Approval Voting and Fixed Electorate with Dichotomous Preferences

Abstract

We explore the possibility of axiomatic characterization of approval voting when the set of voters is fixed and each voter has a dichotomous preference over the alternatives. We first prove that if the set of alternatives is variable, a social choice rule is approval voting if and only if it satisfies strategy-proofness together with four standard axioms. We then establish a similar characterization in the case of fixed alternatives by introducing a stronger version of strategy-proofness. The latter result answers an open problem left in M. Vorsatz (Approval voting on dichotomous preferences, Social Choice and Welfare, 28:127-141, 2007).

Keywords: Approval voting, Characterization, Dichotomous preferences, Strategy-proofness

JEL Classification: D71; D72