This paper examines the role of patent policy in a spatial model of sequential innovation. Initial entrepreneurs develop a new product market and anticipate that subsequent innovation may lead to a product line that consumers value more highly. The likelihood of sequential innovation increases...

We examine the decision to advertise a homogenous good. We show that the likelihood of inefficiently low advertising rests heavily on how one models the mechanism by which advertising affects demand. Regardless of this mechanism, however, there is always a lower bound of concentration below...

We examine the decision to advertise a homogenous good. We show that the likelihood of inefficiently low advertising rests heavily on how one models the mechanism by which advertising affects demand. Regardless of this mechanism, however, there is always a lower bound of concentration below...

Cost synergies are an explicitly recognized justification for a two-firm merger, and empirical techniques are now widely used to assess the impact of cost-reducing mergers on prices and welfare in the post-merger market. We show that if the merger occurs in a vertically product differentiated...

This paper offers an analysis of the evolution of e-commerce markets. We develop a model in which an initial group of small, no-name click firms create such markets by offering horizontally differentiated customized or versioned products and competing in prices. Subsequently, a traditional brick...

We examine the decision to advertise a homogenous good. We show that the likelihood of inefficiently low advertising rests heavily on how one models the mechanism by which advertising affects demand. Regardless of this mechanism, however, there is always a lower bound of concentration below...

We develop a model of innovation in which entrepreneurs develop a new (differentiated) product market that is subsequently exploited by a well-established firm that "stretches" its brand to enter a new market as "fast second". In this setting, there is a positive externality to the pioneering...