June 2010
Article
American Economic Review

What Causes Industry Agglomeration? Evidence from Coagglomeration Patterns

By: Glenn Ellison, Edward Glaeser and William R. Kerr

Format:Print
| Pages:19

Abstract

Why do firms cluster near one another? We test Marshall's theories of industrial agglomeration by examining which industries locate near one another, or coagglomerate. We construct pairwise coagglomeration indices for US manufacturing industries from the Economic Census. We then relate coagglomeration levels to the degree to which industry pairs share goods, labor, or ideas. To reduce reverse causality, where collocation drives input-output linkages or hiring patterns, we use data from UK industries and from US areas where the two industries are not collocated. All three of Marshall's theories of agglomeration are supported, with input-output linkages particularly important.

Keywords

Production; Economics; Industry Clusters; Data and Data Sets; Labor; Theory; Goods and Commodities; United States; United Kingdom

Citation

Ellison, Glenn, Edward Glaeser, and William R. Kerr. "What Causes Industry Agglomeration? Evidence from Coagglomeration Patterns." American Economic Review 100, no. 3 (June 2010): 1195–1213.

Supplemental Information

Mathematical Appendix to "What Causes Industry Agglomeration? Evidence from Coagglomeration Patterns"

In this mathematical appendix we discuss an index of coagglomeration introduced in Ellison and Glaeser (1997). We note that the index takes on a simpler form when used to measure pairwise coagglomeration. We further develop the economic motivation for the index as a measure of the importance of cross-industry spillovers and shared natural advantages.