Ostracism, or exclusion by peers, has been practiced since ancient times as a severe form of punishment against transgressors of laws or social norms. The purpose of this paper is to offer a comprehensive analysis on how ostracism affects behavior and the functioning of a social group. We...

We study cooperation in an environment where public good providers face the decision to accept a newcomer to their group. A bottom-up process for accepting new members to social groups reveals individual preferences to include newcomers. Alternatively, inclusion can be decided in a top-down...