Cities vary with regard to the characteristics of their economic life. A formal model by Duranton and Puga (2001) suggests a division of labour between diversified and specialized cities. Diversified cities (the “nursery cities”) provide a fertile environment for search and innovation....

In this paper, the changing roles of agglomeration externalities during different stages of the industry life cycle are investigated. A central argument is that agglomeration externalities vary with mode of competition, innovation intensity, and characteristics of learning opportunities in...

We study localization, urbanization, and Jacobs' externality effects on plant survival inSweden (1970-2004). We focus on two questions: (1) do agglomeration externalities changewith the age of plants? (2) using new information about the relatedness among industries,what is the role of...