This paper develops a general equilibrium model of multi-product firms and analyzes their behavior during trade liberalization. Firm productivity in a given product is modeled as a combination of firm-level "ability" and firm-product-level "expertise", both of which are stochastic and unknown...

We document how demand shocks in export markets lead French multi-product exporters to re-allocate the mix of products sold in those destinations. In response to positive demand shocks, those French firms skew their export sales towards their best performing products; and also extend the range...

We examine the global operations of multi-product firms. We present a flexible heterogeneous-firm trade model with either limited or strong scope for quality differentiation. Using customs data for China during 2002-2006, we empirically establish that firms allocate activity across products in...

What accounts for the diversity and limited concentration that has long characterized the organization of the advertising agency industry? This question is addressed by treating an advertising agency as a multiproduct firm. The firm's product line or service mix is defined in terms of the set of...

We examine the interplay between market structure and the form that commodity taxation should take in a general equilibrium model in which firms produce differentiated products and so are able to exert market power. Our analysis takes account of two important recent developments that affect...

We analyze entry, pricing and product design in a model with differentiated products. Under plausible conditions, entry into an initially monopolized market leads to higher prices for some, possibly all, consumers. Entry can induce a misallocation of goods to consumers, segment the market in a...

In this paper I analyze the productivity gains from trade liberalization in the Belgian textile industry. So far, empirical research has established a strong relationship between opening up to trade and productivity, relying almost entirely on deflated sales to proxy for output in the production...

This paper examines the frequency, pervasiveness and determinants of product switching among U.S. manufacturing firms. We find that two-thirds of firms alter their mix of five-digit SIC products every five years, that one-third of the increase in real U.S. manufacturing shipments between 1972...

We consider a version of the imperfect competition model of Butters (1977), Varian (1980) and Burdett and Judd (1983) in which sellers make an ex-ante investment in the quality of their variety of the product. Equilibrium exists, is unique and is efficient. In equilibrium, search frictions not...