On the Unique Existence of the Nash Equilibrium in Cournot Mixed Oligopoly with Linear Demand and Quadratic Cost Functions

Okuguchi and Yamazaki (2017) prove that if each firm’s marginal cost of its first unit of production is small enough, a public firm and at least one private firm produce the good in the unique Nash equilibrium of Cournot mixed oligopoly. In this paper, we study a concrete model of the mixed oligopoly where firms with a linear or quadratic cost function face a linear market demand function to show how small each firm’s marginal cost of its first unit of production should be.