We compare a partners condition where the same small group of subjects plays a repeated public good game to a strangers condition where subjects play this game in changing group formations. Subjects in the partners condition contribute from the first period on significantly more to the public...

This paper experimentally explores how the enforcement of cooperative behavior in a social dilemma is facilitated through institutional as well as emotional mechanisms. Recent studies emphasize the importance of negatively valued emotions, such as anger, which motivate individuals to punish free...