Decomposing Aggregate Trade Flows: New Evidence from U.S. Traders

Using firm-level data on export transactions, we uncover a rich set of results about the extensive margins of exporting and exporter responses during periods of global downturns. We perform our analysis with respect to firm size, age, ownership status, and sector to emphasize the role of firm heterogeneity. We uncover a larger role for firm entry and exit in changes in annual export flows of single-unit, smaller, and younger firms. Young, small firms perform best during both periods of crises as well as non-crises periods. We also decompose the margins of U.S. imports at the U.S. importer, foreign supplier, and U.S. importer-foreign supplier pair levels. While export flows are closely correlated with global business cycles, import flows more closely approximate U.S. economic cycles. Additionally, both pair and foreign supplier flows are far more volatile than U.S. import flows, that is, U.S. importer-foreign supplier matches experience more churning on average than do either U.S. importers or foreign suppliers.