The present paper analyzes situations in which groups compete for rents. A major result in the literature has been that there are both cases where larger groups have advantages and cases where they have disadvantages. The paper provides two intuitive criteria which for groups with homogenous...

The present paper analyzes the occurrence of the group-size paradox in situations in which groups compete for rents, allowing for degrees of rivalness of the rent among group members. We provide two intuitive criteria which for groups with homogenous valuations of the rent determine whether...

Traditional economic models of vaccination behavior simply assume that agents free-ride on the vaccination decisions of others. We provide three different models of private provision of a public good, such as a joint production model and a conjectural variation model, to explain how a positive...

Field evidence suggests that agents belonging to the same group tend to behave similarly, i.e., behavior exhibits social interaction effects. Testing for such effects raises severe identification problems. We conduct an experiment that avoids these problems. The main design feature is that each...