This review discusses frontier topics in economic geography as they relate to firms and agglomeration economies. We … the vast scope for enhancements of our picture of agglomeration with the new data that are emerging …

This paper studies the sources of agglomeration economies in cities. We begin by introducing a simple dynamic spatial … large, though there can be exceptions. Thus, dynamic agglomeration appears to be driven by cross-industry effects. Once we … control for these cross-industry agglomeration effects, we find a strong negative relationship between city size and city …

localized spillover effects of the new parks on local incumbent firm productivity, the growth of retail activity close to the … parks featuring a higher level of human capital, a greater level of co-agglomeration among firms within the park, and a …

and policy analysis. A 'selection effect' means standard empirical measures overestimate agglomeration economies. A … 'sorting effect' means that a regional policy induces the highest productivity firms to move to the core while the lowest … productivity firms to move to the periphery. We also show that heterogeneity dampens the home market effect …

designed to attract firms to particular regions (place-based policies). I first propose a theory of the distribution of … heterogeneous firms in a variety of sectors across cities. Aggregate TFP and welfare depend on the extent of agglomeration …-level data. I find that nearly half of the observed productivity advantage of large cities is due to firm sorting. I use the …

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 particularly troublesome for identifying agglomeration effects: unobserved …

There is a strong connection between per worker productivity and metropolitan area population, which is commonly … interpreted as evidence for the existence of agglomeration economies. This correlation is particularly strong in cities with …

productivity …