We discuss survey evidence on individuals' willingness to sanction norm violations such as evading taxes, drunk driving, fare dodging, or skiving off work by expressing disapproval or social exclusion. Our data suggest that people condition their sanctioning behavior on their belief about the...

Economic and social interaction takes place between individuals with heterogeneous characteristics. We investigate experimentally the emergence and informal enforcement of different contribution norms to a public good in homogeneous and different heterogeneous groups. When punishment is not...