We study the role of firm heterogeneity and imperfect competition for global production networks and the gains from trade. We develop a quantifiable trade model with two-sided firm heterogeneity, matching frictions, and oligopolistic competition upstream. More productive buyers endogenously match with more suppliers, thereby inducing tougher competition among them to enjoy lower input costs and superior performance. Transaction-level customs data confirms that downstream French and Chilean firms import higher values and quantities at lower prices as upstream Chinese markets become more competitive over time, with stronger responses by larger firms. Moreover, suppliers charge more diversified buyers lower mark-ups. Counterfactual analysis indicates that entry upstream benefits high-productivity buyers, while lower matching or trade costs benefit all buyers, with the biggest boost to mid-productivity buyers. All three shocks generate sizeable welfare gains, especially under package reforms. Global production networks thus mediate bigger effects and cross-border spillovers from industrial and trade policies.

This paper examines the impact of the carbon emissions trading scheme (ETS) on directed technological change in the context of Chinese pilot schemes. We focus on firms’ heterogeneity in driving innovation and explore policy variations across pilots. Using a matched difference-in-differences design with a zero-inflated Poisson model, we find that the low-carbon innovation is driven by firms at the intensive margin. On average, a firm files 0.16 additional low-carbon patents annually at the intensive margin. In addition, when looking across pilots, the effect on low-carbon innovation is significant in two pilots, Beijing and Shanghai. We further find that, when looking at firms with different productivity levels measured by output per worker, the pilot ETS encourages low-carbon innovation at the intensive margin but reduces entry into low-carbon innovation at the extensive margin for the more productive firms. Our results suggest that innovation inertia matters, and future policies should encourage smaller firms covered by ETS to start innovation in low-carbon technologies.