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：在具有序数偏好的社会选择理论中，若向一个偏好配置中添加一位将某备选方案唯一排在第一位的投票者，不会导致该方案从获胜转为落败，则称该投票方法满足积极介入公理。本文证明了一个关于该公理的新不可能性定理：不存在任何满足积极介入的序数投票方法能同时满足孔多塞胜者与败者准则、可解性，以及孔多塞方法常见的协变性——即获胜者的选择仅取决于多数票差按大小的排序。