This paper proves the existence of a symmetric equilibrium with multiproduct firms using a nested logit model of demand. The demand model is parameterized by two variables that characterize different dimensions of preference for variety. These reflect intragroup heterogeneity and intergroup...

The authors provide a comparison of three spatial price policies: uniform pricing, mill pricing, and spatial price discrimination. Profits, consumer surplus, and social surplus are compared in a duopoly model. Until recently, oligopoly analysis has been stalled because of nonexistence of...

We analyse an oligopoly model incorporating horizontal differentiation and quality differences. High quality goods are overpriced and underproduced. When the market is fairly well covered, low quality products may be profitable when their net social contribution is negative, implying excessive...