Development of human societies requires cooperation among unrelated individuals and obedience to social norms. Although … punishment is widely agreed to be potentially useful in fostering cooperation, many recent results in psychology and economics … highlight punishments' failures in this regard. These studies ignore punishments' social effects, and particularly its role in …

and its impact on cooperation of its members are yet not well understood. We experimentally investigate community choice …

can increase the cooperation level of individuals in the group. …

the role of details of the environment that may alter focal contribution norms in an important way. …

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 …

We show that peer sanctioning increases cooperation in public goods experiments more in unequally endowed groups than …

support near e¡Ë cient levels of contributions to a public good. Cooperation may also be supported if altruistic individuals … cooperation may be less than additive. Using a utility function embodying both reciprocity and altruism we show that unconditional … contribution costs and punishment costs. The range over which altruism inhibits cooperation and reduces material payo¢´s is greater …