The paper by Bernard, Eaton, Jensen, and Kortum reconciles trade theory with plant-level export behavior, extending the Ricardian model to accommodate multiple countries, geographic barriers, and imperfect competition. The model captures key facts about U.S. plants, such as productivity dispersion, higher productivity among exporters, the small fraction of plants that export, the small fraction of output earned from exports, and the size advantage of exporters. The authors fit the model to bilateral trade data between the United States and 46 major trade partners to examine the impact of globalization and dollar appreciation on productivity, plant entry and exit, and labor turnover in U.S. manufacturing. The model links observed variations in productivity, size, and export participation to underlying differences in technological efficiency. It explains why more efficient plants tend to be more productive, larger, and more likely to export. The model also predicts that changes in the global economy, such as a 5% drop in geographic barriers or a 10% increase in the U.S. relative wage, can significantly affect plant entry, exit, exporting, employment, and productivity. The authors use counterfactual experiments to illustrate these effects, showing that even in a large market like the United States, changes in the global economy can reshuffle production and have important implications for overall manufacturing productivity.The paper by Bernard, Eaton, Jensen, and Kortum reconciles trade theory with plant-level export behavior, extending the Ricardian model to accommodate multiple countries, geographic barriers, and imperfect competition. The model captures key facts about U.S. plants, such as productivity dispersion, higher productivity among exporters, the small fraction of plants that export, the small fraction of output earned from exports, and the size advantage of exporters. The authors fit the model to bilateral trade data between the United States and 46 major trade partners to examine the impact of globalization and dollar appreciation on productivity, plant entry and exit, and labor turnover in U.S. manufacturing. The model links observed variations in productivity, size, and export participation to underlying differences in technological efficiency. It explains why more efficient plants tend to be more productive, larger, and more likely to export. The model also predicts that changes in the global economy, such as a 5% drop in geographic barriers or a 10% increase in the U.S. relative wage, can significantly affect plant entry, exit, exporting, employment, and productivity. The authors use counterfactual experiments to illustrate these effects, showing that even in a large market like the United States, changes in the global economy can reshuffle production and have important implications for overall manufacturing productivity.