Many studies have documented that the sales concentration of U.S. producers has risen in recent decades. In this article, we show that this increase was accompanied by more entry and growth of foreign competitors. Using confidential census data covering the universe of all firm sales in the U.S. manufacturing sector, we find that rising import competition increased concentration among U.S. firms by reallocating sales from smaller to larger U.S. firms and by causing firm exit. However, this increase in production concentration was counteracted by the expansion of foreign firms, which reduced domestic firms’ share of the U.S. market inclusive of foreign firms’ sales. We find that once the sales of foreign exporters are taken into account, U.S. market concentration in manufacturing was stable between 1992 and 2012.

How strong are strategic complementarities in price setting across firms? In this article, we provide a direct empirical estimate of firms’ price responses to changes in competitor prices. We develop a general theoretical framework and an empirical identification strategy, taking advantage of a new micro-level dataset for the Belgian manufacturing sector. We find strong evidence of strategic complementarities, with a typical firm adjusting its price with an elasticity of 0.4 in response to its competitors’ price changes and with an elasticity of 0.6 in response to its own cost shocks. Furthermore, we find evidence of substantial heterogeneity in these elasticities across firms. Small firms exhibit no strategic complementarities in price setting and complete cost pass-through. In contrast, large firms exhibit strong strategic complementarities, responding to both competitor price changes and their own cost shocks with roughly equal elasticities of around 0.5. We show that this pattern of heterogeneity in markup variability across firms is important for explaining the aggregate markup response to international shocks and the observed low exchange rate pass-through into domestic prices.