Firms and workers are much more productive in large and dense urban environments. There is substantial evidence of such agglomeration economies based on three aproaches. First, on a clustering of production beyond what can be explained by chance or comparative advantage. Second, on spatial...

Increasingly, a small number of low-wage countries such as China and India are involved in incremental innovation. That is, they are responsible for resolving production line bugs and suggesting product improvements. We provide evidence of this new phenomenon and develop a model in which there...

This paper deals with the effects of cross-border transport infrastructure in the presence of agglomeration economies. Cross-border infrastructure is more likely to increase than to decrease inequalities between and within regions, and has not helped regional convergence in Europe....

Firms are more productive on average in larger cities. Two explanations have been offered: agglomeration economies (larger cities promote interactions that increase productivity) and firm selection (larger cities toughen competition allowing only the most productive to survive). To distinguish...

There is controversy about whether geography matters mainly because of its contemporaneous impact on economic outcomes or because of its interaction with historical events. Looking at terrain ruggedness, we are able to estimate the importance of these two channels. Because rugged terrain hinders...

We study the relationship between urban sprawl and obesity. Using data that tracks individuals over time, we find no evidence that urban sprawl causes obesity. We show that previous findings of a positive relationship most likely reflect a failure to properly control for the fact the individuals...

This paper decomposes the growth in land occupied by residences in the United States to give the relative contributions of changing demographics versus increases in the land area used by individual households. Between 1976 and 1992 the amount of residential land in the United States grew 47.5%...

We provide empirical evidence on the role of labour market pooling in determining the spatial concentration of UK manufacturing establishments. This role arises because large concentrations of employment iron out idiosyncratic shocks and improve establishments\' ability to adapt their employment...