Egalitarianism and meritocracy are competing principles to distribute the joint benefits of cooperation. We examine the consequences of letting members of society vote between those two principles, in a context where individuals must joint with others into coalitions of a certain size to become...

A decision maker (DM) may not perfectly maximize her preference over the feasible set. She may feel it is good enough to maximize her preference over a sufficiently large consideration set; or just require that her choice is sufficiently well-ranked (e.g., in the top quintile of options); or...

This chapter surveys the literature on strategy proofness from a historical perspective. While I discuss the connections with other works on incentives in mechanism design, the main emphasis is on social choice models.

Two candidates competing for election may raise some issues for debate during the electoral campaign, while avoiding others. We present a model in which the decision to introduce an issue, or to reply to the opponent's position on one that she raised, may result in further additions to the list...

The main purpose of the Handbook of Utility Theory is to make more widely available some recent developments in the area. The editors selected a list of topics that seemed ripe enough to be covered by review articles. Then they invited contributions from researchers whose expert work had come to...

In this note we show that no solution to coalition formation games can satisfy a set of axioms that we propose as reasonable. Our result points out that solutions to the coalition formation cannot be interpreted as predictions of what would be resting points for a game in the way stable...

The conditions of strong Condorcet winner consistency and strong Condorcet loser consistency are, in essence, universally accepted. However, there are many situations in which they are silent. The weak counterparts of these properties suffer from the fatal flaw that a weak Condorcet winner can...

This paper studies collective choice rules whose outcomes consist of a collection of simultaneous decisions, each one of which is the only concern of some group of individual in society. The need for such rules arises in different contexts, including the establishment of jurisdictions, the...

We observe that many salient rules to allocate private goods are not only (partially) strategy-proof, but also (partially) group strategy-proof, in appropriate domains of definition. That is so for solutions to matching, division, cost sharing, house allocation and auctions, in spite of the...

Consider the following principle regarding the performance of collective choice rules. "If a rule selects alternative x in situation 1, and alternative y in situation 2, there must be an alternative z, and some member of society whose appreciation of z relative to x has increased when going from...