A Majority Rule Philosophy for Instant Runoff Voting

Abstract

We present the concept of ordered majority rule, a property of Instant Runoff Voting, and compare it to the familiar concept of pairwise majority rule of Condorcet methods. Ordered majority rule establishes a social order among the candidates such that that relative order between any two candidates is determined by voters who do not prefer another major candidate. It ensures the election of a candidate from the majority party or coalition while preventing an antagonistic opposition party or coalition from influencing which candidate that may be. We show how IRV is the only voting method to satisfy ordered majority rule, for a self-consistently determined distinction between major and minor candidates, and that ordered majority rule is incompatible with the properties of Condorcet compliance, independence of irrelevant alternatives, and monotonicity. Finally, we present some arguments as to why ordered majority rule may be preferable to pairwise majority rule, using the 2022 Alaska special congressional election as a case study.Comment: 11 page