Survey evidence on conditional norm enforcement

We analyze survey evidence on individuals' willingness to sanction law violations – such as evading taxes, drunk driving and fare dodging – by disapproval or social exclusion. Our data show that people condition their willingness to sanction a norm violation on their belief about its frequency. The more commonly a norm violation is believed to occur, the lower individuals' inclination to punish it. Our findings are in line with models of social norms and offer an alternative interpretation of the ‘broken windows’ effect.