We investigate the emergence and enforcement of contribution norms to public goods in homogeneous and heterogeneous groups. With survey data we demonstrate that uninvolved individuals hold well defined yet conflicting normative views of fair contribution rules related to efficiency, equality,...

We study the endogenous formation of networks in a controlled experiment. Subjects derive benefits from being linked to others and incur costs for links they make. The theoretically predicted network has a "star"-type architecture, with "periphery" subjects linking to a unique "center". This...