We reconcile international trade theory with findings of enormous plant-level heterogeneity in exporting and productivity. Our model extends basic Ricardian theory to accommodate many countries, geographic barriers, and imperfect competition. Fitting the model to bilateral trade among the United...

European countries do less research than Japan and the United States. We use a quantitative multi-country growth model to ask: (i) Why is this so? (ii) Would there be any benefit to expanding research in Europe? (iii) What would various European research promotion policies do? We find that (i)...

Innovative activity is highly concentrated in a handful of advanced countries. These same countries are also the major exporters of capital goods to the rest of the world. We develop a model of trade in capital goods to assess its role spreading the benefits of technological advances. Applying...

We examine the sales of French manufacturing firms in 113 destinations, including France itself. Several regularities stand out: (1) the number of French firms selling to a market, relative to French market share, increases systematically with market size; (2) sales distributions are very similar...

We model the invention of new technologies and their diffusion across countries. Our model predicts that, eventually, all countries will grow at the same rate, with each country's productivity ranking determined by how rapidly it adopts inventions. The common growth rate depends on research...

We develop and estimate a model of technological innovation and its contribution to growth at home and abroad. International patents indicate where innovations come from and where they are used. Countries grow at a common steady-state rate. A country's relative productivity depends upon its...

A recent literature has introduced heterogeneous firms into models of international trade. This literature has adopted the convention of treating individual firms as points on a continuum. While the continuum offers many advantages this convenience comes at some cost: (1) Shocks to individual...

Global trade fell 30 percent relative to GDP during the Great Recession of 2008-2009. Did this collapse result from factors impeding international transactions or did it simply reflect the greater severity of the recession in highly traded sectors? We answer this question with detailed...

We develop a Ricardian model to explore the role of trade in spreading the benefits of" innovation. The theory delivers an equation for bilateral trade that gravity specification, but identifies underlying parameters of technology. We estimate the" equation using trade in manufactures among the...

We examine entry across 113 national markets in 16 different industries using a comprehensive data set of French manufacturing firms. The data are unique in indicating how much each firm exports to each destination. Looking across all manufacturers: (1) Firms differ substantially in export...