Theory commonly posits agents who care both for the level of provision of a public good and the extent to which they personally contribute to the cause. Simply put, agents feel some "warm glow" from the donations they make. I discuss a fundraiser devised to exogenously vary the incentive to give...

Because costly punishment is not credible, subgame perfection suggests that punishment will not deter free riding, regardless of the size or structure of groups. However, experiments show that people will punish free riders, even at considerable cost. To examine the implications of agents who...

There is now an extensive literature on "gift exchange" showing that when principals and agents can trade "gifts" (rewards that should not emerge in a competitive equilibrium), exchange becomes more efficient. However, it is not obvious how gift exchange should be organized if the principal's...