adapting contract theory to fit contract farming this article discusses the current state of contract theory and its usefulness for conceptualizing issues related to agricultural contracting i will discuss the limitations of existing theory for applied work and what methodological improvements are needed to enhance the usefulness of the theory to agricultural economists one pervasive problem is that the canonical economic literature on contracts is rather fragmented and the various methodological strands are narrow in their focus as such there is a need for agricultural economists to engage in methodological research to develop applied contracting models that can capture higher order features of real world agricultural contracts while delivering generalizable comparative statics predictions the need for such research is obvious as contracting continues to expand along the entire modern food marketing channel in the latter part of this article i develop a simple model to illustrate how classic methodological approaches can be combined with recent developments in contract and game theory to construct applied theory models that are useful for capturing some important features of agricultural contracts

learning to trust in indefinitely repeated games abstract although it is well known that trust and trustworthiness i e the fulfillment of trust are important behaviors for the fulfillment of incomplete contracts less is known about how the economic environment influences them in this paper we design an experiment to examine how exogenously determined stochastic past relationship lengths affect trust and trustworthiness in new relationships we find that shorter lasting relationships have an immediate negative impact on both behaviors in the relationships that immediately follow while longer lasting relationships have the opposite effect the effect of stochastic end points declines for trustworthiness but not for trust as subjects gain experience indicating that trust is able to rebound when longer lasting relationships follow shorter lasting ones

punishment strategies in repeated games evidence from experimental markets abstract an experiment is designed to provide a snapshot of the strategies used by players in a repeated price competition game with a random continuation rule one hundred pairs of subjects played the game over the internet with subjects having a few days to make their decisions in each round occasionally subjects are asked to enter one period ahead pricing strategies instead of prices according to the elicited strategies between 90 and 95 of subjects punish less harshly in their initial response to a deviation than implied by the grim trigger strategy and do so in a way that depends on the size of the other subject s deviation future earnings are highest for subjects adopting the tit for tat strategy even after controlling for a subject s past earnings punishment strategies are generally softer and more graduated than implied by a grim trigger strategy and do better as a result

monopoly insurance under adverse selection when agents differ in risk aversion abstract this paper considers a profit maximizing monopolistic insurer who offers insurance to two types of risk averse agents in an environment where the uninsured position has the same distribution across types agents utility functions are private information and types are independently and identically distributed we prove that if there is no lower bound on liability and the types differ markedly in their attitudes to heavy losses the insurer can extract almost all rent by offering full insurance to agents who are more risk averse and two valued partial insurance to the others under limited liability separating insurance contracts have a similar structure but it may be impossible to approximate the first best unless the uninsured position is supported by two atoms insurance is provided to all agents journal of economic literature classification numbers d42 d82

an experimental study of finitely and infinitely repeated linear public goods games abstract a growing literature in experimental economics examines the conditions under which cooperation can be sustained in social dilemma settings in particular several recent studies contrast cooperation levels in games in which the number of decision rounds is probabilistic to games in which the number of decision rounds is finite we contribute to this literature by contrasting the evolution of cooperation in probabilistically and finitely repeated linear voluntary contribution public goods games vcm consistent with past results ceteris paribus cooperation is found to increase in the marginal value of the public good additionally as the number of decision sequences increases there is a pronounced decrease in cooperation in the final round of finite sequences compared to those with a probabilistic end round we do not however find consistent evidence that overall cooperation rates are affected by whether the number of decision rounds is finite or determined probabilistically

umbrella branding with imperfect observability and moral hazard abstract in a framework of repeated purchase experience goods with seller s moral hazard and imperfect monitoring umbrella branding may improve the terms of the implicit contract between seller and buyers whereby the seller invests in quality and buyers pay a high price in some cases umbrella branding leads to a softer punishment of product failure which increases the seller s value in other cases umbrella branding leads to a harsher punishment of product failure which allows for a reputational equilibrium that would otherwise be impossible on the negative side under umbrella branding one bad signal may kill two revenue streams not one combining costs and benefits i determine the set of parameter values such that umbrella branding is an optimal strategy

partners or rivals strategies for the iterated prisoner s dilemma within the class of memory one strategies for the iterated prisoner s dilemma we characterize partner strategies competitive strategies and zero determinant strategies if a player uses a partner strategy both players can fairly share the social optimum but a co player preferring an unfair solution will be penalized by obtaining a reduced payoff a player using a competitive strategy never obtains less than the co player a player using a zero determinant strategy unilaterally enforces a linear relation between the two players payoffs these properties hold for every strategy used by the co player whether memory one or not

evolution and information in a gift giving game abstract we examine the stochastic stability of a process of learning and evolution in a gift giving game overlapping generations of players are randomly matched to play the game they may consult information systems to learn about the past behavior of their opponents if the value of the gift is smaller than twice the cost then gifts are not given if the value of the gift is more than four times the cost then gifts are exchanged moreover in the stochastically stable equilibrium a unique information system is selected to support cooperation journal of economic literature classification numbers c62 c72 d83

financing the provision of global public goods this paper examines the concept of global public goods gpgs and in that context explores the extent of aid oda presently being diverted to gpg provision and whether such diversion skews aid flows towards some recipients and whether diverting aid to gpg provision crowds out aid for conventional development activities these are examined on the basis of oecd data for the late 1990s the main argument of this paper is that oda should not be used for financing gpg provision by developing countries instead it is suggested that other sources of financing the provision of gpgs should be developed keeping in view the various technologies by which the gpgs can be produced and design principles for supra national institutions various arguments from sandler barrett and kanbur are considered in particular kanbur s suggestion of two tensions involving the principles of economies of scale subsidiarity economies of scope and specialization is explored further some examples of issues where a gpg is produced as a joint product of actions by national governments are considered by looking at data on eight different indicators for 1995 problems in using the joint product approach to gpg provision are also discussed

cooperative strategies in anonymous economies an experiment we study cooperation in economies of indefinite duration participants faced a sequence of prisoner s dilemmas with anonymous opponents we identify and characterize the strategies employed at the individual level we report that i grim trigger does not describe well individual play and there is wide heterogeneity in strategies ii systematic defection does not crowd out systematic cooperation iii coordination on cooperative strategies does not improve with experience we discuss alternative methodologies and implications for theory

social surplus determines cooperation rates in the one shot prisoner s dilemma abstract we provide evidence on how cooperation rates vary across payoff parameters in the prisoner s dilemma pd using four one shot games that differ only in the payoffs from mutual cooperation in our experiment participants play only the pd game and play the game once and only once so there are no potential confounds or methodological issues our results show that higher monetary payoffs from cooperation are associated with substantially higher cooperation rates which increase monotonically from 23 to 60 participants beliefs about cooperation rates track closely actual cooperation rates higher cooperation is expected from others when mutual cooperation payoffs are higher this is true also for participants who in a follow up experiment only make guesses about the choices of others

perfect and imperfect strangers in social dilemmas abstract this paper focuses on social dilemma games in which players may or may not meet the same partner again in the future a novel prisoner s dilemma experiment a meta analysis of public goods experiments and a meta analysis of previous prisoner s dilemma experiments document high cooperation rates if the likelihood to meet the same partner again in the future is high

fines leniency and rewards in antitrust this article reports results from an experiment studying how fines leniency and rewards for whistleblowers affect cartel formation and prices antitrust without leniency reduces cartel formation but increases cartel prices subjects use costly fines as punishments leniency improves antitrust by strengthening deterrence but stabilizes surviving cartels subjects appear to anticipate the lower postconviction prices after reports leniency with rewards prices fall at the competitive level overall our results suggest a strong cartel deterrence potential for well run leniency and reward schemes these findings may also be relevant for similar white collar organized crimes such as corruption and fraud

a classification of factors influencing participation in collusive tendering agreements the morality of tendering practices is an issue of economic and social significance especially when large government contracts are involved criticisms are mostly concentrated around collusive tendering illegal agreements between tenderers that result in seemingly competitive bids price fixing or market distribution schemes that circumvent the spirit of free competition and defraud clients although collusion has been identified as an endemic malaise of tendering its behavioural and moral dimensions have not been systematically studied before the paper addresses this knowledge gap and describes part of an exploratory empirical investigation of the decision making patterns utilised by estimators in australia slargest construction organisations

costs of maintaining a cartel the costs of operating a cartel are determined by the effort spent on policing member firms and errors in detection of cheaters an output review is modeled that may be used with tr igger pricing in the presence of a wiener process to describe distur bances in demand the cartel uses trigger pricing first and then swit ches to an output review costs generated by cartel maintenance affec t social welfare and provide a foundation for analyzing the impact of a cartel on society copyright 1987 by blackwell publishing ltd

can violence harm cooperation experimental evidence abstract in this paper we argue that natural resource conservation is jeopardised by the ability of users to resort to violence to appropriate resources when they become scarce we provide evidence from a lab experiment that participants interacting in a dynamic game of common pool resource extraction reduce their cooperation on efficient levels of resource extraction when given the possibility to appropriate the resource at some cost i e through conflict theoretically cooperation is achievable via the threat of punishment strategies which stop being subgame perfect in the presence of conflict accordingly we argue that the observed reduction of cooperation in the game s early stages in the lab is a consequence of participants correctly anticipating the use of appropriation when resources become scarce

theories of cartel stability and the joint executive committee this article reexamines the experience of the joint executive committee an 1880s railroad cartel to assess the applicability of the green and porter 1984 and rotemberg and saloner 1986 theories of price wars after discussing necessary modifications to the theories i estimate a number of dynamic models to explore the causes of price wars the cyclical nature of pricing and the possibility that secret price cuts may have been given the estimates provide some support for the predictions of the first theory

learning and risk aversion we study how learning shapes behavior towards risk when individuals are not assumed to know or to have beliefs about probability distributions in any period the behavior change induced by learning is assumed to depend on the action chosen and the payoff obtained we characterize learning processes that in expected value increase the probability of choosing the safest actions and provide sufficient conditions for them to converge to the choices of risk averse expected utility maximizers we provide a learning theoretic motivation for long run risk choices such as those in expected utility theory with known payoff distributions

reviewing proposals for a world environmental organisation since the earth summit in rio 1992 several calls have been made for a world environmental organisation weo and only during the last year in the run up to rio 10 five more have been added in

the evolutionary stability of cooperation is cooperation without central authority stable if so how robust is it despite what might be the conventional wisdom the evolution of cooperation did not solve this problem deductively in fact results obtained later by others seem to have contradicted the book s main message reexamining this exceptionally influential work yields a new picture part of axelrod s evolutionary story turns out to be false but the main intuition that retaliatory strategies of conditional cooperation are somehow advantaged proves correct in one specific and significant sense under a standard evolutionary dynamic these strategies require the minimal frequency to stabilize hence they support the most robust evolutionary equilibrium the easiest to reach and retain moreover the less efficient a strategy the larger is its minimal stabilizing frequency hobbesian strategies of pure defection are the least robust our main theorems hold for a large class of games that pose diverse cooperation problems prisoner s dilemma chicken stag hunt and many others

group formation and cooperation in social dilemmas a survey and meta analytic evidence abstract we survey the growing literature on group formation in the context of three types of social dilemma games public goods games common pool resources and the prisoner s dilemma the 62 surveyed papers study the effect of different sorting mechanisms endogenous endogenous with the option to play the game and exogenous on cooperation rates our survey shows that cooperators are highly sensitive to the presence of free riders independently of the sorting mechanism we complement the survey with a meta analysis showing no difference in terms of cooperation between studies implementing an endogenous and exogenous sorting what is more we find that it is no more likely for a cooperator to be matched with like minded partners in endogenously formed groups than in exogenously formed groups these observations are related as we show in the survey the success of a sorting method in matching like minded individuals and the levels of cooperation are closely interlinked

a continuous dilemma we study prisoners dilemmas played in continuous time with flow payoffs accumulated over 60 seconds in most cases the median rate of mutual cooperation is about 90 percent control sessions with repeated matchings over eight subperiods achieve less than half as much cooperation and cooperation rates approach zero in one shot sessions in follow up sessions with a variable number of subperiods cooperation rates increase nearly linearly as the grid size decreases and with one second subperiods they approach continuous levels our data support a strand of theory that explains how capacity to respond rapidly stabilizes cooperation and destabilizes defection in the prisoner s dilemma jel c72 c78 c91

an experimental test of the efficacy of a simple reputation mechanism to solve social dilemmas abstract the evolution of cooperation has been the focus of intense research in the social sciences natural sciences especially biology and even computer science it has long been recognized that the possibility of future consequences is crucial to the emergence of rational cooperation it was thought that random matching was isomorphic to one shot play but kandori 1992 showed that a reputation labeling mechanism can be used to support cooperation in the random matching prisoner dilemma we designed an experiment to test this result we found that while the level of cooperation steadily declined without a reputation mechanism with our color coded reputation mechanism the level of cooperation steadily increased with experience an econometric mixture model consisting of four reputation conditioned strategies as well as a level 0 type was fitted to the data we cannot reject the hypothesis that the majority of subjects used one of these strategies and learned with experience

pricing strategies in supergames with capacity constraints some evidence from the u s portland cement industry abstract theory demonstrates that demand variations can have nonmonotonic effects on pricing in supergames with capacity constraints furthermore this nonmonotonic relationship can be a function of capacity utilization rates time series data from 25 regional cement markets are used to examine this results empirically no statistically significant relationship is found between demand variations pricing and excess capacity

the power of the purse and its implications for bureaucratic policy making a dilemma of the power of the purse is thatcutting an agency s budget may make a desired policyinfeasible i examine the implications of thisdilemma with a repeated game in which a bureau choosesunobservable policies after a legislature sets itsbudget the bureau is work averse and has its ownpolicy preferences and therefore may cheat but thelegislature may perform an audit to recover slack funds a main result is that if the legislaturedesires a higher policy level than the agency then itfaces a trade off between good but wasteful policiesand bad but efficient ones

better later than never an experiment on bargaining under adverse selection a central result in the literature on bargaining with asymmetric information is that the uninformed party buyer can screen the informed party seller over time screening eliminates trade failures that are otherwise common in the presence of adverse selection but the downside of the bargaining institution is the cost associated with repeated offers and time frictions this article reports an experimental test of these predictions we find that rates of trade are substantially higher in the bargaining institution than in control treatments in which we remove the possibility to make repeated offers take it or leave it offer or the time frictions however we also observe a persistent overdelay before agreements are reached that is bargaining takes longer than theoretically predicted this lowers efficiency below its predicted level and below the level observed in the take it or leave it offer institution we identify possible channels for overdelay in the form of fairness preferences and loss aversion concluding that there are important behavioral deviations from the standard model that are detrimental to the efficiency of bargaining under incomplete information

cartel stability in an exhaustible resource model a simple oligopolistic common pool exhaustible resource game is considered by analysing punishment strategies including optimal punishments it is possible to determine which cartel agreements are implementable in a non cooperative play of the game joint profit maximizing allocations are sustainable for sufficiently low discounting but in general it is shown that no folk theorem exists for this model in particular for sufficiently high elasticities of demand it is shown that optimal punishments are not sufficiently severe to enforce most stationary symmetric extraction paths thus confirming the hypothesis that sufficient market power is needed for a cartel to be stable a simple common property exhaustible resource model in a discrete time infinite horizon framework will be considered by looking at punishments levelled against firms that deviate from an implicitly agreed extraction path it is possible to examine the extent to which different allocations can be supported as non cooperative equilibria we shall pay particular attention to the question of whether punishments can be severe enough to sustain implicit agreements that maximize joint profits and to the idea pindyck 1979 that cartel stability depends crucially upon market power this non cooperative approach to the question of cartel stability has been used by porter 1983 in a repeated oligopoly model with imperfect information see also green and porter 1984 while we assume perfect observability here the model is compli cated by the existence of a state variable in the form of the resource stock moreover we shall apply the idea of optimal punishments in this dynamic model abreu et al 1986 1990 have looked at general properties of the equilibrium set in the green porter model what we find is that by considering a more general strategy space than that conventionally studied cooperative extraction rates are sustainable in equilibrium for low enough discount rates in contrast to the over extraction results often obtained moreover in this model the predictions concerning the range of possible sustainable equilibria as the discount rate approaches zero are sharp while the cooperative solution belongs to the set of equilibria for low discount rates constant symmetric extraction paths below the maximum possible rate fail to be sustainable in the limit if the elasticity of demand is sufficiently high thus for low discount rates only extraction rates close to the cooperative rate are sustainable together with disagreement equilibria which involve very high extraction rates these results are in sharp contrast to those obtained from repeated games where in the limit the range of equilibria is very large the difference is explained by the existence of a state variable in the form of a declining stock of the resource these results are also in contrast to what can happen in our model when the demand elasticity is lower all constant symmetric extraction paths may be sustainable for low enough

the evolution of cooperation through imitation we study evolutionarily stable outcomes for a class of games that admit cooperation and conflict as possible nash equilibria we make use of two ideas existing strategies are more likely to be imitated than new strategies are to be introduced players are able to identify opponents behavior prior to interaction the long run evolutionary limit is efficient for the case of perfect recognition of opponents behavior for the case of imperfect recognition efficiency is not achieved and long run outcomes are more efficient the more accurate is the information strategies that emerge in the long run are those where players reward opponents who are likely to play the same way and punish opponents who are likely to play differently

optimal cartel trigger price strategies abstract a dynamical model of industry equilibrium is described in which a cartel deters deviations from collusive output levels by threatening to produce at cournot quantities for a period of fixed duration whenever the market price falls below some trigger price in this model firms can observe only their own production level and a common market price the market demand curve is assumed to have a stochastic component so that an unexpectedly low price may signal either deviations from collusive output levels or a downward demand shock

observations on cooperation we study environments in which agents are randomly matched to play a prisoner s dilemma and each player observes a few of the partner s past actions against previous opponents we depart from the existing related literature by allowing a small fraction of the population to be commitment types the presence of committed agents destabilizes previously proposed mechanisms for sustaining cooperation we present a novel intuitive combination of strategies that sustains cooperation in various environments moreover we show that under an additional assumption of stationarity this combination of strategies is essentially the unique mechanism to support full cooperation and it is robust to various perturbations finally we extend the results to a setup in which agents also observe actions played by past opponents against the current partner and we characterize which observation structure is optimal for sustaining cooperation

advantageous selection in insurance markets this article reverses the standard conclusion that asymmetric information plus competition results in insufficient insurance provision risk tolerant individuals take few precautions and are disinclined to insure but they are drawn into a pooling equilibrium by the low premiums created by the presence of safer more risk averse types taxing insurance drives out the reckless clients allowing a strict pareto gain this result depends on administrative costs in processing claims and issuing policies as does the novel finding of a pure strategy partial pooling subgame perfect nash equilibrium in the insurance market copyright 2001 by the rand corporation

the cyclical behavior of strategic inventories this paper presents a model in which inventories are used by a duopoly to deter deviations from an implicitly collusive arrangement higher inventories allow firms to punish cheaters more strongly and can thus help to maintain collusion we show that when demand is high the incentive to deviate increases so that increases in inventories may be optimal for the duopoly this rationalizes the observed positive correlation between inventories and sales in our empirical section we show that as our model predicts this correlation is more important in concentrated industries we also provide several examples where inventories have been a factor in cartel behavior

recent advances in oligopoly theory from a game theory perspective abstract this paper surveys the contribution that recent developments in game theory have made to the understanding of oligopoly theory it is argued that conventional models suffer from the problem that there are a number of solution concepts offered with little guidance as to which should be selected and this is related to the static nature of the models employed one important development in game theory has been the analysis of repeated games and when applied to oligopoly theory this suggests that outcomes may be more cooperative than conventional theory suggests related to this is the requirement that firms employ credible threats to punish cheating from cooperative outcomes and the paper examines the extent to which imperfect information may restrict the scope of firms to employ such punishments one way in which firms may seek to make threats credible is through strategic investments for example in production capacity and the paper explores how competition over price or output is integrated with competition over instruments for strategic investment

the folk theorem with imperfect public information the authors study repeated games in which players observe a public outcome that imperfectly signals the actions played they provide conditions guaranteeing that any feasible individually rational payoff vector of the stage game can arise as a perfect equilibrium of the repeated game with sufficiently little discounting the central condition requires that there exist action profiles with the property that for any two players no two deviations one by either player give rise to the same probability distribution over public outcomes the results apply to principal agent partnership oligopoly and mechanism design models and to one shot games with transferable utilities copyright 1994 by the econometric society

termination clauses in partnerships abstract we show that when designing a partnership agreement partner firms may prefer not to specify how to allocate the commonly owned assets should there be an early termination of the contract by not including such a clause firms induce litigation before a court with positive probability firms create this ex post inefficiency in order to increase the levels of non contractible investments i e increase the ex ante efficiency the absence of an asset allocation clause works as a discipline device that mitigates the hold up problem within the partnership in our set up no other contract but that without an asset allocation clause can credibly create an ex post inefficiency

repeated partnerships with multiple equilibria and imperfect monitoring an experimental study abstract i investigate finitely repeated partnership games with imperfect monitoring where both mutual effort and mutual shirking are nash equilibria of the stage game the treatment variable is the number of repetitions i find that period 1 effort rates are increasing in the number of repetitions but subjects use trigger strategies that switch to permanent shirking after enough failed projects so effort rates decrease across time in all treatments additionally the rate of decrease is less when there are more repetitions total effort does not vary much across the treatments because the increased period 1 effort when the number of repetitions is large is mostly canceled out by the erosion of effort as the game progresses

cooperation among strangers under the shadow of the future we study the emergence of norms of cooperation in experimental economies populated by strangers interacting indefinitely can these economies achieve full efficiency even without formal enforcement institutions which institutions for monitoring and enforcement facilitate cooperation finally what classes of strategies do subjects employ we find that first cooperation can be sustained even in anonymous settings second some type of monitoring and punishment institutions significantly promote cooperation and third subjects mostly employ strategies that are selective in punishment

should we have a wto for international migration the international movement of labour remains much more restricted than movement of goods or capital and the worldwide economic gains to liberalizing migration are large this paper asks whether those gains could be realized through better international cooperation on migration along the lines of the wto for trade although public opinion is marginally more negative towards the liberalization of migration than of trade the key impediment is the lack of a basis for reciprocity in negotiations over migration and this is because migration is largely driven by absolute advantage rather than by comparative advantage as in the case of trade consequently there is no basis for wto style negotiations over migration and therefore no grounds for reforming the international architecture in the hope of fostering liberalization timothy j hatton

cooperation but no reciprocity individual strategies in the repeated prisoner s dilemma a recent advance in our understanding of repeated pds is the detection of a threshold d at which laboratory subjects start to cooperate predictively this threshold is substantially above the classic threshold existence of grim equilibrium and has been characterized axiomatically by blonski ockenfels and spagnolo 2011 bos in this paper i derive its behavioral foundations first i show that the threshold is equivalent to existence of a semi grim equilibrium s cc s cd s dc s dd it is cooperative s cc 0 5 non reciprocal s cd s dc and robust to imperfect monitoring belief free next i show that the no reciprocity condition s cd s dc also follows from robustness to random utility perturbations logit equilibrium finally i re analyze strategies in four recent experiments and find that the majority of subjects indeed plays semi grim when it is an equilibrium strategy which explains d s predictive success

on the perils of stabilizing prices when agents are learning abstract the main advantage of price level stabilization compared with inflation stabilization rests on the central bank s ability to shape expectations we show that stabilizing prices is no longer optimal when the central bank can shape expectations of agents with incomplete knowledge who have to learn about the policy implemented disinflating in the short run more than agents expect generates short term gains without triggering an abrupt loss of confidence because agents update expectations sluggishly following this policy in the long run the central bank loses the ability to shape agents beliefs and the economy converges to a rational expectations equilibrium in which policy does not stabilize prices economic volatility is high and agents suffer the corresponding welfare losses however these losses are outweighed by short term gains from the learning phase

endogenous reputation formation under the shadow of the future recent research has shown that making people s decisions known to others may enhance cooperation in infinitely repeated prisoner s dilemma games with random matching this paper experimentally studies whether people can cooperate with each other by endogenously showing their identities and building cooperative reputations when there is an option to hide the identities our experiment shows that a non negligible fraction of subjects choose to conceal their identities and accordingly subjects fail to cooperate with each other in communities if hiding is cost free however almost all subjects disclose their identities and successfully achieve cooperation if a cost is charged for the act of hiding this finding has a broad methodological implication for the study of reputation mechanisms when infinitely repeated games are used in an experiment as people s behavior may be determined by their ability to hide identities

advance production inventories and market power an experimental investigation i introduction bertrand edgeworth games are an important part of any industrial organization economist s toolkit the unilateral market power created by capacity constraints represents one of economists primary methods for modeling supra competitive prices as a static equilibrium outcome in a price setting game 1 the standard bertrand edgeworth model however rather restrictively assumes that production is to demand and that goods are immediately perishable in the broad swath of modern economies that includes the production and sale of physical products these assumptions are often not even approximately satisfied goods are routinely produced prior to being offered for sale at retail establishments similarly while the effective shelf life of many products is quite short relatively few products perish immediately and many have effective shelf lives that extend throughout a sales season if not longer this paper reports a laboratory experiment conducted to assess the effects of having sellers make production decisions in advance rather than to demand and allowing sellers to carry unsold units across periods on market power in a bertrand edgeworth pricing game by way of preview we find that both advance production and an inventory option prominently affect market outcomes advance production reduces profits relative to a baseline condition while an inventory option reduces both prices and profits these results are important as they suggest that deviations from the standard oligopoly structures that routinely arise in natural contexts may fundamentally affect market performance we organize the paper as follows following a brief review of the pertinent literature in section ii we outline equilibrium predictions for baseline advance production and inventory treatments in section iii section iv describes the experimental design and procedures and section v presents the experimental results the paper concludes with a short section vi ii background a theoretical literature economists have long recognized the restrictiveness of the standard price setting oligopoly models shubik 1955 for example argues that when evaluating price setting duopolies economists should consider price quantity games where sellers simultaneously post prices and quantities in addition to games where price is the only decision variable 2 levitan and shubik 1978 compute the mixed strategy equilibrium for a duopoly given advance production and unlimited capacities more recently tasnadi 2004 analyzes the case of advance production for capacity constrained duopolists pertinent to the present investigation tasnadi shows that under very general conditions advance production raises prices but leaves seller profits unaffected the only theoretical work that analyzes the links between product durability and market prices of which we are aware is a stream of literature following coase 1972 regarding the effects of product durability on monopoly power specifically given sufficiently patient consumers the coase conjecture suggests that infinite durability will eliminate monopoly power analytical results are driven by consumers who drive prices down by waiting for future discounts 3 to the best of our knowledge no one has analyzed the effects of product durability on production and pricing incentives for capacity constrained price setting duopolists b experimental literature the relevant experimental literature consists of three strands a first strand consists of a series of papers establishing that laboratory sellers recognize and exercise the unilateral market power induced by capacity constraints pertinent seminal references are davis and holt 1994 and kruse et al 1994 while some relevant related papers include davis holt and villamil 2002 davis and wilson 2000 and wilson 1998 a second strand of the experimental literature studies the effects of advance production on posted price markets

equilibria in a stochastic resource management game under imperfect information abstract the paper considers equilibrium solutions in a stochastic resource management game the countries choose frequently between cooperative and noncooperative retaliation modes of play the choices between cooperative and noncooperative subgames are based on imperfect estimates of the fishing efforts fleet sizes of the co harvesting country during the previous period if either of the countries concludes that the fishing activity of the co harvesting country has been too intensive during the previous period i e the estimated fishing effort exceeds a trigger value then either a noncooperative retaliation period follows or cooperation is continued after a noncooperative period the countries begin to cooperate once again it is shown that equilibria in which cooperative and noncooperative periods alternate can occur in dynamic games different types of equilibria for the game exist the countries may be able to sustain efficient cooperation all the time they may oscillate between cooperation and noncooperation or they may fail to cooperate at all conditions under which an equilibrium coincides with a pareto optimal solution are studied

the graph of prisoners dilemma supergame payoffs as a function of the discount factor abstract the set of subgame perfect correlated equilibrium of the infinitely repeated discounted prisoners dilemma depends on the discount factor the graph of the correspondence of these equilibrium payoffs versus the discount factor is derived and presented these results are especially applicable to situations in which there is a random chance of the supergame ending or an exogenous probability of cooperative breakdown

constructing strategies in the indefinitely repeated prisoner s dilemma game abstract we propose a new approach for running lab experiments on indefinitely repeated games with high continuation probability this approach has two main advantages first it allows us to run multiple long repeated games per session second it allows us to incorporate the strategy method with minimal restrictions on the set of pure strategies that can be implemented this gives us insight into what happens in long repeated games and into the types of strategies that subjects construct we report results obtained from the indefinitely repeated prisoner s dilemma with a continuation probability of 95 we find that during such long repeated prisoner s dilemma games cooperation drops from the first period of a supergame to the last period of a supergame when analyzing strategies we find that subjects rely on strategies similar to those found in the literature on shorter repeated games specifically tit for tat grim trigger and always defect however we also identify features of strategies that depend on more than just the previous period that are responsible for the drop in cooperation within supergames but that may be overlooked when using the common strategy frequency estimation approach

investing to cooperate theory and experiment we study theoretically and in a lab experiment investment decisions in environments where property rights are absent in our setting a player chooses an investment level before interacting repeatedly with a given set of agents the investment stochastically affects the payoffs of the game in every subsequent period we show that more volatile returns make investment more difficult in the absence of legal protection and might force the investor to invest more to guarantee cooperation experimental results are broadly consistent with the theoretical findings

tacit collusion under interest rate fluctuations previous literature has shown that demand fluctuations affect the scope for tacit collusion i study whether discount factor fluctuations can have similar effects i find that collusion depends not only on the level of the discount factor but also and more surprisingly on its volatility collusive prices and profits increase with a higher discount factor level but decrease with its volatility these results have important implications for empirical studies of collusive pricing the role that collusive pricing may play in economic cycles and the study of cooperation in repeated games

collusion as public monitoring becomes noisy experimental evidence this paper uses laboratory experiments to test the implications of the theory of repeated games on equilibrium payoffs and estimate strategies in an infinitely repeated prisoners dilemma game with imperfect public monitoring we find that subjects payoffs i decrease as noise increases and ii are lower than the theoretical maximum for low noise but exceed it for high noise under the assumption that the subjects strategy uses thresholds on the public signal for transition between cooperation and punishment states we find that the best fitting strategy simply compares the most recent public signal against a single threshold

flexibility and reputation in repeated prisoner s dilemma games we study how three matching institutions differing in how relationships are dissolved affect cooperation in a repeated prisoner s dilemma and how cooperation rates are affected by the presence of

optimal cartel equilibria with imperfect monitoring abstract there exist optimal symmetric equilibria in the green porter model 4 8 having an elementary intertemporal structure such an equilibrium is described entirely by two subsets of price space and two quantities the only production levels used by firms in any contingency the central technique employed in the analysis is the reduction of the repeated game to a family of static games

cartel enforcement with uncertainty about costs what cartel agreements are possible when firms have private information about production costs in order for a cartel agreement to work it must take into account the incentives for firms to misrepresent their cost information and it must provide sufficient reward so that no firm wishes to defect for private cost uncertainty we characterize the set of cartel agreements with side payments that can be supported as bayesian nash equilibria we show that if defection results in either cournot or bertrand competition the incentive problems in large cartels are severe enough to prevent the cartel from achieving the monopoly outcome in contrast with common cost uncertainty the incentive problems become less severe in large cartels allowing perfect collusion

the timing of sales this paper presents a model of intertemporal price discrimination a fixed number of sellers produce a homogeneous good consumers with different preferences enter the market in each period and leave when they make a purchase the sellers typically vary their prices over time charging a high price in most periods but occasionally cutting the price to sell to a large group of customers with a low reservation price in some equilibria all stores lower their price at the same time and to the same level

reply on comment to small firms and the merger mania research on performance differences between small and large firms is booming it emerges relatively separated from the mainstream industrial organization literature inspired by levy s comment on an earlier paper we try to bridge the gap between the two areas especially we screen non cooperative game theoretical models for predictions on performance differences most of them forecast higher profits for larger firms but there exist also some models which predict the opposite for very specific circumstances

extraction of surplus under adverse selection the case of insurance markets abstract we consider a principal agent setting with two types of risk averse agents with different abilities to avoid losses abilities types are characterized by two distributions f and g which are agents private information all agents have the same increasing and strictly concave utility function u under which g has a higher certainty equivalent in this environment we derive a characterization of pairs of distributions under which a first best outcome can be achieved or approximated we prove that a first best outcome can be achieved if and only if the distribution f is not absolutely continuous with respect to the distribution g if this condition is not satisfied the first best outcome can be approximated arbitrarily close if and only if the likelihood ratio df dg is unbounded journal of economic literature classification number d82

cooperation in the finitely repeated prisoner s dilemma more than half a century after the first experiment on the finitely repeated prisoner s dilemma evidence on whether cooperation decreases with experience as suggested by backward induction remains inconclusive this paper provides a meta analysis of prior experimental research and reports the results of a new experiment to elucidate how cooperation varies with the environment in this canonical game we describe forces that affect initial play formation of cooperation and unraveling breakdown of cooperation first contrary to the backward induction prediction the parameters of the repeated game have a significant effect on initial cooperation we identify how these parameters impact the value of cooperation as captured by the size of the basin of attraction of always defect to account for an important part of this effect second despite these initial differences the evolution of behavior is consistent with the unraveling logic of backward induction for all parameter combinations importantly despite the seemingly contradictory results across studies this paper establishes a systematic pattern of behavior subjects converge to use threshold strategies that conditionally cooperate until a threshold round and conditional on establishing cooperation the first defection round moves earlier with experience simulation results generated from a learning model estimated at the subject level provide insights into the long term dynamics and the forces that slow down the unraveling of cooperation

collusion among asymmetric firms the case of different discount factors abstract this study investigates collusive behavior among asymmetric firms for this purpose we develop a selection criterion for deriving a unique collusive outcome and apply it to the case when firms have different discount factors our analysis reveals that for collusion to be self enforcing it is unnecessary that all firms have sufficiently high discount factors but rather only that firms on average have a sufficiently long run view the optimal collusive outcome entails a strict ordering of output quotas in which firms with relatively low discount factors receive a disproportionate share of market demand as found in the case of a common discount factor a fall in a firm s discount factor reduces the likelihood of successful collusion this effect reduces firm profits on the other hand in the event that firms can collude a lowering of a firm s discount factor increases its output quota so that its profits rise

an example of a repeated partnership game with discounting and with uniformly inefficient equilibria in this note we present an example of a repeated partnership game with imperfect monitoring in which all supergame equilibria with positive discount rates are bounded away from full efficiency uniformly in the discount rate provided the latter is strictly positive on the other hand if the players do not discount the future then every efficient one period payoff vector that dominates the one period equilibrium payoff vector can be attained by an equilibrium of the repeated game thus the correspondence that maps the players discount rate into the corresponding set of repeated game equilibrium payoff vectors is discontinuous at the point at which the discount rate is zero

price leadership and unequal market sharing collusion in experimental markets abstract we consider experimental markets of repeated homogeneous price setting duopolies we investigate the effect on collusion of sequential versus simultaneous price setting we also examine the effect on collusion of changes in the size of each subject s market share in case both subjects set the same price our results show that sequential price setting compared with simultaneous price setting facilitates collusion if subjects have equal market shares or if the follower has the larger market share with sequential price setting we find more collusion if subjects have equal market shares rather than unequal market shares we observe more collusion if the follower has the larger market share than if the follower has the smaller market share

learning about learning in games through experimental control of strategic interdependence we report experiments in which humans repeatedly play one of two games against a computer program that follows either a reinforcement learning or an experience weighted attraction algorithm our experiments show these learning algorithms detect exploitable opportunities more sensitively than humans also learning algorithms respond to detected payo increasing opportunities systematically however the responses are too weak to improve the algorithms payos human play against various decision maker types doesn t vary signicantly these factors lead to a strong linear relationship between the humans and algorithms action choice proportions that is suggestive of the algorithm s best response correspondence these properties are revealed only by our human versus computer experiments and not by our standard human versus human experiments nor our model simulations jel classication c72 c92 c81

is there a free rider problem in lobbying endogenous tariffs trigger strategies and the number of firms there are two reasons we expect moreconcentrated industries to have advantages over less concentrated industries in playing the lobbying game one is that in a noncooperative setting as the number firms rises we expect the free rider problem to become worse this is the finding of rodrik 1986 the second is that we expect that the ability to maintain a cooperative outcome deteriorates as the number of firms in the industry rises the classic reference is mancur olson 1965 also see russell hardin 1982 and todd sandler 1992 among others in contrast with the second intuition this paper shows that there is no general presumption that maintaining cooperation becomes more difficult as the number of firms in the industry rises the ability of an industry to overcome the free rider problem is analyzed in a re peated tariff lobbying game where cooperation may be maintained through the use of a simple trigger strategy 2 the difficulty of maintaining cooperation is measured by the critical value of the discount parameter all values above this critical value are consistent with cooperation and all values below the critical value imply that cheating will prevent maintenance of the cooperative outcome there is no presumption that this critical value rises with the number of firms a separate but related question involves asymptotic results standard intuition suggests that as industry structure approaches perfect competition it becomes impossible to maintain cooperation in the context of this paper this intuition corresponds to the critical value of the discount factor converging to i as the number of firms increases to infinity in the general case it is shown that the critical value of the discount parameter converges to a value less than 1 in the limit as the number of firms becomes arbitrarily large if the actual discount parameter lies above this value then cooperation may be maintained even with an infinite number of firms though the framework here is quite simple it provides results which contrast sharply to our standard intuition about how industry structure affects the ability to maintain cooperation there are two ways to interpret the results of this paper one is to assert that standard intuition is wrong and that there is in fact no presumption that maintaining cooperation becomes more difficult as the number

the evolution of cooperation in infinitely repeated games experimental evidence 1 for example in infinitely repeated prisoner s dilemma games with patient agents both cooperate and defect may be played in equilibrium even though the theory of infinitely repeated games has been used to explain cooperation in a variety of environments no definitive solution has been provided to the problem of equilibrium selection when both cooperation and defection are possible equilibrium outcomes which one should we expect to prevail previous experimental evidence has shown that subjects often fail to coordinate on a specific equilibrium when they play a small number of infinitely repeated games some subjects attempt to establish cooperative agreements while others defect but how would behavior evolve as subjects learn from previous repeated games would cooperation prevail when it can be supported in equilibrium or will subjects learn

how economic rewards affect cooperation reconsidered abstract recent studies suggest that payoffs in cents compared to dollars produce less defection in a repeated prisoner s dilemma game we are unable to replicate these findings with conventional economic procedures or in a direct replication

amicable divorce dissolving a partnership with simple mechanisms abstract this paper considers mechanisms for allocating the assets of a dissolving partnership that can be specified without information on the distribution of valuations of the asset or the level of risk aversion of the participants for the case of a single asset and risk averse agents three simple mechanisms are considered these mechanisms can be ranked in terms of ex post efficiency and partially ranked in terms of interim expected utility the efficiency of the alternating selection mechanism is considered for environments when there are many items to be allocated agents are risk neutral and transfers are prohibited conditions are given when a myopic strategy of picking the most preferred abailable item forms an equilibrium and these conditions are satisfied under independence under the further assumption of identical distributions of valuations it is shown that the total expected efficiency loss is at most 1 2 of the maximal value of a single item regardless of how many items are to be allocated

new directions for modelling strategic behavior game theoretic models of communication coordination and cooperation in economic relationships author s crawford vp abstract in this paper i discuss the state of progress in applications of game theory in economics and try to identify possible future developments that are likely to yield further progress to keep the topic manageable i focus on a canonical economic problem that is inherently game theoretic that of fostering efficient coordination and cooperation in relationships with particular attention to the role of communication i begin with an overview of noncooperative game theory s principal model of behavior nash equilibrium i next discuss the alternative thinking and learning rationales for how real world actors might reach equilibrium decisions i then review how nash equilibrium has been used to model coordination communication and cooperation in relationships and discuss possible developments

at will relationships how an option to walk away affects cooperation and efficiency abstract we theoretically and experimentally examine the effects from adding a simple empirically relevant action to a repeated partnership the option to walk away manipulating both the value of the outside option and its relative distribution among the partners we examine the behavior of human subjects in a repeated prisoners dilemma in particular we examine the degree of cooperation and the form of punishments used our findings indicate that cooperation rates are broadly unaffected by the value of the common outside option but that the selection of supporting punishments in relationship defections or walking away are dictated by individual rationality in contrast to the symmetric results when outside options for partners are asymmetric we find stark selection effects over cooperation with the potential for very high and very low efficiency dependent on the precise division rule

environmental risks and bank liability abstract many governments have introduced or are considering introducing laws to recover from the liable parties the cleanup costs caused by pollution damages in particular the banks who finance the firms causing environmental damages may be considered liable in various court cases in the us and elsewhere banks have been found liable while they have been exempted in others we develop a model in which the insurance sector may insure the firm for the pollution risk and the bank may lend money for investment under complete information of the bank about the firm s activities the limited liability of the firm induces excessive investment and insufficient care but full liability of the bank creates the appropriate internalization of the environmental risk this rationalization of the laws on lender liability must be qualified because in general the banks suffer from agency problems adverse selection and moral hazard in their relationships with firms in the adverse selection case full liability of the bank leads to underinvestment partial liability is better but may fail to implement the optimal second best allocation in the case of moral hazard full responsibility is killing the project too often while still leading to low care too often partial responsibility may achieve the second best optimal allocation but in some cases the level of responsibility necessary to induce the proper level of care is too high for the project to be financed by the bank we conclude with a discussion of the implications of our results with regards to liability laws for environmental damages

cartel stability and product differentiation abstract this paper employs a supergame theoretic model of collusion to analyze the effects of different levels of product differentiation on cartel stability in contrast to earlier work the ability of the parties to reach an agreement is assumed here the focus is on how greater product homogeneity increases both the gain to cheating on a collusive agreement and the magnitude of the punishments that follow a defection the total effect on the likelihood a cartel is stable is therefore unclear two particular differentiated products models are then used to demonstrate that contrary to the conventional view greater homogeneity can reduce cartel stability