We provide a direct test of the role of social preferences in voluntary cooperation. We elicit individuals' cooperation preference in one experiment and make a point prediction about the contribution to a repeated public good. This allows for a novel test as to whether there are types of players...

Field evidence suggests that people belonging to the same group often behave similarly, i.e.,behaviour exhibits social interaction effects. We conduct an experiment that avoids theidentification problem present in the field. Our novel design feature is that each subjectsimultaneously is a member...