This paper develops a model of endogenous product selection by firms. The theory is motivated by new evidence we present on the importance of product switching by U.S. manufacturers. Two-thirds of continuing firms change their product mix every five years, and product switches involve more than...

Merged firms are typically rather complex organizations. Accordingly, merger has a more profound effect on the structure of a market than simply reducing the number of competitors. We show that this may render horizontal mergers profitable and welfare-improving even if costs are linear. The...

New empirical and theoretical work has highlighted the importance of multi-product firms in international trade flows. We examine multi-product exporters in the small open economy of Belgium, considering their importance and the relationship between the margins of trade and firm productivity,...

This paper explores role of multi-product plants and product switching in the Japanese manufacturing sector. While a substantial body of work has explored the importance of the extensive margins of plant entry and exit in employment and output flows, only recently has research begun to examine...

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...

This paper examine multi-product exporters in Belgium, considering their importance and the relationship between the margins of trade and firm productivity. We employ proxies for trade costs to quantify the extensive and intensive margin adjustments of trade. Relatively few exporting firms...

This paper examines the frequency, pervasiveness and determinants of product switching by U.S. manufacturing firms. We find that one-half of firms alter their mix of five-digit SIC products every five years, that product switching is correlated with both firm- and firm-product attributes, and...