In a seminal paper, Grossman and Helpman (1994) introduced a framework to understand how lobbying influences the choice of import/export tariffs. In this paper we extend their analysis and assume that lobbies have private information to analyze the effects of information transmission in a...

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...

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...

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...

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...

A collective decision problem is described by a set of agents, a profile of single-peaked preferences over the real line and a number of public facilities to be located. We consider public facilities that do not suffer from congestion and are non-excludable. We characterize the class of rules...

We study resource allocation with multi-unit demand, such as the allocation of courses to students. In contrast to the case of single-unit demand, no stable mechanism, not even the (student-proposing) deferred acceptance algorithm, achieves desirable properties: it is not strategy-proof and the...

A benevolent Planner wishes to assign an indivisible private good to n claimants, each valuing the object differently. Individuals have quasi-linear preferences. Therefore, the possibility of transfers is allowed. A second-best efficient mechanism is a strategy-proof and anonymous mechanism that...

A contract auction establishes a contract between a center and one of the bidders. As contracts may describe many terms, preferences over contracts typically display indifferences. The Qualitative Vickrey Auction (QVA) selects the best contract for the winner that is at least as good for the...

A monopolist sells a good whose value depends on the number of buyers who adopt it as well as on their private types. The seller coordinates the buyersʼ adoption decisions based on their reported types, and charges them the price based on the number of adoptions. We study ex post implementable...