by participating inOOin investment
investment.
¯¯Your Payoff The Reason for Your Decision on Investment Number
Invest. Num.
Practice 2

10

0

1503

Because my payoff seems to be about average by choosing this number.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.

0

0

500

Because my payoff was smaller than the other person's was at the lastperiod, I chose the same strategy as his.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation

Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

O
¯
0
You
´
¯

The
Person ...
´¯Invest. Num.
Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

0

Period 2 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

0

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

07

I want to get a large payoff by participating in investment.
Your Payoff The Reason for Your Decision on Investment Number

Because I can get only 500 if I do not participate in investment.
Your Payoff The Reason for Your Decision on Investment Number
500

I do not like to give the other person a large payoff.

PayoffTable

The Reason for Your Decision on Participation
I want to see how the other person will respond when I do not participate
in investment.

Your Payoff The Reason for Your Decision on Investment Number
500
PayoffTable

The Reason for Your Decision on Participation
Because it is more likely that I will get a large payoff by choosing
participation.

Your Payoff The Reason for Your Decision on Investment Number

You
Participation
in investment

O
¯

The
Person ...
´¯Invest. Num.
3
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

67

Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

68Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

63

Period 8 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment
¯
¯

706

Because I do not like to give the other person a large payoff when he does
not participate in investment.

Invest. Num.

PayoffTable

The Reason for Your Decision on Participation

Period 9 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯I believe that I can get a large payoff if I participate in investment.
Your Payoff The Reason for Your Decision on Investment Number
706

Because I do not like to give the other person a large payoff when he does
not participate in investment.

PayoffTable

The Reason for Your Decision on Participation

Invest. Num.

3

6

8

PayoffTable

The Reason for Your Decision on Participation
Because choosing participation is more interesting.

Your Payoff The Reason for Your Decision on Investment Number
1297

I accept the small difference between my payoff and the other person's.

PayoffTable

The Reason for Your Decision on Participation
The deep game with the other person after choosing participation isinteresting.

Your Payoff The Reason for Your Decision on Investment Number
6339

Because I expected the other person to choose a similar investment
number.

PayoffTable

The Reason for Your Decision on Participation
Because I surely get more than 706 by participating in investment.

Your Payoff The Reason for Your Decision on Investment Number
7237

Payoff
Table

Because I expected the other person to choose a large investment number
so as to get a high payoff.
The Reason for Your Decision on Participation
Because I can get a larger payoff by participating in investment.

Your Payoff The Reason for Your Decision on Investment Number
3463

Because of my success at the last two periods. I expected the other person
to choose a similar investment number.

PayoffTable

The Reason for Your Decision on Participation
Because participating in investment is more interesting.

Your Payoff The Reason for Your Decision on Investment Number
1297

I chose a number so that the difference between my payoff and the payoffof the other person is as small as possible and the absolute value of mypayoff is moderate.

PayoffTable

The Reason for Your Decision on Participation
I can get at least 706 by participating in investment.

Your Payoff The Reason for Your Decision on Investment Number
7237

Because 6 would be the average investment number.

Because I think I can decide my payoff by myself if I choose participation.
Your Payoff The Reason for Your Decision on Investment Number
4018

Because it is likely that I get a larger payoff than the other person does bychoosing this number.

Period 4 of the Actual Experiment

335

336

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

69Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

67

Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

68Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
612Period 14 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

3

Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

6

11

PayoffTable

The Reason for Your Decision on Participation
I want to get at least 706 surely.

Your Payoff The Reason for Your Decision on Investment Number
8209

PayoffTable

Choosing 7 or 8 seems to be the average investment number. I want to
get a larger payoff than the other person does.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 13, Male, Earnings = 2553 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I actually used only the payoff tables 1 and 2.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?

6339

Because choosing 6 has been successful many times. My payoffs werereasonably large, and they were larger than the payoffs of the otherpersons.

2. If my payoff is higher than the payoff of the person I am paired with, I do not care about the absolute value of
my payoff, even when the difference between my payoff and the payoff of the person I am paired with is small.

PayoffTable

The Reason for Your Decision on Participation(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.

The same as the above.

The reasons for your decisions on participation:

Your Payoff The Reason for Your Decision on Investment Number
7237

Payoff
Table

Because by choosing 6, my payoff would be larger than the payoff of theother person, and the absolute value of my payoff would be reasonably
large.

(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:

The Reason for Your Decision on Participation

I looked for a number such that I could get a larger payoff than the other person did, and the absolute value of my payoff
was reasonable. I decided it based on my past experiences, and continued to choose it.

The same as the above.

When the person you were paired with did not participate in investment:

Your Payoff The Reason for Your Decision on Investment Number
11589

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
1297

I chose a number so that the difference between my payoff and the payoffof the other person is as small as possible and the absolute value of mypayoff is moderate.

PayoffTable

The Reason for Your Decision on Participation

First I invested 0 so as not to give the other person a large payoff. But my payoff was small by doing so. Therefore I chose anumber so that the difference between my payoff and the other person's was small, but the absolute value of my payoff was
reasonably large.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
It is the best to participate in investment and choose an investment number so that I can get a larger payoff than the otherperson does and the absolute value of my payoff is moderate.

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
10384

Because by choosing 6, I would obtain a larger payoff than the otherwould, and the absolute value of my payoff would be reasonably large.

337

338

ID Number = 14, Male, Earnings = 2818 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You
O
¯

The
Person ...
O
¯

6

10

5561

I expected the investment number of the other person to be around 8.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation

O
¯
13
You
´
¯

You
´
¯

The
Person ...
O¯

The Reason for Your Decision on Participation
I want to understand the method of investment because this is a practiceperiod.

Your Payoff The Reason for Your Decision on Investment Number

I want to get used to the method of investment.
Your Payoff The Reason for Your Decision on Investment Number
1631

I chose the investment number maximizing my payoff.

PayoffTable

The Reason for Your Decision on Participation
I am tired.

Your Payoff The Reason for Your Decision on Investment Number

6

1416

The
Person ...
´¯

PayoffTable

Invest. Num.

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
912Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

PayoffTable

9

6

PayoffTable

The Reason for Your Decision on Participation
Because choosing an investment number is more interesting.

Your Payoff The Reason for Your Decision on Investment Number
10877

I expected the other person to choose 8.

PayoffTable

The Reason for Your Decision on Participation
Choosing an investment number seems to be more profitable.

Your Payoff The Reason for Your Decision on Investment Number
5765

Because choosing 9 resulted in a large payoff at the last period.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
910Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
98Period 6 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
91
Period 8 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
9
Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

339

11

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8951

I want to see what will happen by choosing 9 once more.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2658

My payoff is the highest when I choose this number.

PayoffTable

The Reason for Your Decision on Participation
I did not mean to participate in investment, but I unconsciously did.

Your Payoff The Reason for Your Decision on Investment Number
7250

I expected the other person to choose around 7.

PayoffTable

The Reason for Your Decision on Participation
I am tired.

Your Payoff The Reason for Your Decision on Investment Number
2017
PayoffTable

The Reason for Your Decision on Participation
Because choosing non-participation was a mistake at the last period.

Your Payoff The Reason for Your Decision on Investment Number
2944
PayoffTable

The Reason for Your Decision on Participation
Choosing an investment number seems to be more profitable.

Your Payoff The Reason for Your Decision on Investment Number
2523

For no particular reason.

PayoffTable

The Reason for Your Decision on Participation
Because the other persons have chosen small investment numbers since alittle while ago.

Your Payoff The Reason for Your Decision on Investment Number
8278

340

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 12 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
4
Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
108Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
98Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

6

6

PayoffTable

The Reason for Your Decision on Participation
Because I do not have to choose an investment number.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?

Because many people seem to choose participation.

I looked at Payoff Tables 1 and 2 mainly.

8278
The Reason for Your Decision on Participation
Because choosing non-participation has been successful recently.
Your Payoff The Reason for Your Decision on Investment Number
2017
PayoffTable(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number

PayoffTable

ID Number = 14, Male, Earnings = 2818 yen(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of the payoff of the person I am paired with.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:

The Reason for Your Decision on Participation
Always choosing non-participation is not fun.

Your Payoff The Reason for Your Decision on Investment Number
7056

I expected the other person to choose about 6.

PayoffTable

The Reason for Your Decision on Participation
For no particular reason.

Your Payoff The Reason for Your Decision on Investment NumberFirst I thought the other persons would choose the investment number so that their payoffs become the highest if I did notparticipate in investment. But because the numbers they actually chose were smaller than that number, I could not get large
payoffs as I expected. Therefore I decided to choose an investment number again.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
Based on my expectation on which investment number the other person would choose.
When the person you were paired with did not participate in investment:
I chose my number so as to make my own payoff as large as possible.

7250

I expected the other person to choose around 8.

PayoffTable

The Reason for Your Decision on Participation(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

The other person would be pitiful if I did not participate in investment.

I had not been able to find it through the experiment.

Your Payoff The Reason for Your Decision on Investment Number
5515

I expected the other person to choose 11.

341

342

ID Number = 15, Male, Earnings = 3316 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

You
O
¯

The
Person ...
O
¯

8

12

7206

I expected the other person to invest around 12. My investment numberthat leads to a large payoff when he invests 12 is between 7 and 9.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.

8

11

Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment

You
´
¯

You
´
¯

The
Person ...
O¯

The Reason for Your Decision on Participation
To practice on the investment.

Your Payoff The Reason for Your Decision on Investment Number

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
6446

PayoffTable

I expected the other person to choose a number between 10 and 12.
My investment number that leads to a large payoff when he invests sucha number is between 7 and 9.
The Reason for Your Decision on Participation
To see what will happen when I do not participate in investment.

Your Payoff The Reason for Your Decision on Investment Number

7

1815

The
Person ...
´¯

PayoffTable

Invest. Num.

The Reason for Your Decision on Participation

Your Payoff The Reason for Your Decision on Investment Number
500

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

PayoffTable

6

9

PayoffTable

The Reason for Your Decision on Participation
To avoid the situation ´´.

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff is maximized by choosing this number.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8209

Because I anticipated that the other person would choose 12.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
68Period 4 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
615
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
67
Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
68Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

343

11

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
15694

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number6339

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7237
PayoffTable

The same as the above.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

To induce everyone to invest 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
Because I would obtain a larger payoff by choosing non-participation
than by choosing participation and then investing 6, 7, or 8.

Your Payoff The Reason for Your Decision on Investment Number
8278

344

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
7
13
Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 13 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
3
Period 14 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 15 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

11

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation
Because there might be a person who takes a similar action as the person
I was paired with at the last period did.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 15, Male, Earnings = 3316 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?

12694

Because I expected the other person to choose 6, 7, or 8.

PayoffTable

The Reason for Your Decision on Participation(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

The same as the above.

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.

Your Payoff The Reason for Your Decision on Investment Number

1. It is desirable that my payoff is as high, regardless of the payoff of the person I am paired with.

7340

The same as the above.

The reasons for your decisions on participation:

PayoffTable

The Reason for Your Decision on Participation

I initially participated in investment to avoid the situation in which neither participated in investment. However, because I
thought my payoff would be larger when I did not choose participation, but the other person did, I did not choose
participation several times.

Because I would obtain a larger payoff by choosing non-participation
than by choosing participation and then investing 6, 7, or 8.
Your Payoff The Reason for Your Decision on Investment Number

When the person you were paired with participated in investment:

1554
PayoffTable

The Reason for Your Decision on Participation

I initially expected the investment number of the other person to be between 6 and 12. As rounds advanced, I changed my
expectation: I expected it to be 6, 7 or 8 at the middle periods and to be 8 at the latter periods. I invested 6 or 7.

Because there might be a person who takes a similar action as the person
I was paired with at the last period did.

When the person you were paired with did not participate in investment:

Your Payoff The Reason for Your Decision on Investment Number
2658

Because my payoff becomes the largest by choosing this number.

PayoffTable

The Reason for Your Decision on Participation

I invested 11 so as to maximize my own payoff.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

The same as the above.

Participate in investment at all periods. Invest 6, 7, or 8 if the other person participates in investment, and invest 11
otherwise.
I expected the other person to choose a number between 6 and 12 at the initial periods, 6, 7, or 8 at the middle periods and 8
at the latter periods. Further I expected that the number of persons who do not choose participation and let the other personchoose 11 would increase as rounds advance.

345

346

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
2658(6) How did you choose your investment number when you participated in investment?

ID Number = 16, Male, Earnings = 2682 yen
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

You
O
¯

The
Person ...
O
¯

10

6

3520

I expected the other person would also choose around 10.

You

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on Participation

´
¯

You

PayoffTable

The Reason for Your Decision on Participation
To understand the outline of the game.

Your Payoff The Reason for Your Decision on Investment Number

To see what will happen.
Your Payoff The Reason for Your Decision on Investment Number

13

6117
PayoffTable

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.
Practice 4

8

9

5080

For no particular reason.

You

PayoffTable

The Reason for Your Decision on Participation

Participation
in investment

O
¯

The
Person ...
O¯

Invest. Num.

15

13

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
11
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

0

The Reason for Your Decision on Participation
To prevent the other person from choosing non-participation.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
2
Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯Your Payoff The Reason for Your Decision on Investment Number

It seems that many people choose a number between 6 and 10.

Invest. Num.
78
Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯Your Payoff The Reason for Your Decision on Investment Number
5026

I made the other person happy.

PayoffTable

The Reason for Your Decision on Participation
I believe the other person should choose participation.

Your Payoff The Reason for Your Decision on Investment Number

Invest. Num.
78
Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

7

7

PayoffTable

The other person should choose 11 this time.
Your Payoff The Reason for Your Decision on Investment Number
1186
PayoffTable

The Reason for Your Decision on Participation
The other person should choose participation and then invest 11.

Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯Your Payoff The Reason for Your Decision on Investment Number
Invest. Num.
78
Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment
¯
¯

706

Invest. Num.

347

6

The Reason for Your Decision on Participation
Everybody is spiteful. However, I still believe the other person shouldchoose 11 this time.

Your Payoff The Reason for Your Decision on Investment Number
4018
PayoffTable

The Reason for Your Decision on Participation

My theory seems to be wrong. According to my analysis, a human being
cares about not only his payoff, but also the payoff of the other. He
prevents the other from obtaining a large payoff unfairly even when hemust lose his own payoff.
Your Payoff The Reason for Your Decision on Investment Number
7340
PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340
PayoffTable

The Reason for Your Decision on Participation
I no longer conduct myself badly.

Your Payoff The Reason for Your Decision on Investment Number
6478

Everybody seems to choose 8 so as to obtain a large payoff. I do not likethat the other person obtains a larger payoff than I do. A little revenge.

PayoffTable

The Reason for Your Decision on Participation

8278
PayoffTable

The Reason for Your Decision on Participation

I will continue to participate in investment.
Your Payoff The Reason for Your Decision on Investment Number
7340
PayoffTable

The Reason for Your Decision on Participation
The nail that sticks out will get a pounding.

Your Payoff The Reason for Your Decision on Investment Number
2003

I finally meet a foolish person.

348

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

6

Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
7
4
Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

7

9

PayoffTable

The Reason for Your Decision on Participation
I felt refreshed a little. However, I cannot endure that the other person
obtained a larger payoff than I did.

Your Payoff The Reason for Your Decision on Investment Number
7340

I decide to choose 7. I expected the other person to choose 7 or 8.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2003

I meet a foolish person. I now understand how the persons I was pairedwith at periods 2 and 3 felt.

PayoffTable

The Reason for Your Decision on Participation
The nail that sticks out will get a pounding.

ID Number = 16, Male, Earnings = 2682 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I used Table 1 to examine what my payoff was.
I used Table 1-2 to decide my plan.
I used Table 2-2 to decide how I reacted when the other person chose non-participation.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).

7340

The same as the reason at period 10.

When the other person participate in investment: Basically 1 (it is desirable that my payoff is as high, regardless ofthe payoff of the person I am paired with), but if my payoff did not change much, then 2 (if my payoff is higher than the
payoff of the person I am paired with, I do not care about the absolute value of my payoff, even when the difference between
my payoff and the payoff of the person I am paired with is small).

PayoffTable

The Reason for Your Decision on Participation

When the other person did not participate in investment: the middle between 1 and 4 (if I can make the payoff ofthe person I am paired with as small as possible, it is fine that my payoff is moderate).

The same as the above.

(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

Your Payoff The Reason for Your Decision on Investment NumberYour Payoff The Reason for Your Decision on Investment Number
4281

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8271

The same as the above.

3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
First I intended not to participate in investment at all periods. But I was spiritually wakened in the middle of theexperiment. See my record sheets for my feelings. I have participated in investment from period 5.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
7.
When the person you were paired with did not participate in investment:
6. Many people would not participate in investment if I permitted the other persons to obtain large payoffs. But I did not
like to make my own payoff small.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Participate in investment at all periods. Invest 7 if the other person participates in investment. In this case, I should cho ose 7
or 8, but I like to behave spitefully. Invest 6 if the other person does not participate in investment. The reason is statedabove.

349

350

ID Number = 17, Male, Earnings = 3039 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
O
¯

The
Person ...
O
¯

0

10

3536

I expected the other person to choose a large number at the first time.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

The
Person ...
O
¯

10

9

5019

This is a safe number.

You

PayoffTable

The Reason for Your Decision on Participation

O
¯

The
Person ...
O
¯

9

8

4512

I chose a safe number once more.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation

O¯
13

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
129Period 2 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

6

PayoffTable

The Reason for Your Decision on Participation
I want to choose a number at the first time.

Your Payoff The Reason for Your Decision on Investment Number

I want to choose a number once more because I made a mistake atpractice 1.
Your Payoff The Reason for Your Decision on Investment Number

The payoff that I can obtain by choosing non-participation would be at
most 9112.
Your Payoff The Reason for Your Decision on Investment Number

Because I can not earn a large payoff by choosing non-participation.
Your Payoff The Reason for Your Decision on Investment Number
1631

PayoffTable

No other choice.

The Reason for Your Decision on Participation
Because the payoff that I can obtain by choosing non-participation would
be at most 9112, I do not have to take a risk.

Your Payoff The Reason for Your Decision on Investment Number
7007

I chose a safe number at the beginning of the experiment.

PayoffTable

The Reason for Your Decision on Participation
The same as the reason at period 1.

Your Payoff The Reason for Your Decision on Investment Number
2003

I emotionally chose this number so as to prevent the other person fromobtaining a large payoff easily, because he chose non-participation.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
98Period 4 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
110
Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
7
6
Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
118Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

6

Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

98Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

351

9

7

PayoffTable

The Reason for Your Decision on Participation
The same as the aboveYour Payoff The Reason for Your Decision on Investment Number
7250

Because I expected the other person to choose 10, 11, or 12 safely.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2658

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5681

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6765
PayoffTable

The same as the above.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5765

There is a tendency for the other persons to choose small numbers.
Therefore, I chose a safer number.

PayoffTable

The Reason for Your Decision on Participation
Because there is not much to be gained by choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7250

People might not seriously consider which number they should choose
because they would become tired in the middle of the experiment.
Therefore I chose a safe number.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
2210

I did not give the other person a large payoff so as to prevent choosing
non-participation from spreading.

352

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
97
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
98Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

97

Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

7

7

Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
78
Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

7

12

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6481

I expected the other person to take a risk at the middle stages.

PayoffTable

The Reason for Your Decision on Participation
I expected that nobody would choose non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7250

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6481

PayoffTable

The payoff I earn by choosing a number between 6 and 8 is not very
different from that by choosing 9 when the other person chooses around9 safely. However, it is not good that choosing a small number will
prevail.
The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6478

I hope the other person to choose a relatively large number at the final
stages.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
7340

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

ID Number = 17, Male, Earnings = 3029 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I used only Payoff Table 1 because I expected that nobody would choose non-participation eventually.
I noticed that the other person would never choose a large number after the actual experiment began.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
6. Others (please specify).
I considered how my choice would affect the other person's payoff and his subsequent behavior in addition to myimmediate payoff.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
1. I always participated in investment.
The reasons for your decisions on participation:
I did not expect the other person to choose 10, 11, or 12 naively if I chose non-participation.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
I expected that the other person would expect me to choose a number so that his payoff and my payoff were between 7,000
and 9,000. Also, both would avoid taking risks. Therefore, both would decide to choose a number between 6 and 11.
When the person you were paired with did not participate in investment:
I chose a number so that the payoff of the other person was between 4,000 and 5,000 in an attempt to prevent him fromchoosing non-participation thereafter. I did not seek to maximize my immediate payoff because the payoff difference wasless than or equal to 400.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
We should participate in investment at all periods and choose 7, 8, or 9. If all of us had good expectations, then we shouldchoose 9. However, because there are several people who sought to obtain large payoffs by choosing small numbers, itwould be the best to continue to choose a safe number, 7.

Your Payoff The Reason for Your Decision on Investment Number
11480

The same as the above.

353

354

ID Number = 18, Male, Earnings = 3160 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.

Practice 4

Participation
in investment
Invest. Num.

You
´
¯

The
Person ...
O¯

The Reason for Your Decision on Participation
I expected the other person to participate in investment because this is thefirst time. Perhaps my payoff would be 6117.

Your Payoff The Reason for Your Decision on Investment Number

13

6117
Payoff
Table

O
¯

The
Person ...
O
¯

8

12

7206

Choosing 11 or 12 seems to be good, and the other person would alsochoose such a number.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation

You

O
¯
7

You
O
¯

The
Person ...
O
¯

9

15

Invest. Num.
0
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment
¯
¯
8

14

The Reason for Your Decision on Participation
For no particular reason.

Your Payoff The Reason for Your Decision on Investment Number

To look at what will happen.
Your Payoff The Reason for Your Decision on Investment Number
1148

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯

Invest. Num.

Payoff
Table

Payoff
Table

Because by choosing this number, the difference between my payoff andthe other person's becomes small and my payoff is not very small. I wantto prevent the other person from choosing non-participation at the actual
experiment.
The Reason for Your Decision on Participation
To see what will happen.

Your Payoff The Reason for Your Decision on Investment Number
9506

I invested 8 at practice 4. I want to compare the results.

PayoffTable

The Reason for Your Decision on Participation
I expected the other person to choose participation because the benefit ofchoosing non-participation is small.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
I learned my lesson at the last period.

Your Payoff The Reason for Your Decision on Investment Number
13576

Because choosing 8 or 9 seems to be safe.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
89Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
811Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
86Period 9 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

355

3

3

PayoffTable

The Reason for Your Decision on Participation
Because I naively followed my original idea that the benefit of choosing
non-participation is small.

Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
1297

Because I would be angry with the other person if he or she obtained alarge payoff.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
8225
Payoff
Table

Because I have decided to choose 8 or 9 when I participate in investment.
The Reason for Your Decision on Participation
Because it seems to be the best choice to participate in investment andthen invest 8.

Your Payoff The Reason for Your Decision on Investment Number
10173

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
5766

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
1297

The same as the reason at period 4 of the actual experiment.

356

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 11 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
3
Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
8
10Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
8
10Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

8

8

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number

ID Number = 18, Male, Earnings = 3160 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.

6526

Because I have decided to choose 8 when I participate in investment.

PayoffTable

The Reason for Your Decision on Participation(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?

The same as the above.

I looked at Payoff Table 1.

Your Payoff The Reason for Your Decision on Investment Number
1297

The same as the reason at period 9 of the actual experiment.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number
9168

The same as the reason at period 10 of the actual experiment.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

Your Payoff The Reason for Your Decision on Investment Number(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of the payoff of the person I am paired with.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
The benefit of choosing non-participation was relatively large at the practice periods, but it was small at the actual
experiment.
(6) How did you choose your investment number when you participated in investment?

9168

The same as the above.

When the person you were paired with participated in investment:

PayoffTable

The Reason for Your Decision on Participation

I always chose 8. If the other person chooses 6 or 7, then the payoff I earn by choosing 8 is smaller than that he earns, but it
is larger than the payoff I earn by choosing 6 or 7.

The same as the above.
Your Payoff The Reason for Your Decision on Investment Number
7345

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
The same as the above.

I almost always chose at most 3. If the other person had enjoyed the benefit of non-participation, then choosing nonparticipation would have prevailed. Therefore, I chose a small number even though I knew I suffered a loss.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?

The same as the above.

First I thought that I could obtain 8278 by choosing non-participation if the other person chooses participation, because hewould choose 11 so as to maximize his own payoff. However, the other person might choose 0 emotionally. Therefore, it iseffective to continue to invest around 8. I thought that it might be good to choose non-participation only at the final period,but I actually did not. Choosing 12 would be good if all people could cooperate.

357

358

Your Payoff The Reason for Your Decision on Investment Number
7345

When the person you were paired with did not participate in investment:

ID Number = 19, Male, Earnings = 3625 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

You
O
¯

The
Person ...
O
¯

10

11

6214

Everybody seems to have the same idea.

You

The
Person ...
O¯

PayoffTable

The Reason for Your Decision on ParticipationO¯

Your Payoff The Reason for Your Decision on Investment Number
I expected the other person to choose a small number.

You

The
Person ...
´¯

PayoffTable

The Reason for Your Decision on Participation

6
You

Participation
in investmentO¯

Invest. Num.

6

The
Person ...
´¯Period 1 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment
¯
¯
8

7

Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment
¯
¯
7

24

Invest. Num.

Your Payoff The Reason for Your Decision on Investment Number
Because I am mad at the other person.

PayoffTable

The Reason for Your Decision on Participation

The Reason f

To obtain a large payoff.
Your Payoff The Reason for Your Decision on Investment Number
1007

Because I am mad at the other person.

PayoffTable

The Reason for Your Decision on Participation
I decide to participate in investment at all periods.

Your Payoff The Reason for Your Decision on Investment Number
6526

I expected the other person to choose a safe number because this is thefirst period.

PayoffTable

The Reason for Your Decision on Participation
Because I could not get a large payoff if I did not choose participation.

Your Payoff The Reason for Your Decision on Investment Number
31155

Because the person I was paired with obtained a larger payoff than I did
at the last period. Choosing 7, 8, or 9 would be good.

The Reason f

Invest. Num.
7
6
Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

87Period 7 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

68Period 9 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

359

6

Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯

To obtain a large payoff.

1007

6

Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯

For the time being I chose participation.

3224

Invest. Num.
Practice 4

Invest. Num.

Your Payoff The Reason for Your Decision on Investment Number

9O¯

Invest. Num.

The Reason for Your Decision on Participation
Because I could not practice investing if I did not choose participation.

16

Participation
in investment

Invest. Num.

Payoff
Table

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment
¯
¯

9

8

PayoffTable

The Reason for Your Decision on Participation
My payoff will never decrease by choosing participation.

Your Payoff The Reason for Your Decision on Investment Number
2003

Participate in investment. To teach the other person that choosing nonparticipation is not good.

PayoffTable

The Reason for Your Decision on Participation
I must participate in investment to obtain a large payoff.

Your Payoff The Reason for Your Decision on Investment Number
2003

To make the difference between my payoff and the other person's as
small as possible.

PayoffTable

The Reason for Your Decision on Participation
I am sure that the other person will choose participation. He gets used tothe experiment because this is the fifth time.

Your Payoff The Reason for Your Decision on Investment Number
5681

I expected the participant to choose a safe number between 7 and 10.

PayoffTable

The Reason for Your Decision on Participation
I am sure that the other person will choose participation. He gets used tothe experiment because this is the sixth time.

Your Payoff The Reason for Your Decision on Investment Number
6526

I do not want to go on a gamble. Many of the persons I was paired withchose 6, 7, or 8.

PayoffTable

The Reason for Your Decision on Participation
Because I could not obtain a large payoff if I did not participate ininvestment.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because many of the persons I was paired with chose 7.

PayoffTable

The Reason for Your Decision on Participation
Because I am sure that the other person will choose participation. He
must want a large payoff.

Your Payoff The Reason for Your Decision on Investment Number
7237

I expected the other person to choose 9 or 10 this time, although thenumber of the persons who chose more than 7 is small.

PayoffTable

The Reason for Your Decision on Participation
Everybody would choose participation. Choosing participation should
be more profitable.

Your Payoff The Reason for Your Decision on Investment Number
7250

I expected the other person to choose a safe number between 7 and 9.

360

Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

6

3

6

Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
79Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

7

3

Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

8

9The Reason for Your Decision on Participation
To obtain a high payoff.

Your Payoff The Reason for Your Decision on Investment Number
2003

Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

Payoff
Table

PayoffTable

ID Number = 19, Male, Earnings = 3625 yen(1) Did you understand the rules of the experiment?
2. I have understood the rules from a middle of the experiment:
From period ( 2) in Practice.

I cannot stand that the other person earns 8278, while my payoff is only
2658 when I choose 11 to maximize my payoff. I wish to earn at least
2000.

(2) Did you understand the three kinds of payoff tables?

The Reason for Your Decision on Participation(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?

To recover the failure at period 10. Choosing participation would be
profitable.
Your Payoff The Reason for Your Decision on Investment Number
4590

Because choosing 8 has become stereotyped recently. I wanted to changeit.

PayoffTable

The Reason for Your Decision on Participation

1. I understood all three tables.

I decided my investment number mainly by looking at Payoff Tables 1-1 and 1-2. I did not look at Payoff Tables 2 and 3, butinstead I used Payoff Table 1-1. I often chose 7 or 8 because these are safe. However, when the other persons chose 7 or 8 insuccession, I chose a smaller number to put pressure on the other. Choosing 6 or 9 did not lead to a good outcome.
Choosing 9 was good for the other person.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?

Because I have already decided to choose participation.

4. If I can make the payoff of the person I am paired with as small as possible, it is fine that my payoff is moderate.

Your Payoff The Reason for Your Decision on Investment Number(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?

8271

I expected the other person to choose a safe number.

PayoffTable

The Reason for Your Decision on Participation

The reasons for your decisions on participation:

Only three periods to go. Everybody would participate in investment.

Choosing non-participation is just like strangling myself. I always participated in investment in all practice periods as wellas in all periods of the actual experiment. I never wanted to give the other person a good payoff when he did not participate
in investment. Be choosing participation, I could choose any investment number even when the other person chose nonparticipation. However I was mad at the non-participant.

Your Payoff The Reason for Your Decision on Investment Number
3675

Because I expected the other person to choose a safe number between 7
and 9.

PayoffTable

The Reason for Your Decision on Participation
I wish the other person to choose participation. Choosing participation ismore profitable than choosing non-participation.

Your Payoff The Reason for Your Decision on Investment Number
7345

Because I expected the other person to choose a safe number.

PayoffTable

The Reason for Your Decision on Participation
Because the other person would not give me a large payoff if I did notparticipate in investment.

Your Payoff The Reason for Your Decision on Investment Number
8225

Everybody would have the same idea. I am sure that the other person
will choose 8.

361

1. I always participated in investment.

(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
I chose a number between 6 and 9 at most periods. However, when 8 had been chosen in succession, I sometimes chose asmall number like 3 to put pressure on the other person. Depending on the sum of my payoffs, I decided whether or not I
chose a safe number.
When the person you were paired with did not participate in investment:
I always choose 6 so as to make the difference of my payoff and the other person's small and keep my payoff at least 2000.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
I think it is good to choose 7 or 8 safely at every period. However, if the other person does not participate in investment,
then I should make the happiness of the other person as small as possible. My payoff was important, but I did not like theother person to earn a large payoff.

362

ID Number = 20, Male, Earnings = 2817 yen.
Practice 1

Participation
in investment
Invest. Num.
Practice 2

Participation
in investment
Invest. Num.
Practice 3

Participation
in investment
Invest. Num.
Practice 4

Participation
in investment
Invest. Num.

You
´
¯

You
O
¯

The
Person ...
O
¯

´
¯

You
O
¯

The
Person ...
´¯

Payoff
Table

1631

Because my payoff is maximized.

PayoffTable

The Reason for Your Decision on Participation
To see whether or not the other person chooses 13 if the case ´O happens.

Your Payoff The Reason for Your Decision on Investment Number

The
Person ...
´¯

PayoffTable

7

The Reason for Your Decision on Participation
Because I want to use Payoff Table 1.

Your Payoff The Reason for Your Decision on Investment Number
500

Invest. Num.
11
Period 2 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
8Your Payoff The Reason for Your Decision on Investment Number

500

24

The Reason for Your Decision on Participation
Because I did not participate in investment at the last period.

0

Period 1 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯

Invest. Num.

Your Payoff The Reason for Your Decision on Investment Number
6117

The
Person ...
O¯

The Reason for Your Decision on Participation
To see what will happen.

13

13
You

Payoff
Table

Payoff
Table

Because this is a practice period.

The Reason for Your Decision on Participation
I chose non-participation eccentrically because this is the first period.

Your Payoff The Reason for Your Decision on Investment Number
8278
PayoffTable

The Reason for Your Decision on Participation
Because both the other person and I could obtain a large payoff.

Your Payoff The Reason for Your Decision on Investment Number
6526

Choosing 8 would be safe.

Period 3 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
6
Period 4 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.

Period 5 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 6 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
86Period 7 of the Actual Experiment
You
The
Person ...
Participation´´
in investment¯¯
Invest. Num.
Period 8 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
89Period 9 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

363

7

8

8

PayoffTable

The Reason for Your Decision on Participation
I want to earn the difference of payoff, 1700.

Your Payoff The Reason for Your Decision on Investment Number
3244
PayoffTable

The Reason for Your Decision on Participation
I chose participation safely because of my failure at the last period.

Your Payoff The Reason for Your Decision on Investment Number
2210

Because I was treated to a painful experience at the last period, I did asimilar thing.

PayoffTable

The Reason for Your Decision on Participation
I want to earn around 6000 peacefully.

Your Payoff The Reason for Your Decision on Investment Number
7345
PayoffTable

I could obtain the highest payoff peacefully.
The Reason for Your Decision on Participation
I chose participation once more, because the result at the last period wasgood.

Your Payoff The Reason for Your Decision on Investment Number
5766

Let us earn large payoffs together.

PayoffTable

The Reason for Your Decision on Participation
I chose non-participation this time because I was mad at the other personin the last period.

Your Payoff The Reason for Your Decision on Investment Number
706
PayoffTable

The Reason for Your Decision on Participation
Because of my failure at the last period. I now become composed.

Your Payoff The Reason for Your Decision on Investment Number
8225

No other choice. This is OK even if the other person chooses 6.

PayoffTable

The Reason for Your Decision on Participation
So far so good. This is safer than seeking to obtain 8278 in the case ´O.

Your Payoff The Reason for Your Decision on Investment Number
7345

The payoff I obtain by choosing 7 is smaller than that by choosing 8 if theother person chooses 6.

364Period 10 of the Actual Experiment
You
The
Person ...
ParticipationO´
in investment¯¯
Invest. Num.
7
Period 11 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 12 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
87Period 13 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

88Period 14 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.
88Period 15 of the Actual Experiment
You
The
Person ...
ParticipationOO
in investment¯¯
Invest. Num.

8

6

PayoffTable

The Reason for Your Decision on Participation
I like such a peaceful life.

Your Payoff The Reason for Your Decision on Investment Number
2210

I do not like the person who disturbs the peaceful life.

PayoffTable

The Reason for Your Decision on Participation
Take it easy. Safety first.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the reason at period 9.

PayoffTable

The Reason for Your Decision on Participation
I am tired.

Your Payoff The Reason for Your Decision on Investment Number
6526

The same as the above.

PayoffTable

The Reason for Your Decision on Participation
I wanted to avoid the painful experience.

Your Payoff The Reason for Your Decision on Investment Number
7345

The payoff I obtain by choosing 8 is larger than that by choosing 7 if theother person chooses 6. The difference is 50.

PayoffTable

The Reason for Your Decision on Participation
This is right.

Your Payoff The Reason for Your Decision on Investment Number
7345

Everybody would choose the same number.

PayoffTable

The Reason for Your Decision on Participation
Everybody would choose 8.

Your Payoff The Reason for Your Decision on Investment Number
5766

Everybody would choose 8.

365

ID Number = 20, Male, Earnings = 2817 yen.
(1) Did you understand the rules of the experiment?
1. I have understood the rules from the beginning of the experiment.
(2) Did you understand the three kinds of payoff tables?
1. I understood all three tables.
(3) Did you notice anything about the three kinds of payoff tables? Which tables did you take a look at when you decided
your investment number?
I used Payoff Tables 2 and 3 only when I wrote the record sheet. By looking at Payoff Table 1, I thought that nobody would
choose more than or equal to 12, and everybody would choose 6, 7, or 8.
(4) This question is to ask your behavior in the actual experiment. Which of the following is closest to your way of thinking
on participation and investment decisions?
1. It is desirable that my payoff is as high, regardless of the payoff of the person I am paired with.
(5) This is to ask about your participation behavior in the actual experiment. How often did you participate in investment?
3. I did not participate in investment several times, but the number of periods at which I participated in investment
was greater than the number of periods at which I did not.
The reasons for your decisions on participation:
At the early stages I thought choosing non-participation would be more profitable, and the others would scarcely choose
non-participation. However, the case in which neither participated in investment happened when I chose non-participation.
Moreover, even when I did not participate in investment, but the other person did, he made my payoff small. Therefore I
stopped choosing non-participation.
(6) How did you choose your investment number when you participated in investment?
When the person you were paired with participated in investment:
I expected everybody to choose a number between 6 and 9. I chose 8 so as to obtain a large payoff, independent of which
number between 6 and 9 the other person chooses.
When the person you were paired with did not participate in investment:
Because I was mad at the other person, I reduced his payoff to about a half of the payoff he would obtain if I chose thenumber maximizing my own payoff, with keeping my payoff reasonably large.
(7) Finally, what would be the best choice for your participation and investment? What do you think from your experiencein the experiment? Why?
Invest 8 at all periods. At first glance choosing non-participation seems to be more profitable. However, the case in which
neither participated in investment happened. Moreover, the other person chose a small number so as to make my payoffsmall, even when I did not participate in investment, but the other person did. Therefore choosing non-participation would
be less profitable than choosing participation.

366