Uniqueness of Cournot Equilibrium: New Results from Old Methods.

This paper provides sufficient conditions for the existence of a unique Cournot equilibrium. Previous uniqueness results have depended on an assumption of nondegeneracy of equilibrium. As the authors illustrate, this assumption often fails in multistage games with proper Cournot subgames. Since their uniqueness results do not depend on this assumption, they are more widely applicable. Copyright 1991 by The Review of Economic Studies Limited.