Cournot-Walras equilibria in markets with a continuum of traders

Summary In a model with a nonatomic continuum of traders some of which behave strategically while the others remain price-takers, the set of Cournot-Walras equilibria coincides with the set of Walras equilibria. This property is no longer valid when the strategic agents are represented by atoms.It is a pleasure to acknowledge the stimulating discussions we had with R. Amir about the question examined in the present work.