The standard approach to studying industrial agglomeration is to construct summary measures of the degree of agglomerationʺ within each industry and to test for significant agglomeration with respect to some appropriate reference measures. But such summary measures often fail to distinguish...

In estimating the production function of firms, problems of endogeneity and self selection exist as a result of firm-specific productivity shocks and entry/exit decisions. Several methods have been proposed to handle these problems, such as those by Olley and Pakes (1996) and Levinsohn and...

Numerous studies have indicated that densely populated cities enhance the productivity of workers through knowledge spillover and superior matching with employers in the labor market. This paper quantitatively analyzes the relationship among urban density, human capital, and wages by using micro...

In this paper, I explain Thünens pioneering work on industrial agglomeration. In my opinion, Thünens thinking on industrial agglomeration was not only amazingly advanced for his time, but in many respects remains novel even today. It is shown that if we unify Thünens well-known theory on...

The spatial structure of transport networks is subject to increasing returns in transportation, distance, and density economies. Transport costs between locations are thus, in general, endogenous, and are determined by the interaction between the spatial distribution of transport demand and...