This article describes methods used in the field of spatial economics that combine insights from economic theory and evidence from data in order to answer counter- factual questions. I outline a general framework that emphasizes three elements: a specific question to be answered, a set of...

Considerable progress has been made in our understanding of the relationship between international trade and the environment since Gene Grossman and Alan Krueger published their now seminal working paper examining the potential environmental effects of the North American Free Trade Agreement in...

How does the interplay of geography and political-economic forces affect the shape of nations? This paper presents a quantitative framework for characterizing the equilibrium evolution of national boundaries in a world with a rich geography. The framework delivers simple equilibrium conditions...

One account of spatial concentration focuses on productivity advantages arising from market size. We investigate this for forty regions of Japan. Our results identify important effects of a region's own size, as well as cost linkages between producers and suppliers of inputs. Productivity links...

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...

When economic activity is concentrated over space or over time, it is more efficient. Most production occurs in geographic hot spots, and most production occurs between 9 and 12 in the morning and 1 to 5 in the afternoon on weekdays. The thick-market efficiencies that encourage the concentration...

Information technology (IT) matters to prosperity. The top patenters are increasingly IT companies. We use data on US patents to document four trends in IT patenting. First, firm-level concentration in IT patenting is increasing over time. Second, geographic concentration in IT patenting is...