How should we make value judgments about wealth inequality? Harsanyi (1953) proposes to take an individual who evaluates her well-being by expected utility and ask her to evaluate the wealth possibilities ex-ante (i.e. before she finds her place in society, i.e., under the "veil of ignorance" of...

We consider the spread of a harmful state through a population divided into two groups. Interaction patterns capture the full spectrum of assortativity possibilities. We show that a central planner who aims for eradication optimally either divides equally the resources across groups, or...

We study symmetric play in a class of repeated games when players are patient. We show that, while the use of symmetric strategy profiles essentially does not restrict the set of feasible payoffs, the set of equilibrium payoffs is an interesting proper subset of the feasible and individually...