A mechanism implements a social choice correspondence f in mixed Nash equilibrium if at any preference profile, the set of all pure and mixed Nash equilibrium outcomes coincides with the set of f-optimal alternatives at that preference profile. This definition generalizes Maskin’s definition...

For each set of candidates at state and each profile of voters' preferences over running candidates a voting corresponsence selects a set of candidates. following Dutta, Jackson and Le Breton (Econometrica 2001) a voting correspondence is candidate stable if a candidate never benefits from...

This chapter gives a flavour of recent theoretical work on coalition formation and political parties. I survey recent work on both pre-election coalition formation and post election coalition (or government) formation. A number of alternative rationales for the formation of parties are compared...

We extend the analysis of Dutta, Jackson and Le Breton (Econometrica 2001) on strategic candidacy to probabilistic environments. For each configuration of the agenda and each profile of voters' preferences over running candidates a probabilistic voting procudure selects a lottery on the set of...

This paper studies the dominance-solvability (by iterated deletion of weakly dominated strategies) of general scoring rule voting games. The scoring rules we study include Plurality rule, Approval voting, Negative Plurality Rule, Borda rule and Relative Utilitarianism. We provide a...

Voting Power Indices enable the analysis of the distribution of power in a legislature or voting body which uses weighted voting. Although the approach, based on co-operative game theory, has been known for a long time it has not been very widely applied, in part because of the difficulty of...

We develop a definition of equilibrium for agenda formation in general voting settings. The definition is independent of any protocol. We show that the set of equilibrium outcomes for any Pareto efficient voting rule is uniquely determined. We also show that for such voting rules, if preferences...

We introduce the framework of parameterized collections of games with and without sidepayments and provide three nonemptiness of approximate core theorems. The parameters bound (a) the number of approximate types of players and the size of the approximation and (b) the size of nearly effective...

In general in an organization whose system of governance involves weighted voting, a member's weight in terms of the number of votes and the formal power it represents differ. Power indices provide a means of analyzing this difference. The paper uses new algorithms for computing power indices...

We present a dynamic model of jurisdiction formation in a society of identical people. The process is described by a Markov chain that is defined by myopic optimization on the part of the players. We show that the process will converge to a Nash equilibrium club structure. Next, we allow for...