A stronger criterion for the Weak Weak Axiom

The Weak Weak Axiom (WWA) is a milder version of the Weak Axiom of Revealed Preference (WA) and is equivalent to pseudomonotonicity of the excess demand function. Since the WWA guarantees uniqueness of the equilibrium in a broad class of general equilibrium models, it is important to have criteria to check when the WWA holds. In this paper, a new and more general characterization of pseudomonotonicity for C-1 maps is provided. Using this result, we obtain a stronger criterion for the WWA than those available in the literature. A complete characterization of the WA for excess demand functions is also offered and other important existing results are obtained in a straightforward fashion. (C) 2003 Elsevier B.V. All rights reserved.