Economists have long suspected that firm-to-firm relationships might lower the responsiveness of prices to shocks due to the use of fixed-price contracts. Using transaction-level U.S. import data, I show that the pass-through of exchange rate shocks in fact rises as a relationship ages. Based on novel stylized facts about a relationship's life cycle, I develop a model of relationship dynamics in which a buyerseller pair accumulates relationship capital to lower production costs under limited commitment. The structurally estimated model generates countercyclical mark-ups and countercyclical pass-through of shocks through variation in the economy's rate of relationship creation, which falls in recessions.

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.

We study the effect of risk on how firms organize their supply chains. We use transaction-level data on U.S. manufacturing imports to construct a novel measure of input sourcing risk based on the historical volatility of ocean shipping times. Our measure isolates the unexpected component of shipping times that is induced by weather conditions along more than 331,000 maritime routes. We first document that unexpected shipping delays significantly reduce importers’ sales, profits, and employment. We then show that firms actively diversify weather risk by using more routes and foreign suppliers, although their import values decline. To rationalize these findings, we introduce shipping time risk into a general equilibrium model of importing with firm heterogeneity. Our quantitative analysis predicts substantial costs for the U.S. economy associated with supply chain risk.