The axioms that characterize the generalized Gini social evaluation orderings for one-dimensional distributions are extended to the multidimensional attributes case. A social evaluation ordering is shown to have a two-stage aggregation representation if these axioms and a separability assumption...

This note provides an introduction to the accompanying previously unpublished paper by Allan Gibbard in which he establishes his oligarchy theorem. Copyright Springer-Verlag Berlin Heidelberg 2014

The collective rationality requirement in Arrow's theorem is weakened to demanding a social quasi-ordering (a reflexive and transitive but not necessarily complete binary relation). This weakening leads to the existence of a group such that (a) whenever all members of the group strictly prefer...