Impossibility theorems for preference correspondences based on a new monotonicity concept are discussed. Here monotonicity means that if preferences update in such a way that they get closer to an outcome then at the new situation this outcome remains chosen. Strong monotonicity requires further...

This note provides an alternative derivation of the leximin principle using the framework of Harsanyi’s (1953) equi-probability model. We demonstrate that the leximin principle is concluded if and only if the preference ordering of the impartial observer obeys strong monotonicity and complete...

We give an objective meaning to the concept of taxable capacity and establish a theoretical link between Optimal Taxation Theory (OTT) and the proposals of the Carter and Meade Reports, solving at the same time Kay’s (2008) criticism to both approaches.

We provide conditions under which a Condorcet winner exists when voters are exogenously distributed in groups, with preferences satisfying the single-crossing property separately inside each group. We also show that the majority voting social preference is acyclic.

In this paper, virtual implementation is restricted to deliver, on the equilibrium path, either a socially optimal outcome or a status quo: an outcome fixed for all preference profiles. Under such a restriction, for any unanimous and implementable social choice function there is a dictator, who...

We study dispute resolution in the compromise model of Börgers and Postl (2009), which provides an alternative framework for analyzing the real-world procedure of tri-offer arbitration studied in Ashenfelter et al. (1992). Two parties involved in a dispute have to choose between their...

In a model with finitely many agents who have single-dipped Euclidean preferences on a disc in the Euclidean plane, a rule assigns to each profile of reported dips a point of the disc. It is proved that any strategy-proof and Pareto optimal rule is dictatorial. This framework models situations...

We study the assignment of agents to clubs in a frictional market environment. Club entry is endogenous and clubs compete by posting reserve prices in a competing auctions game prior to the agents’ decisions regarding which club to visit. The competing auctions equilibrium is constrained...

The universally beneficial manipulation conjecture of Campbell and Kelly states that for a social choice rule, if everyone gains as a result of any optimal manipulation, then the rule satisfies universally beneficial manipulation, i.e., everyone gains as a result of any manipulation, optimal or...

We provide a short proof for the following characterization of the core in housing markets first proved by Ma (1994): the core is the only rule that satisfies strategy-proofness, Pareto efficiency and individual rationality.