Where genetically unrelated members of a group benefit from mutual adherence to a social norm, agents may obey the norm and punish its violators, even when this behavior cannot be justified in terms of self-regarding, outcome-oriented preferences. We call this strong reciprocity. We distinguish...

Monitoring by peers in work teams, credit associations, partner- ships, local commons situations, and residential neighborhoods is often an effective means of attenuating incentive problems. Most explanations of the incentives to engage in mutual monitoring rely either on small group size or on...

Networks such as ethnic credit associations, close-knit residential neighborhoods, "old boy' networks, and ethnically linked businesses play an important role in economic life but have been little studied by economists. These networks are often supported by cultural distinctions between insiders...

We propose an explanation of cooperation among unrelated members of a social group, in which providing group benefits evolves because it constitutes an honest signal of the member's quality as a mate, coalition partner or competitor, and therefore results in advantageous alliances for those...

Social capital generally refers to trust, concern for one's associates, a willingness to live by the norms of one's community and to punish those who do not. While essential to good governance, these behaviors and dispositions appear to conflict with the fundamental behavioral assumptions of...

The paper generalizes the Kiyotaki-Wright trade model by treating the trading period as a finite game, so Nash's theorem can be used to prove the existence of equilibrium, and by treating the economy as a Markov process, so an ergodic theorem can be used to show the existence of equilibria with...

Experimental behavioral scientists have found consistent deviations from the predictions of the canonical model of self-interest in over a hundred experiments from around the world. Prior research cannot determine whether this uniformity results from universal patterns of behavior, or from the...

Suppose there is a principal-agent relationship between employer and employee in which effort is not contractible, but is elicited through employer incentive mechanisms. We term preferences that allow the employer to elicit effort at lower cost incentive enhancing. We analyze how such...

How is cooperation among large numbers of unrelated individuals sustained? Cooperation generally requires altruism, where individuals take actions that are group-beneficial but personally costly. Why do selfish agents not drive out altruistic behavior? This is the puzzle of prosociality....

A number of outstanding puzzles in economics may be resolved by recognizing that where members of a group benefit from mutual adherence to a social norm, agents may obey the norm and punish its violators, even when this behavior cannot be motivated by self-regarding, outcome-oriented...