Voting operators map n-tuples of subsets of a given set X of candidates (the voters’ choices) into subsets of X (the social choice). This paper characterizes dictatorial voting operators by means of three conditions (the non-emptiness condition A1, the independence condition A2 and the...

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...