Elections and Strategic Voting: Condorcet and Borda

Résumé

We show that majority rule is uniquely characterized among voting rules by strategy-proofness, the Pareto principle, anonymity, neutrality, independence of irrelevant alternatives, and decisiveness. Furthermore, there is an extension of majority rule that satisfies these axioms on any preference domain without Condorcet cycles when voters are sufficiently risk-averse. If independence is dropped, then, for the case of three candidates, the remaining axioms characterize exactly two voting rules – majority rule and rank-order voting – on rich domains (domains for which no candidate is always extremal, i.e., best or worst).