An equivalence principle for perfectly competitive economies

Four axioms are placed on a correspondence from smooth, non-atomic economies to their allocations. We show that the axiomscategorically determinethe (coincident) competitive-core-value correspondence. Thus any solution is equivalent to the above three if, and only if, it satisfies the axioms. In this sense our result is tantamount to an "equivalence principle." At the same time, our result implies that the three solutions themselves are determined by the axioms and so serves as an axiomatic characterization of the well-known competitive (or core, or value) correspondence.Journal of Economic LiteratureClassification Numbers: C71, D41, D51, D63.