Abstract: can a rational society be liberal and fair? This paper answers this question by investigating under which conditions there exists a liberal, fair and Nash implementable social choice rule. A social choice rule is liberal if and only if for every player, there exists an issue such that when this player unconditionally prefers one of its features, the optimal outcome set is a subset of those outcomes with that feature. A social choice rule is fair if and only if when it is no worse to be anyone in one outcome than to be someone else in some other outcome, then the latter is not socially optimal. A social choice rule is Nash implementable if and only if there exists a mechanism whose set of Nash equilibrium outcomes coincides with the set of socially optimal ones for every preference profile.

Authors: Fatma Aslan & Hector Hermida-Rivera.

Keywords: fairness, mechanism, Nash, equilibrium, implementability.

JEL Codes: D71, D82.