The density of smart people?

I think this is fascinating

It’s becoming increasingly accepted that there is real economic value to bringing a lot of smart and entrepreneurial people together in the same place. This can be tough to measure, unfortunately. Perhaps best proxy we have available is educational attainment – usually measured as the number of people in a particular place with bachelor’s degrees or higher, as reported by the Census Bureau.

http://blog.robpitingolo.org/2010/05/where-smart-people-live.html

I’m not sure that this is true, that you really need density, because density is not the way humans interact. We interact with networks of social contacts, now if you virtualize contacts or if you have a higher network density, that means less people but they are better connected you might be able to compensate a lower overall density.