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...

We describe a dynamic model of costly information sharing, where private information affecting collective-value actions is transmitted by social proximity. Individuals make voluntary contributions towards the provision of a pure public good, and information transmission about quality of...

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...

Consider a setting in which several groups of individuals with common interests (clubs) compete with each other for recognition by other individuals. Depending on the context, recognition may be expressed by these other individuals joining a club, or choosing one club to admire. Clubs compete by...

We compare single ballot vs dual ballot elections under plurality rule, assuming sincere voting and allowing for partly endogenous party formation. Under the dual ballot, the number of parties is larger but the influence of extremist voters on equilibrium policy is smaller, because their...

Take-it or leave-it offers are probably as old as mankind. Our objective here is, first, to provide a, probably subjectively-colored, recollection of the initial ultimatum game experiment, its motivation and the immediate responses. Second, we discuss important extensions of the standard...