Trade costs, firms and productivity $
This paper examines the response of U.S. manufacturing industries and plants to changes in trade costs using a unique new dataset on industry-level tariff and transportation rates. Our results lend support to recent heterogeneous-firm models of international trade that predict a reallocation of economic activity towards high-productivity firms as trade costs fall. We find that industries experiencing relatively large declines in trade costs exhibit relatively strong productivity growth. We also find that low-productivity plants in industries with falling trade costs are more likely to die; that relatively high-productivity non-exporters are more likely to start exporting in response to falling trade costs; and that existing exporters increase their shipments abroad as trade costs fall. Finally, we provide evidence of productivity growth within firms in response to decreases in industry-level trade costs.