This paper studies how competition between groups affects cooperation. In the control condition, pairs of subjects play an indefinitely repeated Prisoner's Dilemma game without external competition. In the treatment, two pairs compete against each other. No monetary rewards are tied to winning,...

Based on an experimental analysis of a simple monetary economy we argue that a monetary system is more stable than one would expect from individual rationality. Weshow that positive reciprocity stabilizes the monetary system, provided everyparticipant considers accepting money as a reasonable...

This paper contributes to the micro-foundation of money in centralizedmarkets with idiosyncratic uncertainty. It shows existence of stationarymonetary equilibria and ensures that there is an optimum quantity ofmoney. The rational solution of our model is compared with actual be-havior in a...

This paper deploys a novel experiment to compare four theories that explain both selfish and non-selfish cooperation. The four theories capture incomplete information (à la Kreps et al. (1982)) alongside the following four non-selfish motives: caring about others (Altruism), being conscientious...

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

Human players in our laboratory experiment received flow payoffs over 120 seconds each period from a standard Hawk-Dove bimatrix game played in continuous time. Play converged closely to the symmetric mixed Nash equilibrium under a one-population matching protocol. When the same players were...

Mixed Nash equilibria are a cornerstone of game theory, but their empirical relevance has always been controversial. We study in the laboratory two games whose unique NE is in completely mixed strategies; other treatments include the matching protocol (pairwise random vs population...

We study prisoner's dilemmas played in continuous time with flow payoffs over 60 seconds. In most cases, the median rate of mutual cooperation rises to 90% or more. Control sessions with 8-time repeated matchings achieve less than half as much cooperation, and cooperation rates approach zero in...

Human players in our laboratory experiment converge closely to the symmetric mixed Nash equilibrium when matched in a single population version of the standard Hawk-Dove game. When matched across two populations, the same players show clear movement towards an asymmetric (and very inequitable)...

We report experiments designed to test between Nash equilibria that are stable and unstable under learning. The 'TASP' (Time Average of the Shapley Polygon) gives a precise prediction about what happens when there is divergence from equilibrium under fictitious play like learning processes. We...