Infrastructure networks are a key feature of an economy. Their functionality depends on the connectivity and sizes of different components and they face a variety of threats, from natural disasters to intelligent attacks. How should networks be defended and designed to ensure the best functionality?

We analyze the problem of optimal monopoly pricing in social networks where agents care about consumption or prices of their neighbors. We characterize the relation between optimal prices and consumersʼ centrality in the social network. This relation depends on the market structure (monopoly...

The division problem under constraints consists of allocating a given amount of an homogeneous and perfectly divisible good among a subset of agents with single-peaked preferences on an exogenously given interval of feasible allotments. We characterize axiomatically the family of extended...

We consider a mechanism design problem in economies with increasing returns. We construct a new class of rules, called w-hybrid rules, and characterize them by strategy-proofness, anonymity, envy-freeness, consumer sovereignty, and non-bossiness. We show that w-hybrid rules improve the supremal...

We consider full implementation in complete-information environments when agents have an arbitrarily small preference for honesty. We offer a condition called separable punishment and show that when it holds and there are at least two agents, any social choice function can be implemented by a...

An aggregation rule maps each profile of individual strict preference orderings over a set of alternatives into a social ordering over that set. We call such a rule strategy-proof if misreporting one's preference never produces a different social ordering that is between the original ordering...

This paper inspires from a real-life assignment problem faced by the Mexican Ministry of Public Education. We introduce a dynamic school choice problem that consists in assigning positions to overlapping generations of teachers. From one period to another, teachers can either retain their...

A domain of preference orderings is a random dictatorship domain if every strategy-proof random social choice function satisfying unanimity defined on the domain is a random dictatorship. Gibbard (1977) showed that the universal domain is a random dictatorship domain. We ask whether an arbitrary...

We analyze the problem of aggregating judgments over multiple issues from the perspective of whether aggregate judgments manage to efficiently use all voters' private information. While new in judgment aggregation theory, this perspective is familiar in a different body of literature about...

A social choice function may or may not satisfy a desirable property depending on its domain of definition. For the same reason, different conditions may be equivalent for functions defined on some domains, while not in other cases. Understanding the role of domains is therefore a crucial issue...