Majority-approval social choice

Abstract

This note axiomatically proposes a social choice rule called majority approval, which coincides with the simple majority rule when the latter is decisive (i.e., contains no top cycles), and otherwise coincides with approval voting (Brams and Fishburn, 1978) defined on the top cycle set. We compare our rule to other social choice rules that prioritize preference information over approval information, and show that it stands out for its appealing properties. In addition, we provide axiomatization for a version of majority approval that satisfies the Pareto criterion.