Clustering is the driving force of today’s post-industrial economy, evident in the cramming and jamming of techies in the Bay Area, media types in Los Angeles, and finance workers in New York City.
Even these knowledge-based industries require large institutions of some kind to root them in place. Tech hubs grow around great universities, companies such as Google or Amazon, and abundant venture capital. Hollywood has its major studios and filmmaking complexes. New York has the big banks and financial firms of Wall Street.