Monetary theorists have advanced an intriguing notion: we exchange money to make up for a lack of enforcement, when it is difficult to monitor and sanction opportunistic behaviors. We demonstrate that, in fact, monetary equilibrium cannot generally be sustained when monitoring and punishment...

While there is an extensive literature on the theory of infinitely repeated games, empirical evidence on how %22the shadow of the future%22 affects behavior is scarce and inconclusive. We simulate infinitely repeated prisoner's dilemma games in the lab by having a random continuation rule. The...

I experimentally investigate a new game that modifies the prisoner's dilemma. In this game, as opposed to the regular prisoner's dilemma, there is no tradeoff between cooperation and strategic risk (uncertainty regarding the other player's strategy) that is the leading explanation for low...

Case studies of cartels and recent theory suggest that repeated communication is key for stable cooperation in environments where signals about others' actions are noisy. However, empirically the exact role of communication is not well understood. We study cooperation under different monitoring...

We consider mixed populations (N=21) of genuine (humans) and artificial (robots) agents, repeatedly interacting in small groups whose composition is changed randomly from round to round. Our purpose is to study the spread of cooperative or non-cooperative behavior in the population over time by...