We characterize the structure of the set of core matchings of an assignment game (a two-sided market with transfers). Such a set satisfies a property we call consistency. Consistency of a set of matchings states that, for any matching v, if, for each agent i there exists a matching ? in the set...

We present a nonparametric "revealed-preference test" for gross substitutes in demand for two goods. (JEL D01, D11)