3) Consider an oligopoly model with N symmetric firms whose marginal cost is c. Assume that they operate in a market with a constant elasticity of demand function P(Q) = Q : (& > 1) . Show that, under Cournot competition, the profit of each firm is an increasing function of marginal cost. 4) Discuss a two-stage model of oligopolistic competition and analyze how the strategic effect may "distort" the choice of the commitment variable