A large number of individuals are randomly matched into groups, where each group plays a finite symmetric game. Individuals breed true. The expected number of surviving offspring depends on own material payoff, but may also, due to cooperative breeding and/or reproductive competition, depend on...

We study the long-run behavior of an economy where agents who are heterogeneous with respect to risk attitudes can either earn a certain income or enter a risky rent seeking contest. In contrast with standard evolutionary game theory, we distinguish between utility and material payoffs, and...

We study a simple model of the job market, where workers are assigned to employers. We specify conditions under which the market is hierarchical in a natural sense. For such hierarchies, we can state explicit values for the earnings in the worker-optimal and employer-optimal solutions. This is a...

We consider Bayesian incentive compatible and individually rational mechanisms for resolving conflicts between two agents who are uncertain about each other's fighting potential. We model the default option of outright conflict as a probabilistic contest. Examples of such contests may be...

Guilt averse individuals experience a utility loss if they believe they let someone down. In particular, generosity depends on what the donor believes that the recipient expects to receive. In experimental work, several authors have identified a positive correlation between such second-order...

This paper surveys the literature on group selection. I describe the early contributions and the group selection controversy. I also describe the main approaches to group selection in the recent literature; fixation, assortative group formation, and reproductive externalities.

Reciprocal behavior, the rewarding of kind acts and the punishment of unkind acts, is relatively well established among adults. We test if reciprocal behavior exists already among children 3-8 years old. Three simple anonymous allocation games are conducted with 242 children. In a first stage,...

A distinctive feature of humans compared to other species is the high rate of cooperation with non-kin. One explanation is that humans are motivated by concerns for social esteem. In this paper we experimentally investigate the impact of anticipated verbal feedback on altruistic behavior. We...

In this paper, we use the classical twin design to provide estimates of genetic and environmental influences on experimentally elicited preferences for risk and giving. Using standard methods from behavior genetics, we find strong prima facie evidence that these preferences are broadly heritable...

Many previous experiments document that behavior in multi-person settings responds to the name of the game and the labeling of strategies. Usually these studies cannot tell whether frames affect preferences or beliefs. In this Dictator game study, we investigate whether social framing effects...