A game form constitutionally implements a social choice correspondence if it implements it in Nash equilibrium and, moreover, the associated effectivity functions coincide. This paper presents necessary and sufficient conditions for a unanimous social choice correspondence to be constitutionally...

This paper presents a model which focuses on differences between the competition policy of the EU and antitrust of the U.S. It introduces three versions – Neutral, American, and European. Two-stage game model takes the authority’s perspective and describes options and behavior of antitrust...

We provide an example of an outcome game form with two players for which there is in an open set of utilities for both players such that, in each of the associated games, the set of mixed Nash equilibria induces a continuum of outcome distributions.

Game forms are studied where the acyclicity, in a stronger or weaker sense, of (coalition or individual) improvements is ensured in all derivative games. In every game form generated by an ``ordered voting'' procedure, individual improvements converge to Nash equilibria if the players restrict...

It is not uncommon that a society facing a choice problem has also to choose the choice rule itself. In such situation voters’ preferences on alternatives induce preferences over the voting rules. Such a setting immediately gives rise to a natural question concerning consistency between these...

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 for all cardinal representations of the preference profile. Unlike Maskinʼs...

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...

This paper unifies the theories of Nash implementation and Bayesian implementation in a single framework. Environments considered are such that each agent's characteristics include, in addition to a specification of his private information, a commonly known type parameter, while both attributes...

We demonstrate that no set of neutral and different social choice correspondences exists, so that, if proposed to a group of individuals, it leads to a uniquely defined society, stable in an intuitive sense. Weakening this latter condition makes it possible to reintroduce possibility. This...