“Three Essays on Product Differentiation”

The models developed in the three chapters of this dissertation all belong to the field of theoretical Industrial Organization. In the first chapter a model of spatial competition is developed, it describes the space as a source of market power, indeed, in such product space firms make use of product differentiation. In the second chapter, a model of endogenous growth studies the impact of patent imperfections on the R&D activities devoted to introduce new varieties through product differentiation. Following a new line of research, I analyze the relationship between the degree of strategic interaction among firms and the endogenous growth rate. The last chapter makes use of the product differentiation framework in order to explain the profitability for multiproduct companies to choose their internal organizational structure. The model analyzes the price-setting behavior of multiproduct firms which offer either a set of close substitutes (market segmentation) or a set of distant substitutes (market interlacing). In order to maximize profits, each company may allow its product managers to behave either independently or cooperatively.