Bipolar Multicandidate Elections with Corruption

Abstract

The goals of democratic competition are not only to implement a majority's preference on policy questions, but also to provide a deterrent against corrupt abuse of power by political leaders. We consider a simple model of multicandidate elections in which different electoral systems can be compared according to these two criteria. Among a wide class of single-winner scoring rules, only approval voting is found to satisfy both effectiveness against corruption and majoritarianism for this model.