21 January 2026, Computational Social Choice Seminar, Xiaochen Yu

Please note: this event has been rescheduled to Wednesday 21 January 2026.

Abstract

Under the Minimax voting method, a candidate wins if her maximum margin of loss in pairwise majority comparisons is the smallest. It is one of the few Condorcet consistent voting methods guaranteeing that truthful voting does not make a voter's unique favorite candidate lose. We show that two more axioms, one requiring that there can be only one winner if no two pairwise majority margins are equal and the other called Ordinal Margin Invariance stating that only the relative ordering of margins matters, suffice to precisely pin down Minimax on profiles without equal margins. We also axiomatize Minimax over all profiles. This is done by adding an axiom of continuity and either adding a further axiom of monotonicity or replacing the unique winner axiom above with Weak Positive Responsiveness, a weakening of Positive Responsiveness that features in May's theorem for two-candidate voting.

For more information on the Computational Social Choice Seminar, please consult https://staff.science.uva.nl/u.endriss/seminar/.