Abstract: This note characterizes every qualified majority voting rule in environments with just two alternatives through anonymity, positive responsiveness, and q-neutrality. Crucially, the latter imposes independence of the labels of the alternatives only for all preference profiles in which some alternative is strictly top-ranked by at least q voters, where q is strictly greater than half of the voter set. Thus, this note generalizes May's (1952, Theorem, p. 682) well-known axiomatic characterization of the simple majority voting rule to qualified majority voting rules. In doing so, it shows that qualified majority voting rules are precisely distinguished by their "degree" of neutrality.
Authors: Héctor HERMIDA-RIVERA.
Keywords: qualified majority, anonymity, positive responsiveness, q-neutrality.
JEL Codes: D71, D82.