Oligopolistic vs. monopolistic competition : Do intersectoral effects matter?
Abstract
Recent extensions of the standard Dixit-Stiglitz (1977) model, that go beyond the CES sub-utility assumption, while maintaining monopolistic competition, have mainly emphasized the role of intrasectoral substitutability. We argue that introducing oligopolistic competition can be an
alternative extension, still tractable, allowing to restore the role of intersectoral substitutability and reinforcing the general equilibrium dimension of the model. For this purpose, we use the concept of oligopolistic equilibrium and derive a comprehensive formula to characterize the set of
potential equilibria with varying competitive toughness. For two particular competitive regimes, price competition and quantity competition, we show how, with strategic interactions, procompetitive or anti-competitive effects now depend on the elasticity of intersectoral substitution as compared to the elasticity of intrasectoral substitution.