Social choice and welfare vol:22 issue:3 pages:437-445
Consider the problem of aggregating preferences. A coalition is manipulative if it is able to force the outcome of the aggregation process. In the framework of topological aggregation (due to Chichilnisky) the family of manipulative coalitions constitutes an ultrafilter. This result holds for finite and for infinite populations, and supports the analogy between the Chichilnisky and the Arrovian aggregation model.