We use transaction-level data to study changes in the concentration of US imports. Concentration has fallen in the typical industry, while it is stable by industry and origin country. The fall in concentration is driven by the extensive margin: the number of exporting firms has grown, and the...

We use French data over the 1994-2013 period to study how imports of industrial robots affect firm-level outcomes. Compared to other firms operating in the same 5-digit sector, robot importers are larger, more productive, and employ a higher share of managers and engineers. Over time, robot...

We use transaction-level US import data to compare firms from virtually all countries in the world competing in a single destination market. Guided by a simple theoretical framework, we decompose countries' market shares into the contribution of the number of firm-products, their average...