Supply chain risk hampers the gains from globalization and requires costly resilience investments. I show that specialized intermediaries help firms mitigate disruptions, offering an alternative to managing risk directly. Combining customs and tax records from Chile, I document that the share of intermediated imports rises with origin-product risk, as intermediaries maintain more diversified and robust supply networks. These facts motivate a model of global sourcing with costly supplier matching, insecure supply relationships, and intermediation services. Heterogeneous producers balance input prices and disruption probabilities across origins to minimize expected production costs. More productive firms match with multiple suppliers in risky locations, while less productive firms contract with intermediaries, paying a markup for a more resilient network. Model quantification reveals that, despite higher input prices, intermediation relaxes the efficiency–risk trade-off for producers that lack the scale to diversify. Intermediation is thus instrumental for the resilience of smaller firms in global markets.

This paper examines intermediation in production networks to unpack the firm attributes and matching costs that govern firm-to-firm networks and the gains from trade. Exploiting rich customs data for Chile, we show that exporters of all sizes use intermediaries, mix trade modes across buyers, and set lower prices on intermediated flows. We rationalize these facts in a model of network formation with suppliers of heterogeneous productivity and matchability, buyers of heterogeneous productivity, and intermediaries that reduce matching costs for a brokerage fee. Empirical evidence on trade activity across firms and countries corroborates the model, and informs how geographic distance, logistics and customs efficiency, formal institutions, and cultural-linguistic similarity shape network costs. Model estimation reveals that sellers’ attributes are negatively correlated, such that intermediaries enable highly productive sellers with low matchability to reach smaller buyers. This amplifies the welfare gains from intermediation due to wider and deeper network connectivity.

How do global production networks and market structure interact to shape the gains from trade and competition policy? We develop a quantifiable model with two-sided firm heterogeneity, matching frictions, and imperfect competition. More productive buyers match with more suppliers, which spurs tougher competition, lowers input costs, and raises profits. Reduced-form evidence confirms that larger French and Chilean firms import higher quantities at lower prices as more Chinese suppliers enter, and that suppliers charge diversified buyers lower markups. We estimate the model by extending recent methods for combinatorial discrete-choice problems. Counterfactuals reveal that entry upstream benefits primarily high-productivity buyers, while lower trade or matching costs favor mid-productivity firms. Moreover, the interaction between endogenous networks and markups significantly amplifies the welfare gains from entry upstream, as well as from packaging trade liberalization with reductions in matching or entry costs.

This paper studies the role of customer portfolio management in exporters' growth. Using panel data on Chilean exporters and their foreign buyers (2002–2019), we document new facts on export dynamics. Growing exporters replace old customers with more profitable matches, accounting for nearly 40% of firms' export growth, while increasing both their average price and price dispersion across customers. We build a dynamic model of exporting with endogenous network formation, managerial costs of customer relationships, and bilateral bargaining that can rationalize these patterns. Each period, firms decide how much to invest in customer search, which customers to retain, and what prices to charge. Additional customers enhance exporters' sales and negotiating positions, but they also increase managerial costs. Using the model, we characterize firms' dynamic export strategies and quantify the role of managerial costs in export growth. We then evaluate policies that reduce search and managerial costs, considering both individual and combined reforms, and their interaction with policies that increase competition through market entry.