Most economic models are based on the self-interest hypothesis that assumes that all people are exclusively motivated by their material self-interest. In recent years experimental economists have gathered overwhelming evidence that systematically refutes the self-interest hypothesis and suggests...

We show that concerns for fairness may have dramatic consequences for the optimal provision of incentives in a moral hazard context. Incentive contracts that are optimal when there are only selfish actors become inferior when some agents are concerned about fairness. Conversely, contracts that...

Do competitive markets remove the impact of social norms and customs on market out-comes? Or are these social forces capable of exerting a persistent influence? Many economists seem to believe that social norms and customs have, if at all, only temporary effects in competitive markets. So far...

One of the outstanding results of three decades of laboratory market research is that under rather weak conditions prices and quantities in competitive experimental markets converge to the competitive equilibrium. Yet, the design of these experiments ruled out gift exchange or reciprocity...

If some of the returns to migration accrue from return migration, the optimal duration of migration may be shorter than the feasible duration of migration. We develop a model that provides and highlights conditions under which return migration takes place even though a reversal of the...

We demonstrate how altruism can flourish in a population of nonaltruists. We assume that each individual plays a one-shot prisoner's dilemma game with his or her sibling and that the probability than an individual survives to reproduce is proportional to his or her payoff in this game. We model...

We study human capital depletion and formation in an economy open to out-migration, as opposed to an economy which is closed. Under the natural assumption of asymmetric information, the enlarged opportunities and the associated different structure of incentives can give rise to a brain gain in...