Discussion paper

DP13316 Equitable Voting Rules

A celebrated result in social choice is May's Theorem (May, 1952), providing the foundation for majority rule. May's crucial assumption of symmetry, often thought of as a procedural equity requirement, is violated by many choice procedures that grant voters identical roles. We show that a modification of May's symmetry assumption allows for a far richer set of rules that still treat voters equally, but have minimal winning coalitions comprising a vanishing fraction of the population. We conclude that procedural fairness can coexist with the empowerment of a small minority of individuals. Methodologically, we introduce techniques from discrete mathematics and illustrate their usefulness for the analysis of social choice questions.


Yariv, L (2018), ‘DP13316 Equitable Voting Rules‘, CEPR Discussion Paper No. 13316. CEPR Press, Paris & London. https://cepr.org/publications/dp13316