This paper reconciles trade theory with plant-level export behavior by extending the Ricardian model to accommodate many countries, geographic barriers, and imperfect competition. The model captures key facts about U.S. plants: productivity dispersion, higher productivity among exporters, the small fraction who export, the small fraction of output earned from exports, and the size advantage of exporters. Using data on bilateral trade between the U.S. and 46 major trade partners, the authors examine the impact of globalization and dollar appreciation on productivity, plant entry and exit, and labor turnover in U.S. manufacturing. The paper introduces a model of international trade that explains producer-level facts, including heterogeneity in plant productivity, export participation, and size. The model incorporates three key elements: (1) technological efficiency differences across producers and countries, (2) costs of exporting through an "iceberg" assumption, and (3) imperfect competition with variable markups. The model links productivity, size, and export participation to technological efficiency, showing that more efficient producers tend to be more productive, larger, and more likely to export. The authors use the model to simulate the effects of globalization (a 5% drop in geographic barriers) and a decline in U.S. competitiveness (a 10% increase in relative wages) on plant entry, exit, exporting, employment, and productivity. Globalization reduces the number of U.S. plants by 3.3%, but increases the number of plants exporting. A decline in U.S. competitiveness reduces plant numbers by 3.1% and manufacturing employment by 13%, with some plants exiting entirely. The model shows that changes in the global economy can significantly reshape production, with important implications for overall manufacturing productivity. The paper also explores the relationship between plant-level facts and aggregate trade data, finding that the model can explain key features of U.S. plant-level data, including the productivity and size advantages of exporters. The model's parameters are estimated to match observed productivity and size advantages, and the model is shown to fit the data well in terms of export intensity, productivity variability, and size variability. The authors conclude that the model provides a useful framework for understanding the effects of trade on microeconomic outcomes, including plant-level productivity and export behavior.This paper reconciles trade theory with plant-level export behavior by extending the Ricardian model to accommodate many countries, geographic barriers, and imperfect competition. The model captures key facts about U.S. plants: productivity dispersion, higher productivity among exporters, the small fraction who export, the small fraction of output earned from exports, and the size advantage of exporters. Using data on bilateral trade between the U.S. and 46 major trade partners, the authors examine the impact of globalization and dollar appreciation on productivity, plant entry and exit, and labor turnover in U.S. manufacturing. The paper introduces a model of international trade that explains producer-level facts, including heterogeneity in plant productivity, export participation, and size. The model incorporates three key elements: (1) technological efficiency differences across producers and countries, (2) costs of exporting through an "iceberg" assumption, and (3) imperfect competition with variable markups. The model links productivity, size, and export participation to technological efficiency, showing that more efficient producers tend to be more productive, larger, and more likely to export. The authors use the model to simulate the effects of globalization (a 5% drop in geographic barriers) and a decline in U.S. competitiveness (a 10% increase in relative wages) on plant entry, exit, exporting, employment, and productivity. Globalization reduces the number of U.S. plants by 3.3%, but increases the number of plants exporting. A decline in U.S. competitiveness reduces plant numbers by 3.1% and manufacturing employment by 13%, with some plants exiting entirely. The model shows that changes in the global economy can significantly reshape production, with important implications for overall manufacturing productivity. The paper also explores the relationship between plant-level facts and aggregate trade data, finding that the model can explain key features of U.S. plant-level data, including the productivity and size advantages of exporters. The model's parameters are estimated to match observed productivity and size advantages, and the model is shown to fit the data well in terms of export intensity, productivity variability, and size variability. The authors conclude that the model provides a useful framework for understanding the effects of trade on microeconomic outcomes, including plant-level productivity and export behavior.