The Distortion of Binomial Voting Defies Expectation

Yannai Gonczarowski, Gregory Kehne, Ariel D. Procaccia, Ben Schiffer, Shirley Zhang

Keywords: computational social choice, statistics, distortion

TL;DR: A new voting rule called binomial voting provides strong guarantees with respect to expected distortion, a novel measure of social desirability.

Abstract: In computational social choice, the distortion of a voting rule quantifies the degree to which the rule overcomes limited preference information to select a socially desirable outcome. This concept has been investigated extensively, but only through a worst-case lens. Instead, we study the expected distortion of voting rules with respect to an underlying distribution over voter utilities. Our main contribution is the design and analysis of a novel and intuitive rule, binomial voting, which provides strong distribution-independent guarantees for both expected distortion and expected welfare.

Submission Number: 3808