Normative Properties of Approval Voting - an Experimental Approach

This paper analyzes the principles by which voters extend their preferences over individual candidates to preferences over sets of candidates in the context of approval voting. Under a system of approval voting, a voter is allowed to vote for as many candidates as he wishes and the candidate(s) with the most approval votes wins. We say that a voter has voted sincerely if he prefers all approved above all non-approved candidates. There are certain assumptions regarding the principles of preference extension under which approval voting will never give a voter an incentive to vote insincerely. However, as presented in this paper, the experimental data show that even the most basic principles put forward in the literature are empirically demonstrated for only limited proportion among the examined groups.