We document several empirical regularities regarding the evolution of urban structure in the largest U.S. metropolitan areas over the period 1980-90. These regularities relate to changes in resident population, employment, occupations, as well as the number and size of establishments in...

We study the impact of regional and sectoral productivity changes on the U.S. economy. To that end, we consider an environment that captures the effects of interregional and intersectoral trade in propagating disaggregated productivity changes at the level of a sector in a given U.S. state to...

We study the impact of regional and sectoral productivity changes on the U.S. economy. To that end, we consider an environment that captures the effects of interregional and intersectoral trade in propagating disaggregated productivity changes at the level of a sector in a given U.S. state to...

We study empirically technology diffusion across countries and over time. We find significant evidence that technology diffuses slower to locations that are farther away from adoption leaders. This effect is stronger across rich countries and also when measuring distance along the south-north...

We use a comprehensive dataset of French manufacturing firms to study their internal organization. We first divide the employees of each firm into `layers' using occupational categories. Layers are hierarchical in that the typical worker in a higher layer earns more, and the typical firm...

We use a comprehensive dataset of French manufacturing firms to study their internal organization. We first divide the employees of each firm into `layers' using occupational categories. Layers are hierarchical in that the typical worker in a higher layer earns more, and the typical firm...

A firm's productivity depends on how production is organized. To understand this relationship we develop a theory of an economy where firms with heterogeneous demands use labor and knowledge to produce. Entrepreneurs decide the number of layers of management and the knowledge and span of control...

We develop a model of an economy where firms with heterogenous demands use labor and knowledge to produce. Managers of firms decide the optimal knowledge of its workers and managers, the number of layers of management, and the span of control of each agent. We use the model to analyze the effect...

The equilibrium relationship between trade and the spatial distribution of economic activity is fundamental to the analysis of national and regional trade patterns, as well as to the effect of trade frictions. We study this relationship using a trade model with a continuum of regions, transport...