The paper examines the factors contributing to the greater exports of larger economies, using data on shipments from 126 exporting countries to 59 importing countries in 5,000 product categories. The authors find that the extensive margin (the variety of goods exported) accounts for about 60% of the greater exports of larger economies, while the intensive margin (the quantity of each good exported) is dominated by higher quantities rather than higher unit prices. Richer countries export higher quantities of each good at modestly higher prices, consistent with higher quality. Countries with more workers export higher quantities of each good, but not at higher prices. These findings are inconsistent with Armington models, which predict no extensive margin and lower export prices for larger economies. Krugman-style models with firm-level product differentiation predict a prominent extensive margin but overpredict the rate at which variety responds to exporter size. Quality differentiation models can better explain the price facts. The authors also suggest that fixed costs of exporting to a given market might explain why larger economies export to more countries. The paper concludes by discussing the implications of these findings for trade theories and welfare effects.The paper examines the factors contributing to the greater exports of larger economies, using data on shipments from 126 exporting countries to 59 importing countries in 5,000 product categories. The authors find that the extensive margin (the variety of goods exported) accounts for about 60% of the greater exports of larger economies, while the intensive margin (the quantity of each good exported) is dominated by higher quantities rather than higher unit prices. Richer countries export higher quantities of each good at modestly higher prices, consistent with higher quality. Countries with more workers export higher quantities of each good, but not at higher prices. These findings are inconsistent with Armington models, which predict no extensive margin and lower export prices for larger economies. Krugman-style models with firm-level product differentiation predict a prominent extensive margin but overpredict the rate at which variety responds to exporter size. Quality differentiation models can better explain the price facts. The authors also suggest that fixed costs of exporting to a given market might explain why larger economies export to more countries. The paper concludes by discussing the implications of these findings for trade theories and welfare effects.