Consider a voting procedure where countries, states, or districts comprising a union each elect representatives who then participate in later votes at the union level on their behalf. The countries, provinces, and states may vary in their populations and composition. If we wish to maximize the...

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...

We study the possibility of designing satisfactory ex post incentive compatible single valued direct mechanisms in interdependent values environments, characterized by the set of agents’ type profiles and by their induced preference profiles. For environments that we call knit and strict, only...

Pierre Daunou, a contemporary of Borda and Condorcet during the era of the French Revolution and active debates on alternative voting rules, proposed a rule that chooses the strong Condorcet winner if there is one, otherwise eliminates Condorcet losers and uses plurality voting on the remaining...

We stress the importance that Arrow attached to studying the role of domain conditions in determining the validity of his impossibility theorem, a subject to which he devoted two chapters of Social Choice and Individual Values. Then we partially survey recent results about the role of domain...

We study collective decision-making procedures involving the formation of an agenda of issues and the subsequent vote on the position for each issue on the agenda. Issues that are not on the agenda remain unsettled. We use a protocol-free equilibrium concept introduced by Dutta et al. (2004) and...

We propose three mechanisms to reach a compromise between two opposite parties that must choose one out of a set of candidates and operate under full information. All three mechanisms weakly implement the Unanimity Compromise Set. They all rely on the use of some Rule of k Names, whereby one of...