We estimate a structural model of heterogeneous multiproduct firms to examine the sources of firm heterogeneity emphasized in the recent trade and macro literatures. Using Nielsen barcode data on prices and sales, we estimate elasticities of substitution within and between firms, and use the...

This paper extends a recent class of quantitative models of international trade to incorporate factor mobility within countries. We present a model-based decomposition of the variance of economic activity into the contributions of locational fundamentals, market access and their covariance. We...

This paper reviews the empirical evidence on firm heterogeneity in international trade. A first wave of empirical findings from micro data on plants and firms proposed challenges for existing models of inter- national trade and inspired the development of new theories emphasizing firm...

This paper develops a quantitative model of city structure to separate agglomeration forces, dispersion forces and fundamentals as determinants of location choices. The model remains tractable and amenable to empirical analysis because of stochastic shocks to worker productivity, which yield a...

We develop a new methodology for quantifying the tasks undertaken within occupations using 3,000 verbs from around 12,000 occupational descriptions in the Dictionary of Occupational Titles (DOTs). Using micro-data from the United States from 1880-2000, we find an increase in the employment share...

We examine how firm heterogeneity influences aggregate welfare through endogenous firm selection. We consider a homogeneous firm model that is a special case of a heterogeneous firm model with a degenerate productivity distribution. Keeping all structural parameters besides the productivity...

The theoretical result that there are welfare gains from trade is a central tenet of international economics. In a class of trade models that satisfy a "gravity equation," the welfare gains from trade can be computed using only the open economy domestic trade share and the elasticity of trade...

This paper uses the natural experiment of Argentina's integration into world markets in the late-nineteenth century to provide evidence on the role of internal geography in shaping the effects of external integration. We develop a quantitative model of the distribution of economic activity...

This paper surveys the theoretical and empirical literature on the relationship between the spatial distribution of economic activity and transportation costs. We develop a multi-region model of economic geography that we use to understand the general equilibrium implications of transportation...

This paper reviews the new approach to international trade based on firm heterogeneity in differentiated product markets. This approach explains a variety of features exhibited in disaggregated trade data, including the higher productivity of exporters relative to non-exporters, within-industry...