Cournot Retrouvé Under Price or Supply Function Competition

This paper aims at participating in the long-lasting debate about the analytical foundations of the Cournot equilibrium. In a homogeneous oligopoly, under standard regularity conditions, we prove that Cournot-Nash emerges both under (i) price competition and Cournot conjectures; and (ii) supply function competition with ex post market clearing. We demonstrate both results within a model of exogenous product differentiation.