We report the results of a field experiment with bicycle messengers in Switzerland and the United States. Messenger work is individualized enough that firms can choose to condition pay on it, but significant externalities in messenger behavior nonetheless give their on-the-job interactions the...

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...

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...

Monitoring by peers is often an effective means of attenuating incentive problems. Most explanations of the efficacy of mutual monitoring rely either on small group size or on a version of the Folk theorem with repeated interactions which requires reasonably accurate public information...