UNANIMOUS IMPLEMENTATION: A CASE FOR APPROVAL MECHANISMS

Matias Nunez (1) , Dimitrios Xefteris (2)

1 Université Paris Dauphine-PSL
2 UCY - University of Cyprus [Nicosia]

We consider a class of indirect mechanisms, the Approval ones, in which the players' strategies coincide with the subsets of the outcome space. We focus on the single-peaked domain and we prove that: a) each of these rules is characterized by a unique equilibrium outcome and b) for every strategy-proof single-peaked rule there exists an Approval one that unanimously implements it. That is, Approval rules fix the problem of equilibrium-outcome multiplicity that is inherent to the ensuing games of strategy-proof single-peaked rules and, perhaps more importantly, promote social coherence: the implemented outcome is approved by every player.

Mots clés: Nash Implementation; Strategy-proof; Unanimity; Indirect Mechanisms

Domaines: Économie et finance quantitative [q-fin]

Matias Nunez, Dimitrios Xefteris. UNANIMOUS IMPLEMENTATION: A CASE FOR APPROVAL MECHANISMS . 2016. ⟨hal-01270275v1⟩