Altruists and envious people who meet in contests are symbionts. They do better than a population of narrowly rational individuals. If there are only altruists and envious individuals, a particular mixture of altruists and envious individuals is evolutionarily stable.

This paper considers evolutionarily stable strategies (ESS) in a take-it-or-leave-it offer bargaining game with incomplete information. We find responders reject offers which yield a higher positive material payoff than their outside option. Proposers, in turn, make more attractive offers than...

We consider campaign competition in which candidates compete for votes among a continuum of voters by engaging in persuasive efforts that are targetable. Each individual voter is persuaded by campaign effort and votes for the candidate who targets more persuasive effort to this voter. Each...

We characterize the equilibrium of the all-pay auction with general convex cost of effort and sequential effort choices. We consider a set of n players who are arbitrarily partitioned into a group of players who choose their efforts "early" and a group of players who choose "late". Only the...

In the equilibrium of the all-pay auction with two groups of individual players who move sequentially, only the player with the lowest effort cost has a positive payoff. This payoff and the overall dissipation crucially depend on group composition. -- Sequential all-pay auction ; complete...