What Determines Entrepreneurial Clusters?
This research paper contrasts the effects of two factors in determining the rate of entrepreneurial activity across different regions: entry costs and local environment. The cost of starting a new business does not seem to be a factor in creating clusters of industry activity, however, knowledge spillovers and learning opportunities seem to be strong agents for growth.
Geography
Link
http://www.crenos.it/working/pdf/06-16.pdf