Social memory,evidence, and conflict

This paper examines an equilibrium model of social memory — a society's vicarious beliefs about its past. We show that incorrect social memory is a key ingredient in creating and perpetuating destructive conflicts.We analyze an infinite-horizon model in which two countries face off each period in a game of conflict characterized by the possibility of mutually destructive “all out war” that yields catastrophic consequences for both sides. Each country is inhabited by a dynastic sequence of individuals. Each individual cares about future individuals in the same country, and can communicate with the next generation of their countrymen using private messages. Social memory is based on these messages, and on physical evidence — a sequence of imperfectly informative public signals of past behavior. We find that if the future is sufficiently important for all individuals, then regardless of the precision of physical evidence from the past there is an equilibrium in which the two countries engage in all out war with arbitrarily high frequency, an outcome that cannot arise in the standard repeated game. In our construction, each new generation “repeats the mistakes” of its predecessors, leading to an endless cycle of destructive behavior.Surprisingly, we find that degrading the quality of information that individuals have about current decisions may “improve” social memory. This in turn ensures that arbitrarily frequent all out wars cannot occur.     

Mandating behavioral conformity in social groups with conformist members

Social interaction among individuals with a preference for conformity gives rise to coordination externalities which are not internalized in a non-cooperative setting. Mandating behavioral conformity, by centrally imposing a common, group-wide action, internalizes these coordination externalities, but also comes at a cost of restraining individuals’ self-regarding goals. We explore a framework of social interaction among privately informed individuals with conformist preferences to examine when mandating behavioral conformity improves group welfare. Our analysis elucidates how the desirability of mandating behavioral conformity is shaped by the group's socio-economic structure. We find that mandating behavioral conformity is not desirable in social groups that are ex ante homogeneous—either with respect to members’ contribution to group welfare or their innate conformist tendency. In contrast, mandating behavioral conformity can be beneficial in those ex ante heterogeneous social groups where the individuals who contribute most to group welfare also exhibit the strongest preference for conformity.     

Impact of electoral competition,swing voters and interest groups on equilibrium policy platforms: Exploring the strategic forces at work

This paper constructs a stylized model of election between two opportunistic candidates who can influence equilibrium policy platforms in exchange for monetary contributions provided by two distinct lobby groups. Two key features are embedded which give rise to a dual uncertainty in the model: the existence of partisan spread across voter groups as well as the embezzlement of campaign funds received by the electoral candidates from the interest groups. We derive and compare the equilibrium platforms of the two office-seeking candidates in three scenarios: none of the above uncertainties exist (benchmark case), only uncertainty about voters’ preferences exist (swing-voter case), and both the uncertainties exist (swing voters and lobby groups case). We find that an opportunistic candidate’s swing-voter tax platform is always lower than the benchmark tax platform. Additionally, the equilibrium tax choice of electoral contenders in the swing voters and opposing lobby groups case is found to be greater than the tax level chosen under the swing-voter case if the lobby group advocating a greater level of tax is sufficiently well-organized such that it outweighs the relative swing-voter effect in that group. Furthermore, we find that when an electoral candidate transitions from being highly corrupt to becoming relatively more honest, the equilibrium level of public good provision adjusts in conformity with the well-organized group’s economic preferences. Finally, if the strength of relative lobbying effect is weaker, a lower partisan bias within that group induces an electoral candidate to choose a tax platform closer to that group’s policy bliss point.     

Religion,discrimination and trust across three cultures

We propose that religion impacts trust and trustworthiness in ways that depend on how individuals are socially identified and connected. Religiosity and religious affiliation may serve as markers for statistical discrimination. Further, affiliation to the same religion may enhance group identity, or affiliation irrespective of creed may lend social identity, and in turn induce taste-based discrimination. Religiosity may also relate to general prejudice. We test these hypotheses across three culturally diverse countries. Participants׳ willingness to discriminate, beliefs of how trustworthy or trusting others are, as well as actual trust and trustworthiness are measured incentive compatibly. We find that interpersonal similarity in religiosity and affiliation promote trust through beliefs of reciprocity. Religious participants also believe that those belonging to some faith are trustworthier, but invest more trust only in those of the same religion—religiosity amplifies this effect. Across non-religious categories, whereas more religious participants are more willing to discriminate, less religious participants are as likely to display group biases.     

Trust and reciprocity in inter-individual versus inter-group interactions: The effects of social influence, group dynamics, and perspective biases

Using an experimental trust game, I examine whether the perspectives and behavior of group representatives and consensus groups differ from those of the same individuals in an analogous inter-individual situation. A primary goal of this research is to extend past work on trust and reciprocity by examining the impact of the social contexts within which social interactions are characteristically embedded. Specifically, this research concerns whether norms and dynamics of trust and reciprocity differ in the contexts of inter-individual and inter-group interactions. First, I examine whether dynamics of trust and reciprocity differ in various inter-group interactions where inter-group decisions are operationalized as 1) autonomous group representatives, i.e., individuals who are given the responsibility of unilaterally making a decision on behalf of a three-person group engaging with a group representative of another such group; and 2) consensus groups, i.e., group members making a consensus trust or reciprocity decision for their groups via a collective process with another such group. Results of these studies show that 1) people trust less and reciprocate less when responsible for a group or organizational decision as autonomous group representatives; 2) consensus groups do not differ from individuals in their level of trust but show dramatically less reciprocity. The group consensus mechanism in fact produced by far the lowest reciprocity level, significantly lower than that exhibited by either individuals or autonomous group representatives. Thus, inter-group trust and reciprocity dynamics are not readily inferable from their inter-individual counterparts. Moreover, an important implication is emerging here: the extent and direction of the discrepancy between individual and group choices in regard to trust and reciprocity levels and possibly other social preferences in general may depend importantly on the precise details of the group decision-making mechanism, for example whether decisions are made consensually, by majority vote, or by a group leader or representative. In addition to examining the level of trust and reciprocity that occur in these various situations, I also studied, using both behavioral and questionnaire data, the roles of self-interest, social influence, and group dynamics in trust and reciprocity perceptions and behavior. The results showed that there exist discrepancies between behavioral forecasts and the actual behavior, and that trusting behavior is driven strongly by expectation of level of reciprocation, while reciprocating behavior is driven strongly by the difference between trust expectation and actual trust received.     

ON EQUILIBRIUM FOR OVERLAPPING GENERATIONS ORGANIZATIONS*

Necessary conditions for equilibrium are that beliefs about the behavior of other agents are rational and individuals maximize. We argue that in stationary OLG environments this implies that any future generation in the same situation as the initial generation must do as well as the initial generation did in that situation. We conclude that the existing equilibrium concepts in the literature do not satisfy this condition. We then propose an alternative equilibrium concept, organizational equilibrium that satisfies this condition. We show that equilibrium exists, it is unique, and it improves over autarky without achieving optimality. Moreover, the equilibrium can be readily found by solving a maximization program.     

Tax evasion and social interactions

The paper extends the standard tax evasion model by allowing for social interactions. In Manski's [Manski, C.F. (1993). Identification of Endogenous Social Effects: The Reflection Problem. Review of Economic Studies 60(3), 531–542.] nomenclature, our model takes into account endogenous interactions, i.e., social conformity effects, exogenous interactions, i.e., fairness effects, and correlated effects. Our model is tested using experimental data. Participants must decide how much income to report given individual and group tax rates and audit probabilities, and given a feedback on the other members' reporting behavior. Myopic and self-consistent expectations are considered in the analysis. In the latter case, the estimation is based on a two-limit simultaneous tobit with fixed group effects. A unique social equilibrium exists when the model satisfies coherency conditions. In line with Brock and Durlauf [Brock, W.A., Durlauf, S.N. (2001b). Interactions-Based Models, in J. Heckman and E. Leamer, eds., Handbook of Econometrics 5, Elsevier Science B.V., 3297–380.], the intrinsic nonlinearity between individual and group responses helps identify the model. Our results provide evidence of fairness effects but reject social conformity.     

Social norms and the fertility transition

This paper provides a norm-based explanation for two features of the fertility transition that have been observed in many different settings: the slow response to external interventions and the wide variation in the response to the same intervention. Most societies have traditionally put norms into place to regulate fertility. When the economic environment changes, individuals gradually learn through their social interactions about the new reproductive equilibrium that will emerge in their community. This characterization of the fertility transition as a process of changing social norms is applied to rural Bangladesh, where norms are organized at the level of the religious group and interactions rarely cross religious boundaries. Consistent with the view that changing social norms are driving changes in reproductive behavior in these communities, we find that the individual's contraception decision responds strongly to changes in contraceptive prevalence in her own religious group within the village whereas cross-religion effects are entirely absent. Local changes in reproductive behavior occur independently across religious groups despite the fact that all individuals in the village have access to the same family planning inputs.     

CORRELATED EQUILIBRIA,GOOD AND BAD: AN EXPERIMENTAL STUDY*

We report results from an experiment that explores the empirical validity of correlated equilibrium, an important generalization of Nash equilibrium. Specifically, we examine the conditions under which subjects playing the game of Chicken will condition their behavior on private third‐party recommendations drawn from publicly announced distributions. We find that when recommendations are given, behavior differs from both a mixed‐strategy Nash equilibrium and behavior without recommendations. In particular, subjects typically follow recommendations if and only if (1) those recommendations derive from a correlated equilibrium and (2) that correlated equilibrium is payoff‐enhancing relative to the available Nash equilibria.     

SKILL REQUIREMENTS,SEARCH FRICTIONS,AND WAGE INEQUALITY*

We analyze wage inequality, extending the Burdett and Mortensen (International Economic Review 39 (1998), 257–73) model by incorporating worker heterogeneity through skill requirements. We provide sufficient conditions for existence of an equilibrium where more productive firms offer higher wages. The unique such equilibrium is characterized in a closed form solution. Both within‐ and between‐group inequality are explicitly calculated. We then calibrate the model to explain the joint movement of both within‐ and between‐group inequality in the late 1980s and 1990s, an explanation that has been elusive in the literature so far.     

Group interaction, heterogeneity, rules, and co-operative behaviour: Evidence from a common-pool resource experiment in South Africa and Namibia

We present econometric evidence of how sociodemographic characteristics, economic background, group effects, and dynamic personal and group interactions influence the co-operative behaviour of individuals in a social dilemma situation. The data are from a framed common-pool resource experiment conducted in Namibian and South African farming communities. Our estimates suggest complex but stable social dynamics within groups over the course of the game. We conclude that group interactions may be significantly influenced by the degree of sociodemographic heterogeneity. Our study shows that the introduction of rules matters, as it improves co-operation, but that the concrete shape of such rules may be less important than the underlying social interaction.     

Dissertation abstract: Three essays on the determinants of behavior in the commons-experimental evidence from fishing communities in Colombia

This dissertation presents the results of a series of common pool experiments conducted in three regions of rural Colombia with individuals who face a social dilemma in their everyday lives that is similar to what was presented in the experiment. The research objectives are to develop an empirical characterization of how individual behavior deviates from purely self-interested Nash behavior and to further our understanding of the effects of alternative institutions to promote more conservative choices in common pool experiments.Groups of five subjects participated in a 20-period common pool resource game framed as a harvest decision from a fishery. Every group first played 10 rounds of a baseline limited access common pool resource game and then 10 additional rounds under one of five institutions: face-to-face communication, one of two external regulations, and communication combined with one of the two regulations. The two external regulations consisted of an individual harvest quota that was set at the efficient outcome, but differ with respect to the level of enforcement. A total of 420 individuals participated in the experiments, with individual earnings averaging slightly more than a day’s wages. The results are presented in three essays.The first essay, What Motivates Common Pool Resource Users?, develops and tests several models of pure Nash strategies of individuals who extract from a common pool resource when they are motivated by combinations of self-interest, altruism, reciprocity, inequity aversion or conformity. The results suggest that a model which balances self-interest with a strong preference for conformity best describes average strategies. The data are inconsistent with a model of pure self-interest, as well as models that combine self-interest with individual preferences for altruism, reciprocity and inequity aversion.The second essay, Communication and Regulation to Conserve Common Pool Resources, tests for interaction effects between formal regulations imposed on a community to conserve a local natural resource and non-binding verbal agreements to do the same. The results indicate that formal regulations and informal communication are mutually reinforcing in some instances, but this result is not robust across regions or regulations. Therefore, the hypothesis of a complementary relationship of formal and informal control of local natural resources cannot be supported in general; instead the effects are likely to be community-specific. There is some evidence to suggest that these effects are correlated with the relative importance of formal regulations versus informal community efforts in the community.The third essay, Within and Between Group Variation in Individual Strategies in Common Pools, analyzes the relative effects of groups and individuals within groups in explaining variation in individual harvest decisions for particular institutions, and uses a hierarchical linear model to examine how these sources of variation may vary across institutions. Communication serves to effectively coordinate individual strategies within groups, but these coordinated strategies vary considerably among groups. In contrast, externally-imposed regulatory schemes (as well as unregulated limited access) produce significant variation in the individual strategies within groups, but these strategies are roughly replicated across groups so that there is little between-group variation.     

Misery loves company: Social regret and social interaction effects in choices under risk and uncertainty

Extensive field evidence shows individuals? decisions in settings involving uncertainty depend on their peers? decisions. One hypothesized cause of peer group effects is social interaction effects: an individual?s utility from an action is enhanced by others taking the same action. We employ a series of controlled laboratory experiments to study the causes of peer effects in choice under uncertainty. We find strong peer group effects in the laboratory. Our design allows us to rule out social learning, social norms, group affiliation, and complementarities as possible causes for the observed peer group effects, leaving social interaction effects as the likely cause. We use a combination of theory and empirical analysis to show that preferences including “social regret” are more consistent with the data than preferences including a taste for conformity. We observe spillover effects, as observing another?s choice of one risky gamble makes all risky gambles more likely to be chosen.     

Non-Laplacian beliefs in a global game with noisy signaling

In standard global games, individual behavior is optimal if it constitutes a best response to agnostic—Laplacian—beliefs about the aggregate behavior of other agents. This paper considers a standard binary action global game augmented with noisy signaling by an informed policy-maker and shows that in this game, equilibrium beliefs depart in quite stark ways from the Laplacian benchmark. In the limit as signals become arbitrarily precise, so that all fundamental uncertainty is removed (leaving only strategic uncertainty), the equilibrium beliefs of the marginal individual concerning the aggregate action collapse to a discrete Bernoulli distribution, giving probability mass only to the polar extreme outcomes. By contrast in the underlying standard global game the marginal individual believes the aggregate action has a continuous uniform distribution, giving equal likelihood to all possible outcomes.     

Voting under ignorance of job skills of unemployed: the overtaxation bias

Usual models on voting over basic income–flat tax schedules rest on the assumption that voters know the whole distribution of skills even if at equilibrium some individuals do not work. If individuals’ productivity remains unknown until they work, it may be more convincing to assume that voters have only beliefs about the distribution of skills and that a learning process takes place. In this paper, at each period, individuals vote according to their beliefs which are updated when getting new information from the job market. The voting process converges towards some steady-state equilibrium that depends on both the true distribution of skills and the initial beliefs. The equilibrium tax rate is higher than (or equal to) the tax rate achieved in the perfect information framework. An illustration is provided on French data: if voters are over-pessimistic as to the potential productivity of unemployed people, majority voting may lock the economy in an “informational trap” with a high tax rate and a high level of inactivity.     

Stability and Segregation in Group Formation

This paper presents a model of group formation based on the assumption that individuals prefer to associate with people similar to them. It is shown that, in general, if the number of groups that can be formed is bounded, then a stable partition of the society into groups may not exist. (A partition is defined as stable if none of the individuals would prefer be in a different group than the one he is in.) However, if individuals' characteristics are one-dimensional, then a stable partition always exists. We give sufficient conditions for stable partitions to be segregating (in the sense that, for example, low-characteristic individuals are in one group and high-characteristic ones are in another) and Pareto efficient. In addition, we propose a dynamic model of individual myopic behavior describing the evolution of group formation to an eventual stable, segregating, and Pareto efficient partition. Journal of Economic Literature Classification Numbers: C72, H41.     

Mutually acceptable courses of action

We offer a game-theoretic framework that enables the analysis of situations whereby rational individuals with different beliefs and views of the world agree to a shared course of action. We introduce a new solution concept: a mutually acceptable course of action, which can be viewed as an (incomplete) contract or a social norm that free rational individuals would be willing to follow for their own diverse reasons. We show that by varying the degree of completeness of the underlying course of action, our concept can be related to commonly used solutions, such as perfect equilibrium, perfect Bayesian equilibrium, (rationalizable) self-confirming equilibrium, and rationalizable outcomes. We are grateful to the editor and an anonymous referee for very useful and helpful comments and suggestions. Earlier versions of this paper were circulated under the title “Towering over Babel: Worlds Apart but Acting Together”. We thank participants at the World Congress of Game Theory Society (2004), the International Conference on Game Theory (2004), the European Meeting (2004), and the Econometric Society World Congress (2005). Financial support from SSHRC and NSERC of Canada, and the National Science Council of Taiwan are gratefully acknowledged.     

Social motives in intergroup conflict: Group identity and perceived target of threat

We experimentally test the social motives behind individual participation in intergroup conflict by manipulating the perceived target of threat—groups or individuals—and the symmetry of conflict. We find that behavior in conflict depends on whether one is harmed by actions perpetrated by the out-group, but not on one׳s own influence on the outcome of the out-group. The perceived target of threat dramatically alters decisions to participate in conflict. When people perceive their group to be under threat, they are mobilized to do what is good for the group and contribute to the conflict. On the other hand, if people perceive to be personally under threat, they are driven to do what is good for themselves and withhold their contribution. The first phenomenon is attributed to group identity, possibly combined with a concern for social welfare. The second phenomenon is attributed to a novel victim effect. Another social motive—reciprocity—is ruled out by the data.     

Regular Distributive Efficiency and the Distributive Liberal Social Contract

We consider abstract social systems of private property, made of n individuals endowed with nonpaternalistic interdependent preferences, who interact through exchanges on competitive markets and Pareto‐improving lump‐sum transfers. The transfers follow from a distributive liberal social contract defined as a redistribution of initial endowments such that the resulting market equilibrium allocation is both: (i) a distributive optimum (i.e., is Pareto‐efficient relative to individual interdependent preferences) and (ii) unanimously weakly preferred to the initial market equilibrium. We elicit minimal conditions for meaningful social contract redistribution in this setup, namely, the weighted sums of individual interdependent utility functions, built from arbitrary positive weights, have suitable properties of nonsatiation and inequality aversion; individuals have diverging views on redistribution, in some suitable sense, at (inclusive) distributive optima; and the initial market equilibrium is not a distributive optimum. We show that the relative interior of the set of social contract allocations is then a simply connected smooth manifold of dimension n ? 1. We also show that the distributive liberal social contract rules out transfer paradoxes in Arrow–Debreu social systems. We show, finally, that the liberal social contract yields a norm of collective action for the optimal provision of any pure public good.