Quality regulation attempts to ensure quality and foster competition by reducing vertical differentiation, but it may also have adverse effects on market structure. We study this trade-off in the context of pharmaceutical bioequivalence, which is the primary quality standard for generic drugs....

This paper investigates the effect of endogenous horizontal product differentiation on trade patterns and the gains from trade under Bertrand and Cournot oligopoly. Firms differentiate their products to mitigate competition, but only if the investment required is not too high. Investment in...

This paper provides a new and simple model of endogenous horizontal product differentiation based on a standard demand structure derived from quadratic utility. One objective of the paper is to explain the "empirical Bertrand paradox" - the failure to observe homogeneous product Bertrand...

We consider nonparametric identification in models of differentiated products markets, using only market level observables. On the demand side we consider a nonparametric random utility model nesting random coefficients discrete choice models widely used in applied work. We allow for...

We develop a framework for studying trade in vertically and horizontally differentiated products. In our model, consumers with heterogeneous incomes and tastes purchase a homogeneous good as well as making a discrete choice of quality and variety of a differentiated product. The distribution of...

We show that demand uncertainty leads to vertical product differentiation even when consumers are homogeneous. When a firm anticipates that its inventory or capacity may not be fully utilized, product variety can reduce its expected costs of excess capacity. When the firm offers a continuum of...

Not surprisingly, big countries trade more than small countries. In this paper we use data on shipments by 110 exporters to 59 importers in 5,000 product categories to ask: how? Do big countries trade larger quantities of a common set of goods (the intensive margin), a larger set of goods (the...