In social choice theory with ordinal preferences, a voting method satisfies the axiom of positive involvement if adding to a preference profile a voter who ranks an alternative uniquely first cannot cause that alternative to go from winning to losing. In this note, we prove a new impossibility theorem concerning this axiom: there is no ordinal voting method satisfying positive involvement that also satisfies the Condorcet winner and loser criteria, resolvability, and a common invariance property for Condorcet methods, namely that the choice of winners depends only on the ordering of majority margins by size.

翻译：在基于序数偏好的社会选择理论中，若在偏好分布中添加一位将某一备选方案排在第一位的选民，不会导致该备选方案从获胜变为失败，则称投票方法满足积极介入公理。本文证明了关于该公理的一个新不可能性定理：不存在同时满足孔多塞胜者与败者准则、可分辨性以及孔多塞方法常见不变性性质（即胜者选择仅取决于多数差额按规模排序）的序数投票方法。