Factors affecting the creation of modern property ownership of forest commons in Japan:
An examination of historical, prefectural data

Takuya Takahashi (Corresponding author)
School of Environmental Science, The University of Shiga Prefecture2500 Hassaka, Hikone, Shiga 522-8533, Japane-mail: tak@ses.usp.ac.jp, taka.takuya@gmail.com
Koji Matsushita
Graduate School of Agriculture, Kyoto University
Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, JapanWil de Jong
Center for Integrated Area Studies, Kyoto University
46 Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501, Japan(ABSTRACT)
Forest commons in Japan are known as iriai, and they represent a century old communal
forest management arrangement. In 1966, the government of Japan enacted the Iriai
Modernization Act, which aimed to assign legal ownership to forest iriais. It gave forest users
the option to choose between individual or collective ownership. The paper explores theimplementation of the act and whether if the choices for iriai modernization and group orindividual ownership can be linked causally to characteristics of the forest user group. By theyear 2010, 36.5% of the area of forest iriais had been modernized. The size of forest iriai
user group and the ratio of plantation forest appeared negatively correlated with theconversion to modern property ownership, but the unity among user group members appeared
positively correlated with iriai modernization. The persistence of following customs andtraditions of the user group correlated with modernization towards group ownership under theact, while past labor contribution by group members appeared positively correlated withmodernization towards individual ownership. The case of forest iriai modernization in Japanis relevant for the expanding debate on the interrelations between a state’s natural resource
use reforms and how forest commons are incorporated in this process.

(Keywords)
commons; modernization; state; statistical analysis; quantitative analysis; Japan1

1. INTRODUCTION
A significant proportion of the global forests are managed as common property. When it
concerns forestlands that is controlled by communities, in which case it often concerns
common property according to customary rules, the legal status of such forestland is often
ambiguous. Much of the related academic inquiry on forest common property clarified selfgovernance, for instance on the internal mechanisms of governance of commons (e.g.
Ostrom, 1990 and 2009). More recent research has highlighted linkages with state regimes(Berkes 2002:300). This has now been addressed in major research projects, including for
instance in Asia (Yanagisawa, 2015). In this paper, we examine modernization policies offorest commons in Japan (irai), triggered by the government Iriai Modernization Act of 1966,
and we analyze implementation of this acts for a period of five decades
The term iriai refers to a natural habitat that is of shared interest to a community and held
under a customary common property arrangement. Iriais emerged since before the Edo Era(McKean and Cox, 1982), an era that lasted from the 1603 until 1867. Already since the Edoera, local governance of commons was affected by efforts of the ruling shogunate to subject
the country to a shared rule of law. After the Meiji Restoration of 1868, the newly establishedJapanese government tried to subject forest iriais to a regime that allowed including theminto tax collection schemes. Rather autonomous hamlets were during this time incorporated
into municipalities and the latter took control of forests as part of the “Public (Hamlet) Forest
Reorganization and Unification Project” which lasted from 1910 to 1939 (Handa, 1988:212).
The latest effort to adapt forest iriais to a modern public administration has been the 1966
“Act for Modernization of Iriai” (hereafter called Iriai Modernization Act or the Act). This
represents efforts of central government and prefectural governments to convert iriai forestgroups, their governing organization, and the rules under which they operate into modern
legal entities such as forest producers’ cooperatives or agricultural producers’ cooperatives(nougyouseisan houjin) who comply by the regulations that concerns them. Together withreforming collective groups as owners of former iriai forest, the policies also promoted
dividing forest iriais into privately owned woodlots.
Our paper is divided into five parts. Section 2 provides more details on the phenomenon offorest iriais and their histories. Section 3 describes the methods of the underlying research,
including a number of hypothesis that we test. Section 4 presents the results and the analysis
and the paper ends with a discussion and conclusion in section 5.
2. Background: Forest commons modernization in JapanThe Japanese forest iriais have a complex and long history. McKean and Cox (1982) describe
the tumultuous pre-Tokugawa history of Japan, which sees the decline of influence of the
Kyoto based Imperial Court over Japan’s territory, followed by a decline of influence of court
nobles and temples who had taken over control of the previous imperial and public lands overthat same territory. During this time prominent members of villages became in charge ofmanaging lands nominally still owned by feudal rulers. According to McKean and Cox’
analysis, the 16th century internal wars gave power to the rural population as warlords
dependent on their support to achieve their political objectives. This is the underlying
political process of Japan that explains why village common lands became a prominent
natural resource governance form throughout rural Japan and between the 14th and 16th
century.
Tokugawa managed to impose a strict “totalitarian administrative structure” (McKean andCox, 1982:68), which was ruthlessly enforced, but under this regime forest iriais did not lose
their independence or self-control. Some of the elements of the Tokugawa rule of law
enforcement, like for instance mechanisms to assure collective responsibility, actually wereadopted by iriai member groups. The desire of the Tokugawa government to control the2daimyos, their feudal lords who implemented the Tokugawa rules, diminished the incentives
for them to exploit villagers, and this strengthened village independence. And finally, during
the Tokugawa era a construction boom increased the demand for timber. While this demand
encouraged daimyos to control forest with high quality timber, it also led to the recognition ofcommunal rights over resources including over forest iriais (McKean and Cox, 1982).
Iriai lands played an important role in rural livelihoods until the 1950s economic recovery
after the pacific war (McKean and Cox, 1982). By 1960, the total area of iriai forests wasestimated by Nakao (1989) to be over 3 million ha. Opinions on how useful or relevant iriai
modernization have been are viewed critically by scholars (Kasahara, 1996; Noguchi, 2014).
Policy makers believed that forest iriais were underutilized, due to their legal status undercustomary iriai-type ownership; and that modern group ownership such as forest producers’
cooperatives, or as individual ownership, would improve the contributions of these commonsto economic growth and wellbeing of the rural population (Ministry of Agriculture andForestry, Department of Survey and Statistics, 1962).
The 1960 World Agriculture and Forestry Census Survey shows the status of forest iriais
after almost 100 years of industrialization of Japan. Among 109,909 forest iriais identified in
the survey, 21,920 groups (19.9%) produced forest products, such as timber and fuel woodfrom February 1959 through January 1960. A total of 11,046 groups (10.1%) produced timberand 13,145 groups (12%) produced fuel wood or charcoal; some groups produced both. Of
the 21,920 forest iriais that produced forest products, 4,901 (4.5%) distributed the products totheir members, while the remaining entities sold these products and kept the cash proceeds inthe groups’ accounts or distributed the cash proceeds among members. This also shows thatby the end of the 1950s, the majority of forest iriais members did not rely on forests tocontribute to household income or consumption. This trend has continued until today.
After several years of research and discussion among governmental bureaucrats and experts,
the Iriai Modernization Act of 1966 was approved (Handa, 1988). In Japan, since thebeginning of the Act, around 30 to 40% of the area of forest commons have been converted tomodern types of ownership such as individual private ownership, forest producers’
cooperatives, joint ownership and non-profit associations. The Act was initially conceived asa means of increasing the size of non-industrial private forest ownership by providing
additional forest lands to individual owners, as well as establishing cooperative forestry
operations managed by former commoners. One could argue that many forest producers’
cooperatives that are supposed to be modern legal entities without customary relationships,
retain many of their traditional characteristics such as contributions to community expenses
or restrictions of membership.
The consequences of the Iriai Modernization Act are thought to be two-fold. On the one
hand, modernization led to the establishment of forest production cooperatives and individualownership, which may be theoretically more suited to the for-profit production of forest
products. On the other hand, under the increasing decline of forestry activities in Japan, theirai reforms have not resulted in the vigorous for-profit forestry activities anticipated at thetime, while it does impose new burdens such as corporate tax payments and obligatory
management tasks for the members of cooperatives.
3. METHODS AND HYPOTHESES
We hypothesize that the original conditions of forest iriais likely influence theirmodernization, and the direction that modernization may take. We propose as dependent
variables indicators of modernization of forest iriais, of which there are three. 1) The total
area and numbers of iriai forests that modernized, expressed as the percentage of the total
number, and the total area of forest iriais in 1960, when the last comprehensive survey on
iriai forest in Japan was conducted. This can be disaggregated into 2) those that modernized
into consolidated group ownership, such as cooperatives, corporations or joint ownership, and
3) forest iriais that modernized into individual ownership. These modernizations were the3result of the implementation of the Iriai Modernization Act for each prefecture, and that wererecorded in public statistics (Forestry Agency, 1970-2002, 2003-2012).
We use as data the averages for prefectures of the dependent and independent variables, as
only those are available in official statistics. There is no recorded information on all iriai
forests and their modernization status until 2010. This is because public records provide data
for every year of iriai modernization for 45 prefectures, hence we could track progress of
iriai modernization between 1967 and 2010. Data for Hokkaido and Okinawa are notavailable, because forest iriais were not consistently reported. While this limitation constrains
our analysis, the information we obtained provide an important number of data points thatmake it possible to undertake a sound correlation analysis and demonstrate statisticalcorrelations between iriai modernization and the factors that we hypothesize below, which
explains modernization. We calculated the percentages of modernized forest iriais bydividing the areas of modernized forest iriais with the areas of forest iriais identified in 1960
(Ministry of Agriculture and Forestry, 1962), six years before the enactment of the Act. 1 We
used those data as our source to establish the original conditions of forest iriais (Ministry ofAgriculture and Forestry, 1962). We recorded and analyzed linkages between the original
features of forest iriais in each prefecture, and explored whether they can statistically belinked to iriai modernization. The descriptive statistics for variables related to initialconditions are given in the Appendix to the paper.
3.2 Hypotheses to be tested
Using the conceptualization of possibly causal relations between forest iriai characteristics
and modernization outcomes, we propose 12 hypotheses, which we tested with the data thatcharacterize independent and dependent variables. The hypotheses guide the kind of featuresof the forest iriais that are relevant and guided data collection. The hypotheses are numbered
H1 – H12 and text between brackets is a shorthand for the hypothesis, which is used in thetables.
H1 (Number of members per iriai): The number of members (households) of the iriai is
negatively correlated with the modernization outcome. This is because the costs ofcoordination and achieving consensus increase when the group that has shared claims
over the iriai is larger.
H2 (Iriai group larger than corresponding hamlet): Forest iriais that have a larger
number of households than the corresponding agricultural village (hamlet), are lesslikely to modernize than forest iriais where that is not the case. This is also a cost issue;
modernization of these forest iriais is more costly, than when the number of members issmaller.
H3 (Does not permit new members): Iriai member groups that do not permit new
members are more likely to go through iriai modernization. Such groups have a certain
level of cohesion that is conducive to a smooth consensus-building among its members,
which makes change easier and thus has a positive correlation with iriai
modernization. 2
1 In 1960 World Agriculture and Forestry Census Survey forest irais are identified as customary common

holdings. With regard to the data regarding group modernization and individual modernization from 1967
through 2010, only the data about areas are published. Given such data limitation, we decided to employ
the portions of areas modernized as dependent variable. We interpret the portion of areas modernized as aproxy of irai modernization in a given prefecture, with more weights for large forest commons.
2 New members might prefer modernization to maintaining the original condition; therefore, the correlation
might be just the opposite (Iriai member groups that do not permit new members are LESS likely to go
through iriai modernization.). Forest commons in Japan, however, do not usually allow new members inlarge numbers. Therefore, it is almost inconceivable to assume new members have a large say in the
management of forest commons.
4H4 (Permits members’ relatives or returning members to join the group): Groups thatallow relatives of members or old members who return from another area to rejoin thegroup are positively correlated with iriai modernization, for the same reason as underH3.
H5 (Permits new residents): Groups permitting new residents in the hamlet, once theyobtained the status of official resident, to join the group will favor modernization of thegroup. When groups adopt new residents of the hamlet, they can consolidate as forest
producers’ cooperatives, a joint ownership or non-profit associations. This represents a
confirmation and continuations of the traditional iriai organization, but with a different
name, and related changes in how the group operates.
H3 and H5 represent different situations. Where H3 concerns the categorical denial of
new membership, H5 concerns conditional permission of new membership of an irai
forest group, if the household obtains membership for the village. The membership ofan iriai forest group and village membership are two different memberships. In theoriginal survey, the questions regarding these two categories are separate questions.
H6 (Allows trading of shares): Groups permitting someone who has bought shares incommons forests to join the group is negatively correlated with modernization in theform of consolidated group ownership. This practice indicates that the commoditizationof forest lands is occurring in the community and as a result, consensus building islikely to be difficult under such conditions (McKean, 1992; pp.261-262). This, thus
inhibits progress towards modernization of the iriai. However, groups that permit
trading of shares can be expected to favor individual ownership, hence are likely tocorrelate positively with iriai cases that modernized towards individual ownership.
H7 (Households leaving the hamlet lose all rights): A wide variety existed in terms ofwhether the community would still grant rights to commons forest to households who
leave the hamlet in which the forest iriai is located. The most extreme case is thathouseholds lose all rights and will not be compensated. The opposite option is thathouseholds who leave the hamlet, maintain all their rights, which is considered under
H8. The former option represents a more traditional iriai rule. Iriai ownership and thus
membership is embedded in the community, and cannot be granted, nor maintained byhouseholds who cease to reside in the community. Between the two options, actuallyquite many variations exist and those include: some compensation is facilitated for lost
rights or shares can be sold by leaving members. H7 thus postulates that groups which
do not allow leaving members to retain any rights, or receive any compensation are
more likely to correlate positively to modernization, in the form of recognized groupownership, because these groups share a high respect for the iriai institution. The latter
will make it easier to find consensus and thus foster modernization towards groupownership (McKean, 1992).
H8 (Households leaving the hamlet retain all rights): Groups that allow departing
members to maintain their rights over forest iriais correlate negatively withmodernization towards various forms of group ownership. The rule to retain rights is anindication that the traditional iriai scheme is weakened and as a result, achieving a
consensus on adopting a modernization change is quite difficult and not likely tohappen (McKean, 1992).
H7 and H8 represent mutually exclusive cases, but that cases that are in between H7
and H8 do exist (i.e., not exhaustive). The correlation coefficient between the variable
representing H7 and the variable representing H8 is -0.646, and not -1 (see Table 7
below), which justifies retaining the two hypotheses. H7includes cases like: lose almost
all rights, but receive compensation for losing the rights; must sell rights to thecommunity; can sell rights to community right holders; can sell rights to all community5

members; can sell rights to outsiders. H8, on the other hand, represents cases whenrights are retained after leaving the community.
H9 (Group management ratio): Groups that own a certain portion of commons foreststhat is managed under the direct control of the group, rather than being separately
managed by individual members, is positively correlated with modernization towards
collective user groups. The explanation is that actual collective management enhances
the unity of the group, which facilitates consensus building, which favors
modernization under the 1966 Act.
H10 (Plantation ratio): The percentage of planted areas in forest iriais in 1960
correlates positively with modernization according to the 1966 Act, since past
investments encourage members to engage more actively in the management of forests.
H11 (Labor investment): A higher percentage of group members who themselves workin their forests correlates positively with modernization for the same reason as outlinedin H10.
H12 (Obligatory labor investment): Groups that demand their members to spend
obligatory labor on forest management correlates positively with modernization, for thesame reason as mentioned in H10. In addition, the fact that a group demands that its
members work in the forests indicates that the cohesiveness of the group is relatively
strong, which also encourages smooth consensus building, and thus modernization.
We examined the 12 hypotheses by calculating the correlation coefficients corresponding to
the respective dependent and independent variables that are entailed in each of the
hypotheses. We do not intend to find complicated relational patterns with a relatively small
number of cases from our sample (n=45). Our investigation mainly concerns the linear
relationships between variables. As an exception, we investigated the potential non-linear
influences of the sizes of the commons on modernization in the latter part of this paper.
We do not exclude that there might be other hidden factors that have influenced forest iriais
modernization, such as different policies pursued in different prefectures. However, thepolicy regarding forest commons in Japan after World War II has been led by the central
government. The law was enacted by the central government, and instructions were issued by
the central government and manuals were published by groups closely associated with thecentral government. Every year, consultants in each prefecture who cooperate withmodernization processes convene and discuss their experiences in Tokyo under the central
government’s guidance. In addition, the modernization policy had been strongly influenced
by the general policy frame of the Forestry Basic Act of 1964 and the accompanying policy
target for increasing plantations, which was a shared nationwide policy (Handa, 1988;
Matsushita, 2012). In other words, it is acceptable to assume that the policy frame of iriai
modernization was homogeneous in Japan. Assuming that the other hidden factors are
random, in this study we concentrated on the initial conditions of the forest iriais, which canbe thought of as the most influential factors in modernization. Table 1 summarizes the
hypotheses introduced here and indicates its link with iriai modernization in general andgroup ownership.

6

Table 1 Hypotheses tested in the paper.
Initial conditions (Explanatory variables)

1. No. of members in iriai
2. Iriai group larger than corresponding hamlet
3. Does not permit new members
4. Permits members' relatives or returning members
to join the group
5. Permits new residents
6. Allows trading of shares
7. Households leaving the hamlet lose rights
8. Households leaving the hamles retain rights
9. Group management ratio
10. Plantation ratio
11. Labor investment
12. Obligatory labor investment

Modernization+

Group modernization

+
+
+
-

+
+
+
+

4. DATA ANALYSIS AND RESULTS
4.1 Dependent variables
First, we examine the overall picture of modernization following the implementation of the1966 Iriai Modernization Act. Table 2 shows the trend of numbers of forest iriais thatmodernized and the areas that were affected from 1967 until 2010. During 1967 to 1975,
2.7% of the forest iriais modernized, and this constituted 18.4% of the area of all forest iriais.
Between 2001 and 2010 only 0.2% of the original number of forest iriais modernized, andthis constituted 0.9% of the original area. By the year 2010, 6.0% of the total of forest iriais
had been modernized, and this represents 36.5% of the total area that was under forest iriais
in 1960. Consequently, more than 60% of the original forest iriais maintained an organization
structure which they had before the Iriai Modernization Act.

Table 2. Numbers and areas of forest iriais modernized under the iriai Modernization Act

1967-1975
1976-1980
1981-1985
1986-1990
1991-1995
1996-2000
2001-2005
2006-2010

Number of
approved
Cumulative
Percentage
modernization
percentage
projects（Period 0）
2,997
2.7%
2.7%
Period 1
1,396
1.3%
4.0%
Period 2
1,037
0.9%
4.9%
Period 3
559
0.5%
5.4%
Period 4
283
0.3%
5.7%
Period 5
186
0.2%
5.8%
Period 6
121
0.1%
6.0%
Period 7
76
0.1%
6.0%

Approved
modernization
Percentage
projects in area(ha)
290,34518.4%
125,002
8.0%
74,041
4.7%
37,951
2.4%
19,866
1.3%
13,300
0.8%
8,312
0.5%
6,518
0.4%

Cumulative
percentage
18.4%
26.3%
31.0%
33.5%
34.7%
35.6%
36.1%
36.5%

Period 0 is for 9 years while other periods are for 5 years. In the following correlation analysis, Period 0 isfor 7 years. In this table, the data for Hokkaido prefecture are included.

Table 3 shows the composition of group and individual modernization for each period. While7both types of modernizations decline over the entire period, because total number ofmodernizations decline, by Period 3 (1986-1990) the balance between the two shifts, andindividual modernization exceeds group modernization. Table 4, with data of the 15
prefectures with the highest percentages of forest iriais that modernized between 1967 and2010, indicates that here are significant differences in modernization patters between
prefectures.
Table 3. Composition of group and individual modernization（Period 0）
Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7Group
182,401
78,21940,70018,164
8,125
5,935
2,816
1,958

%
62.8%
62.6%
55.0%
47.9%
40.9%
46.6%
33.9%
30.0%

Individuaｌ
107,944
46,77933,344
19,787
11,741
6,814
5,487
4,560

%
37.2%
37.4%
45.0%
52.1%
59.1%
53.4%
66.1%
70.0%

Table 4. Percentages of forest iriais modernized in the top 15 prefectures*#
Prefecture
Saga
Akita
Ishikawa
Miyazaki
Kochi
ShimaneFukui
Kumamoto
Oita
Niigata
Iwate
NagasakiKanagawa
Kagoshima
NaganoInitial area of Iriai (ha)6,357
54,1688,275
29,856
18,273
11,732
34,557
18,077
18,42689,49066,287
20,283
14,327
41,521
133,466

Period 0
77%
44%
24%
47%
47%
30%
43%
13%
23%
26%
22%
16%
27%
4%
17%

Period 1
20%
25%
15%
18%
15%
30%
25%
9%
15%
18%
11%
5%
4%
6%
9%

Period 2
12%
20%
7%
9%
13%
14%
6%
19%
7%
5%
7%
4%
3%
5%
5%

Period 3
11%
6%
31%
2%
4%
3%
2%
6%
5%
2%
5%
3%
0%
6%
1%

Period 4
1%
3%
8%
5%
0%
0%
0%
11%
3%
1%
3%
2%
0%
3%
0%

Period 5
2%
1%
2%
2%
3%
1%
0%
10%
0%
1%
1%
3%
1%
3%
1%

Period 6
0%
1%
2%
1%
0%
0%
0%
1%
2%
1%
0%
7%
0%
4%
0%

Period 7
0%
1%
0%
1%
1%
0%
0%
4%
2%
0%
0%
1%
2%
5%
0%

Total (1969-2010)
125%
102%
89%
84%
83%
77%
76%
74%
59%
54%
49%
41%
37%
35%
34%

*In Saga and Akita Prefectures, the percentages for the whole periods (1969-2010) exceed 100 %. Thismay be due to under-estimation of commons forests in the 1960 census survey.
#Period 0 in this Table indicates seven years from 1969 through 1975

4.2 Independent variables
We examined why in some prefectures more forest iriais modernized to a new type ofownership than in others prefectures. We calculated Pearson’s correlation coefficients
between modernization percentages and variables that might be related to modernization,using the initial, pre-Iriai Modernization Act conditions of 1960. We also examined theinterrelationships between the coefficients (Table 5). We use the modernization percentages
for each of the seven periods as well as the modernization percentage for the whole 42-year
period. The variables that we hypothesized to be related to modernization are derived fromthe twelve hypotheses explained above. After having completed these calculations, we then3
identified
thevariableswithstatisticallysignificant
coefficients.

3 Since Japan has only 45 prefectures with consistent iriai-forests statistics—a relatively small number—

we counted correlation coefficients with less than 15 % statistical significance in order to explore theexistence of relationships.
8

Table 5. Correlation coefficients from analyses
2. Iriai grouplarger thancorrespondi
ng hamlet

3. Does not
permit new
members

4. Permits
members'
relatives orreturningmembers tojoin thegroup

5. Permits
newresidents

6. Allows
trading ofshares7.
Households
leaving thehamlets lose
rights8.
Households
leaving thehamlets
retain rights

9. Groupmanagement
ratio

PeriodNo. of approvals

0
1
2
3
4
5
6
7
Whole

0.008
0.026
0.051
0.049
0.105
0.112
-0.0370.146
0.037-0.0280.017
0.036-0.021
0.096
0.067-0.044-0.004
0.006

0.072
0.080
0.132
0.195
0.228 0.326 **
0.114
0.147
0.123

0.182
0.120
0.015
0.069
-0.007-0.008
0.053
0.102
0.112

-0.016-0.003-0.017-0.146-0.163-0.282 *-0.077-0.178-0.045

0.018
0.020
0.045
0.159
0.151
0.113
0.119
0.134
0.052

-0.026-0.021-0.076-0.208-0.244 -0.334 **-0.136-0.229 -0.081-0.111-0.103-0.091-0.073-0.0080.138-0.0240.111-0.091-0.130-0.031-0.050
0.089
0.116
0.216
0.158
0.038
-0.045-0.190-0.227 -0.179-0.186-0.192-0.129-0.215-0.022-0.208

0.031
0.088
0.161
0.192
0.302 **
0.346 **
0.225 0.404 ***
0.127

0.121
0.152
0.204
0.310 **
0.388 ***
0.469 ***
0.321 **
0.441 ***
0.209

Areas approved

0
1
2
3
4
5
6
7
Whole

-0.196-0.250 *-0.215-0.197-0.097-0.106-0.104-0.045-0.253 *-0.062-0.173-0.039-0.383 ***-0.114-0.076-0.096-0.034-0.163-0.087-0.1600.047-0.213-0.053
0.038
0.025
0.093
-0.1100.169
0.260 *
0.030
0.078
-0.017-0.018
0.048
0.063
0.174

0.099
0.136
0.018
0.244 0.038-0.044-0.083-0.1440.121

0.001-0.0100.082-0.0530.109
0.031
0.230 0.126
0.027

0.056
0.129
-0.0700.128-0.064-0.123-0.060-0.1370.052-0.099-0.135-0.030-0.165-0.0220.153-0.0230.137-0.107-0.128-0.124-0.180-0.060-0.093-0.0820.219 -0.039-0.142-0.117-0.205-0.102-0.0690.032
0.075-0.0780.080-0.135-0.024-0.0160.129-0.029
0.207
0.167
0.143
0.318 **
0.042

0.064
0.090
0.229 0.058
0.260 *
0.217
0.209
0.350 **
0.156

Group modernization(Areas)

0
1
2
3
4
5
6
7
Whole

-0.163-0.210-0.211-0.208-0.046-0.032-0.0980.009-0.214-0.128-0.239 -0.089-0.384 ***-0.272 *-0.070-0.0450.081-0.216-0.188-0.227 -0.049-0.260 *-0.280 *-0.014-0.0730.092-0.221 -0.300 **
0.319 **
0.200
0.117
0.279 *
0.085
0.011
-0.0450.312 **

0.197
0.178
0.150
0.288 *
0.297 *
0.052
0.053
-0.1270.230 -

-0.081-0.069-0.029-0.057-0.069-0.1070.092
0.174-0.0750.219 0.207
0.131
0.218 0.250 *
0.002
0.038
-0.0010.238 -

-0.193-0.180-0.149-0.250 *-0.283 *0.107-0.099-0.002-0.222 --0.132-0.089-0.114-0.1150.003
0.025
0.466 ***
-0.142-0.118-0.185-0.266 *-0.242 -0.082-0.1700.004-0.0660.123-0.229 --0.066-0.085-0.002-0.104-0.089-0.0310.100
0.238 -0.071

0.020
0.030
0.081
-0.025-0.029-0.067
0.074
0.181
0.031

Individual modernization(Areas)

0
1
2
3
4
5
6
7
Whole

-0.160-0.169-0.140-0.159-0.091-0.095-0.071-0.051-0.191

0.049
0.035
0.016
-0.333 **-0.039-0.054-0.070-0.072-0.032

0.078
0.041
0.105
-0.134
0.030
0.052
0.083
0.057
0.066

-0.0680.015-0.1160.027-0.105-0.0590.034
0.086-0.060-0.066-0.011-0.0930.163-0.052-0.071-0.145-0.095-0.057

0.106
0.090
0.140
-0.0410.140
0.077
0.232 0.054
0.134-0.177-0.071-0.2040.014-0.148-0.137-0.116-0.144-0.185

0.063
0.016
0.075
-0.050
0.064
0.126
0.030
0.145
0.071

-0.070-0.108-0.1670.007-0.102-0.100-0.0030.022-0.109

0.019
0.013
0.046
-0.0460.087
0.085-0.054
0.029
0.031

0.040
0.104
0.185
0.055
0.252 *
0.187
0.120
0.229 0.154

0.095
0.135
0.263 *
0.141
0.291 *
0.249 *
0.213
0.289 *
0.235 -

- 15％ siginificance, * 10％ significance, ** 5％ significance, ***Period 0 represents the period between 1969 and 1975

10.
Plantation
ratio

12.
Obligatorylaborinvestment

Indicators of modernization

1. No. of
members iniriai

11. Labor
investment

1％ significance9

4.3 Testing of hypotheses
Table 6 uses the results of the correlation analyses from Table 5 to validate or reject the 12
hypotheses proposed in section 2.
Table 6. Correlation analysis and hypotheses
Initial conditions (Explanatory variables)

Modernization
Hypotheses

1. No. of members in iriai
2. Iriai group larger than corresponding hamlet
3. Does not permit new members+

No. of signs
+
2
0
0
5
2
4

+

5

4. Permits members' relatives or returning members
to join the group
5. Permits new residents
6. Allows trading of shares
7. Households leaving the hamlet lose rights
8. Households leaving the hamlet retain rights
9. Group management ratio
10. Plantation ratio
11. Labor investment
12. Obligatory labor investment

+
+
+
+

Group modernization
No. of signs
Hypotheses
+

0

2
0
8
13

+
+
-

0
4
0
0

3
0
4
0

0
0
0
3

A majority of the hypotheses were supported by the analysis, with the signs of their coefficients
corresponding with the predictions of the hypotheses. A few of the hypotheses, however, were
not validated with the findings. We interpreted these unanticipated results, however, as statisticalproperties of the explanatory factors, rather than as adequate proof of the need to reject theoriginal hypotheses. The correlation coefficients that relate to H3 (Does not permit new
members), includes four negative coefficients that are statistically significant, while two positivecoefficients are significant. Table 7 shows that H3 (Does not permit new members) is negatively
correlated with H5 (Permits new residents) and H7 (Households leaving the hamlets loses right).
We believe that these negative correlations might be the result of anomalies, rather thanreflecting causal linkages. Partial correlation coefficients were calculated among variables 3, 5
and 7, and the variables for group modernization in Period 1, 3, 4 and the whole duration. The
negative correlation between variable 3 and the variable for group modernization in Period 4
turned out to be statistically not-significant.
Table 7. Correlation matrix among explanatory variables (initial conditions)
4. Permits
members'
2. Iriai group
1. No. of
3. Does not relatives or 5. Permits
larger thanmembers inpermit new returning
newcorresponding
iriai
members
members to residents
hamletjoin thegroup

6. Allows
trading ofshares7.
8.
10.
Household Households 9. Groups leavingleaving the management Plantation
ratio
ratio
the hamlet hamlet
lose rights retain rights

11. Labor
investment

12.
Obligatorylaborinvestment

1. No. of members in iriai
2. Iriai group larger than corresponding hamlet
3. Does not permit new members

1.000
0.461
-0.181

0.461
1.000
0.284

-0.181
0.284
1.000

0.051
-0.366-0.5380.154-0.236-0.865-0.062
0.030
0.379

0.169
-0.239-0.871-0.235
0.216
0.653

0.159
0.060
0.076

0.088
-0.0440.093-0.100-0.0790.553-0.145-0.1480.528

4. Permits members' relatives or returning members tojoin the group

0.051-0.366-0.538

1.000

0.413

-0.3050.515-0.430-0.098-0.184-0.319-0.2405. Permits new residents
6. Allows trading of shares

0.154-0.062-0.2360.030-0.8650.379

0.413-0.3051.000-0.615-0.6151.000

0.936-0.591-0.612-0.052-0.0660.026-0.1690.322-0.5550.487-0.5340.494

7. Households leaving the hamlet lose rights

0.169-0.239-0.871

0.515

0.936

-0.5911.000-0.646-0.082-0.165-0.578-0.546

8. Households leaving the hamlet retain rights
9. Group management ratio
10. Plantation ratio
11. Labor investment
12. Obligatory labor investment-0.2350.159
0.088-0.100-0.1450.216
0.060-0.044-0.079-0.148

0.653
0.076
0.093
0.553
0.528

-0.430-0.098-0.184-0.319-0.240-0.612-0.066-0.169-0.555-0.534-0.052
0.026
0.322
0.487
0.494

-0.646-0.082-0.165-0.578-0.546

1.000
0.058
0.146
0.324
0.225

0.058
1.000
0.020
0.212
0.205

0.146
0.020
1.000
0.396
0.177

0.324
0.212
0.396
1.000
0.907

0.225
0.205
0.177
0.907
1.000

10

These findings, augmented by the above statistical explanations of the apparent contradictions,generally support our hypotheses, except for H3. The ease of consensus building has encouraged
modernization under the Iriai Modernization Act (H1, H2, and H9). But consensus building isinversely correlated with the size of iriai forest groups and the direct management of the forest
area by individual group members. The cohesiveness of iriai forest groups also encouraged
modernization (H4 and H9). The strength of traditional customs related to forest iriais has led togroup-type modernization, rather than to individual-type modernization (H5, H7, and H8). Past
investments in forest iriais have also led to active modernization (H11 and H12), especiallyindividual ownership.
While a majority of the hypotheses were supported by the findings, H6 and H10 were not.
Tentative alternative hypotheses are in order for the two unsupported hypotheses. With regard tocorrelation coefficients related to H6 (Allows trading of shares), no coefficient was statisticallysignificant. This suggests that many groups that allow trading of shares might have pursued
individual-type modernization under the Iriai Modernization Act. With regard to H10, the higher
the plantation ratio, the more difficult the modernization appeared to be, is contrary to what the
hypothesis postulates. This may be related to differences in policy efforts by prefectural
governments. Because the original rationale for modernization was the lower plantation ratio
among forest iriais, which is a reflection of low intensity of forest management, prefectures with
forest iriais with high plantation ratios may not have aggressively pursued the modernization of
their forest commons.
We tried to investigate further the relationship between the size of groups involved in forest iriais
and progress in modernization. We found negative relationships between group-size andmodernization (H1 and H2). However, as suggested by Handa (2006), the relationship might be a
non-linear, inverse-U shape type, because the balance of costs and benefits for commoners mightchange due to economies of scale and congestion phenomena. Table 8 shows the correlation
coefficients between group sizes and modernization processes. The group sizes were represented
by the percentages of groups with certain numbers of households. It was found that groupmodernization is enhanced when group sizes are relatively small, i.e. around 11 members, whilegroup modernization is difficult with groups sizes of more than or equal to 301 members.
Table 8. Relationship between group sizes and modernization processes
No. of approved projects
Areas of approved projects>=11 HH
0.159
0.118

Group modernization

0.229

Individual modernization-0.062>= 31HH

0.129-0.050->= 51HH

0.109-0.129>= 101HH

0.033-0.2490.107-0.008-0.177-0.211-0.215-0.228>= 151HH>= 201HH*-0.175-0.216-0.222--0.179-0.124-0.033-0.102-0.215>= 301HH

0.071-0.2190.145-0.166>= 501HH

0.094-0.175--0.259*-0.004">= 11 HH" indicates the percentage of gourps own Iriai commons forests with more than or equal to 11 households.
- 15％ siginificance, * 10％ significance, ** 5％ significance, *** 1％ significanceWe also investigated dynamic aspects of the correlations found in the calculations summarized
above. We divided the eight periods into four first-half periods (periods 0 to 3) and four secondhalf periods (periods 4 to 7) and again counted the statistically significant positive and negative
correlation coefficients. Table 9 shows the results of this analysis. We identified twelve pairs ofstatistically significant coefficients for the first half and second half periods. Among them, fivepairs indicate increases (shown by double underlines), six pairs indicate decreases (single
underlines), and one pair indicates no-change (no underline). It would be quite natural to expect
the initial conditions of forest iriais to lose influence in later years. Contrary to this expectation,
however, it appears that in several instances the influences lasted for more than 20 years, i.e.
during four periods. In particular, labor investments in forest iriais display strong relationships
with modernization development even after more than 20 years.
11

Table 9. First half and second half comparison
Modernization

Initial conditions (Explanatory variables)

Hypotheses

No. of signs[(1st half)/(2nd half)]

1. No. of members in iriai-+
02. Iriai group larger than corresponding hamlet-

03. Does not permit new members+

4. Permits members' relatives or returning members
to join the group

2
[0/2]

1
[1/0]
5
[4/1]
3
[2/1]

+

4

0

[3/1]

Group modernization
Hypotheses

5. Permits new residents+

6. Allows trading of shares-

7. Households leaving the hamlet lose rights+

8. Households leaving the hamlet retain rights-

9. Group management ratio+

10. Plantation ratio

+

+

-

2
[1/1]
0

0

3
[3/0]
0

0

0
0
2
[0/2]

3
[3/0]
0

8
[0/8]
12. Obligatory labor investment
+
12
0
[3/9]
* The numbers of significant positive or negative signs do not match the ones found in the previous analysis
since the signs for the whole period are excluded in the current analysis.
** [0/0] is omitted for the sake of simplicity.
11. Labor investment

+

2
[0/2]
0

No. of signs[(1st half)/(2nd half)]

5. DISCUSSION AND CONCLUSION
We examined modernization policies of forest commons in Japan, triggered by the Iriai
Modernization Act of 1966, and analyzed outcomes of these policies for a period of five decades.
Our main focus in this paper was on the factors that influenced the outcomes of themodernization policies.
The case of iriai modernization in Japan is relevant in the discussion on how the state deals with
forest commons. The discussion is relatively new in the literature, but rapidly expanding (e.g.
Yanagisawa, 2015). Rather than a somewhat narrow view that states mostly aim to privatize
forest commons, recent evidence shows that in many cases states had more open attitudes toward
forest commons. However, a common phenomenon is that where states themselves modernized,
and revised land and land use policies, and forest policies, they also sought to incorporate and12accommodate forest commons, including their legal status, but often also their inner governanceworkings, to modern legislation and public administration.
The relevance of this paper in that debate is that responses of individual forest common user tomodernization policies may vary and that the variation can be causally linked to thecharacteristic of the forest common user group, or their own internal governance. As we saw inthe case of forest iriais of Japan. The Iriai Modernization Act allowed the option of continuing tooperate as a modernized forest common, or to divide up the forest land into private plots. We
detected that forest iriais with certain characteristics chose the option of continuing as a forest
common, while those with different characteristics chose to privatize.
These findings, we argue, have important policy implications, for Japan, and for policies towards
forest commons more in general. First, targeting is important. Modernization policies orintervention policies toward forest commons are likely to have a differentiated outcome. In thecase of Japan, key features that influence response are: size of the groups, persistence offollowing customs and traditions, and the trajectory of labor investment. This strongly suggests,
that policies may target certain types of forest commons, or that different options should be
included in the policies for forest commons with different characteristics.
We also reflect on forest iriais of Japan, and appropriate policies for these culturally still very
relevant forest organizations. An important reality of modern Japan’s forest sector is its relative
low profitability. This questions the relevance of modernization policies that are still including
options as private ownership or forest iriais being modernized into forest producer cooperatives,because the latter have as their main reason of being to make profits. In contemporary Japan,
commoners, in general, have little interest in forest management that emphasizes timber
production due to its low profitability. Rather, options should be explored that forest iriais canprovide other functions, for example, for recreation or education purposes. If such a change offunctions can be established and forest iriai user groups can be mobilized to engage in delivering
these functions, they can regain commitment for their iriai and this may revitalize the forest
iriais of Japan as a vital modern forest management unit, with clear social function, but
continuing and keeping alive an age old tradition.
Lastly, we briefly discuss the limitations of the study and the possibilities for further research
related to this topic. First, this study used a limited and a relatively small number of samples, i.e.,
45 prefectures in Japan. This has as a consequence that the statistical relevance of our analysis israther weak. A new data source, for example, individual forest iriai level data, would strengthen
the statistical relevance of the research and the conclusions. Data on modernization policies orintervention policies in other countries might give us new insights into the research questions
addressed in this study. Second, this study infers causal relationships from correlations. Causal
tracking of individual cases of commons forests would provide a more detailed and nuanced
explanation of correlations. Since the majority of modernization projects in Japan took place inthe 1960s and 1970s, many participants, including commoners and government officials, are now
advanced in age. Interviews with forest iriai user groups, which is necessary to reconstruct theprocesses of modernization, should be conducted as soon as possible. Third, our study did not yet
explore other factors that may have influenced the adoption of the modernization projects bycommoners. For instance, we assumed that policy frameworks had been relatively homogenous
all over Japan or varied randomly, ignoring differences among prefectural governments in termsof modernization efforts. In addition, we did not yet consider the wider economic portfolio of
hamlets that held a forest iriai, i.e. the relevance of agricultural activities or income from nonagricultural jobs. Those became common during Japan’s industrialization period, and may haveinfluenced the modernization processes of forest iriais. We also did not examine how
modernization policies affected the performance of forest management, production outputs orinvestments in commons forests. The data for recent years presented above suggest that themodernization process has lost its momentum, and practitioners as well as some researchers have13

called for a reform of the modernization policies (e.g., Kasahara, 1996 and 2000). Comparisons
between modernized and non-modernized forest iriais could provide us with an insight into
whether state intervention is desirable, and under what conditions. Further research on theconsequences of the modernization policy is waiting to be undertaken.
(Acknowledgement)This work was supported by JSPS KAKENHI Grant Numbers 24510055 and 15H02871. We
would appreciate various comments and suggestions during conferences such as SEEPS2014 in
Tokyo and IASC2015 in Edmonton.

14

REFERENCES
Berkes, Fikret (2002) Cross-scale institutional linkages: perspectives from the bottom up. In
National Research Council (2002) The Drama of the Commons, Washington D.C.: National
Academy Press, pp. 293-321.
Diez, Thomas, Nives Dolshak, Elinor Ostrom, and Paul C. Stern (2002) The Drama of theCommons. In National Research Council (2002) The Drama of the Commons, Washington D.C.:
National Academy Press, pp. 3-35.
Forestry Agency (ed.) (1970-2002) Ringyou Toukei Youran (Forestry Statistics Summary).
Tokyo: Rin’ya Kousaikai.
Forestry Agency (ed.) (2003-2012) Sinrin Ringyou Toukei Youran (Forest and Forestry Statistics
Summary). Tokyo: Nihon Sinrin Ringyou Sinkoukai.
Handa, Ryoichi (1988) Policy for the administration of public forests and common forests. In
Handa, Ryoichi (ed.) (1988) forest Policy in Japan. Tokyo: Nihon Ringyo Chosakai, pp.211-225.
Handa, Ryoichi (2006) iriai groups/self-governing bodies, and the commons(iriaisyuudan/zitisosiki, sosite komonzu), Nakanihon iriai Rin’ya Kenkyuukai Kaihou, No.26,
pp.6-22.
Kasahara, Rokurou (1996) iriai policy should change its course (Tenkan wo semarareru
iriairin’ya seisaku). Nakanihon iriai Rin’ya Kenkyuukai Kaihou, No.16, pp.1-2.
Kasahara, Rokurou (2000) Examining iriai policy from the standpoint of foerstry (Ringyou kara
mita iriairin’ya kindaika seisaku). Nakanihon iriai Rin’ya Kenkyuukai Kaihou, No.20, pp.9-13.
Matsushita, K. (2012) Recent Problems and New Directions for Forest Producer Cooperatives
Established in Common Forests in Japan, In Julio, J. Diez ed., Sustainable forest Management –Case Studies, Rijeca: InTech, pp.161-182.
McKean, Margaret A. (1992) Success on the commons: a comparative examination of
institutions for common property resource management. Journal of Theoretical Politics, 4(3),pp.247-281.
McKean, Margaret A. and Thomas R. Cox (1982) The Japanese Experience with Scarcity:
Management of Traditional Common Lands. Environmental Review 6(3) 63-91.
Ministry of Agriculture and Forestry, Department of Survey and Statistics (ed.) (1962) 1960-nen
Sekai Nouringyou Sensasu Ringyou Tyousahoukokusyo Kankoukyouyuuhen (The 1960 World
Agriculture and Forestry Census Survey, Report on Forestry, Customary Commons Forests),
Tokyo: Norin Tokei Kyokai
Nakao, H. 1989. Ownership and utilization before and after the modernization of right in iriai
forests. In: M. Takei et al. (eds.) The right on Iriai forest and fields, 31-48. Tokyo: Inchiryu Sha.
Noguchi, Toshikuni (2014) A review and prospect of modernization policy of iriai foersts (iriai
rin’ya kindaika seisaku no soukatsu to tenbou). iriai Rin’ya Kenkyuu, No.34, pp.5-8.
Ostrom, Elinor (1990) Governing the Commons: The Evolution of Institutions for Collective
Action. Cambridge, UK: Cambridge University Press.
15

Ostrom, Elinor (2009) Design Principles of Robust Property-Rights Institutions: What Have We
Learned? In K. Gregory Ingram and Yu-Hung Hong (eds.) (2009) Property Rights and Land
Policies, Cambridge, MA: Lincoln Institute of Land Policy.
Yanagisawa, Haruka (ed.) (2015) Community, commons and natural resource management in
Asia. US Press: Singapore.

16

Appendix Descriptive statistics of variables for initial conditions (n=45)
Average

Minimum

MaximumStandard Deviation

1. No. of members in iriai
2. Iriai group larger than corresponding hamlet
3. Does not permit new members

67.2050.190
0.288

42.3290.057
0.130

114.694
0.363
0.489

14.6780.058
0.084

4. Permits members' relatives or returning members to join the
group

0.111

0.038

0.211

0.046

9. Group management ratio

0.399
0.141
0.575
0.199
0.485

0.185
0.053
0.282
0.077
0.344

0.606
0.255
0.776
0.427
0.835

0.101
0.046
0.115
0.063
0.094

10. Plantation ratio

0.365

0.060

0.791

0.176

11. Labor investment

0.487

0.232

0.680

0.095

12. Obligatory labor investment

0.341

0.106

0.533

0.092

0.795
0.496
0.320
0.149
0.089
0.061
0.036
0.017

0.670
0.372
0.200
0.075
0.032
0.020
0.008
0.003

0.932
0.658
0.458
0.262
0.166
0.130
0.094
0.050

0.056
0.062
0.055
0.041
0.031
0.025
0.017
0.009

5. Permits new residents
6. Allows trading of shares
7. Households leaving the hamlet lose rights
8. Households leaving the hamlet retain rights

Ratios of groups with certain numbers of households>=11 HH>= 31HH>= 51HH>= 101HH>= 151HH>= 201HH>= 301HH>= 501HH

17