Tech clusters like Silicon Valley play a central role for modern innovation, business competitiveness, and economic performance. This paper reviews what constitutes a tech cluster, how they function internally, and the degree to which policy makers can purposefully foster them. We describe the...

We use new theory and data to study how firms endogenously form production networks across regions and countries. Supplier and buyer relationships form depending on firms' productivity and geographic location. We characterize the normative and positive properties of the spatial distribution of...

The growth of high-technology clusters in the United States suggests the presence of strong regional agglomeration effects that reflect proximity to universities or other research institutions. Using data on licensed patents from the University of California, Stanford University, and Columbia...

We consider the distribution of economic activity within a country in light of three leading theories - increasing returns, random growth, and locational fundamentals. To do so, we examine the distribution of regional population in Japan from the Stone Age to the modern era. We also consider the...

This paper studies localization of academic and industrial knowledge spillovers. Using data on U.S. Research and Development laboratories, that quantify spatial aspects of learning about universities and firms as well as their locations, I find that academic spillovers are more localized than...

Convergence in per capita income turns on whether technological knowledge spillovers are global or local. Global spillovers favor convergence, while a geographically limited scope of knowledge diffusion can lead to regional clusters of countries with persistently different levels of income per...

In recent empirical literature on spatial agglomeration, many papers find evidence consistent with location-specific externalities of some sort. Our willingness to accept evidence of agglomeration economies depends on how well key estimation problems have been addressed. Three issues are...

Convergence in per capita income across countries turns on whether technological knowledge spillover are global or local. This paper estimates the amount of spillover from R&D expenditures in major industrialized countries on a geographic basis. A new data set is used which encompasses most of...

Does regional economic integration affect the location of economic activity inside countries? In this paper, I discuss recent academic literature on whether the movement towards free trade in North America has influenced the spatial organization of production in Canada, Mexico, or the United...