Price-quantity competition with varying toughness

In order to formalize the variety of oligopolistic competition regimes, we adopt an approach (pioneered by Shubik, 1959) where firms behave strategically both in price and quantity. The corresponding concept of oligopolistic equilibriumallo ws for a parameterized continuum of regimes with varying competitive toughness. In particular, the Cournot and the competitive outcomes coincide, respectively, with the softest and the toughest oligopolistic equilibrium outcome. The set of all equilibrium outcomes are compared with those obtained in three alternative approaches, respectively based on pricing-schemes, conjectural variations and supply functions. Finally, we explore the possibility of endogenizing strategically the choice of competitive toughness by the firms