Properties of multiwinner voting rules

Edith Elkind, Piotr Faliszewski, Piotr Skowron, Arkadii Slinko

Abstract: The goal of this paper is to propose and study properties of multiwinner voting rules (with a particular focus on rules based in some way on single-winner scoring rules). We consider, e.g., SNTV, Bloc, k-Borda, STV, and several variants of Chamberlin--Courant's and Monroe's rules, identify two natural approaches to defining multiwinner rules, and show that many of our rules can be captured by one or both of these approaches. We then put forward a number of desirable properties of multiwinner rules, and compare the rules we consider with respect to these properties.