We study the stability of voluntary cooperation in response to varying group growth rates. Using a laboratory public … cooperation. We then study the effect of exogenously varying growth rates on cooperation. Slow growth yields higher cooperation …-reinforcing beliefs persisting under slower growth. Allowing incumbent group members to select growth rates also sustains high cooperation …

when group members have opportunities to punish low contributors. Cooperation may also be supported if individuals are … punishment costs. The negative effect of altruism on cooperation and material payoffs is greater the stronger is the reciprocity …

can promote cooperation through a combination of sorting and opportunistic signaling, with late period defections by … remains unclear. In each of six treatments that vary the cooperation premium and the informational basis for reputation …, that with a high cooperation premium and good information, investment in reputation grows across sets of finitely …

We present results from a novel experiment on the effect of a policy designed to encourage cooperation in a prisoner …'s dilemma game. We find that the effect of this policy on the level of cooperation is greater when it was chosen democratically …

higher the levels of cooperation. We compare the behavior from these in finitely repeated games with behavior from finitely … repeated games of the same expected length and we find that there is more cooperation in the in finitely repeated games …

two relevant features of social life into the experiment: (i) subjects can migrate across groups with different … key to the quick emergence of an efficient culture of universal cooperation because the more prosocial subjects populate … social norm of high cooperation. This norm appears to guide subjects' cooperation and punishment choices, including the …