Howard (1992) argues that the Nash bargaining solution is not Nash implementable, as it does not satisfy Maskin monotonicity. His arguments can be extended to other bargaining solutions as well. However, by defining a social choice correspondence that is based on the solution rather than on its...

A common real-life problem is to fairly allocate a number of indivisible objects and a fixed amount of money among a group of agents. Fairness requires that each agent weakly prefers his consumption bundle to any other agent's bundle. In this context, fairness is incompatible with budget-balance...

In U.S. presidential elections, voters in noncompetitive states seem not to count — and so have zero voting power, according to the Banzhaf and other voting-power indices — because they cannot influence the outcome in their states. But because the electoral votes of these states are...

Social Choice traditionally employs the preferences of voters or agents as primitives. However, in most situations of constitutional decision-making the beliefs of the members of the electorate determine their secondary preferences or choices. Key choices in US political history, such as the...

Strategy‐proofness (SP) is a sought‐after property in social choice functions because it ensures that agents have no incentive to misrepresent their private information at both the interim and ex post stages. Group strategy‐proofness (GSP), however, is a notion that is applied to the ex...

Collective choice problems on sets in ${\frak R}_+^n$ arise naturally in economics. Such problems have been extensively studied both in the theory of revealed preferences (Peters and Wakker, 1991) and in axiomatic bargaining theory under the assumption of convexity. However, our knowledge of...

In a matching problem between students and schools, a mechanism is said to be robustly stable if it is stable, strategy-proof, and immune to a combined manipulation, where a student first misreports her preferences and then blocks the matching that is produced by the mechanism. We find that even...

A set of jobs need to be served by a server which can serve only one job at a time. Jobs have processing times and incur waiting costs (linear in their waiting time). The jobs share their costs through compensation using monetary transfers. In the first part, we provide an axiomatic...

We consider a committee that consists of n members with one person one vote approving a proposal if the number of affirmative votes from the members reaches threshold k. Which threshold k between 1 and n is "good" for the committee? We suppose that if a new threshold k' proposed by some...

In this paper we address several issues related to collective dichotomous decision-making by means of quaternary voting rules, i.e., when voters may choose between four actions: voting yes, voting no, abstaining and not turning up-which are aggregated by a voting rule into a dichotomous...