A Note on Qualified Majority Voting Rules

Abstract

This note characterizes every qualified majority voting rule in environments with just two alternatives through anonymity, responsiveness, and q-neutrality. Crucially, the latter imposes independence of the labels of the alternatives if and only if some alternative is strictly top-ranked by at least q voters. Thus, this note generalizes May's (1952, Theorem, p. 682) characterization of the simple majority voting rule to qualified majority voting rules. In doing so, it shows that qualified majority voting rules are distinguished by their degree of neutrality.