Uniqueness of general economic equilibrium

For a well-known economic model involving n commodities that are offered for sale, it is proved that there is at most one normalized equilibrium if the values of a certain matrix-valued function of order (n - 1) are Hicksian (i.e., have positive principal minors) throughout its domain of definition. The condition has a nice interpretation, and the result differs from an earlier (and very differently proved) uniqueness result of Arrow and Hahn primarily in that the class of excess-demand functions considered here is considerably less restricted in an important sense.