Generalized Symmetry Conditions at a Core Point

Previous analyses have shown that if a point is to be a core of a majority-rul e voting game in Euclidean space when preferences are smooth, then the utility gradients at the point must satisfy certain restrictive symmetry conditions. In this paper, these results are generalized t o the case of an arbitrary voting rule, and necessary and sufficient conditions, expressed in terms of the utility gradients of "pivotal' ' coalitions, are obtained. Copyright 1987 by The Econometric Society.