Philip Greenspun:

On our trip through Kansas, it was impossible not to notice the difference in average intelligence between Lawrence, the university town, and Liberal, a beef-processing and Walmart town.  In 1900, the costs of moving away from one's home town were high.  You'd see your family and friends only once every year or two.  You'd talk on the phone or communicate via telegraph only in an emergency.  These costs discouraged enough folks from moving that every town had its intellectuals.  They dreamed of moving to Manhattan, but they never did.  You'd find them at the library, in the local theater company, running a Great Books club, etc.

There's some truth to that - a related thing occurred to me while reading about the flue epidemic (1918) last night. The civic associations that took over when local government failed were all run by women; most of the women who ran civic organizations then have jobs now. Social change has many interesting side effects - but back to Greenspun's point. Further down, he makes a point that I think works against his theory over the long haul:

In 2006, you can move 300 miles away and get back home every weekend on an Interstate highway in a few hours.  You can move 2000 miles away and get back home every month for $300 round-trip on an airliner.  For a fixed $20 per month, you can get a voice-over-IP phone and make unlimited long-distance calls.  For free, you can exchange email and instant messages.  You can get the benefits of moving, associating with other smart interesting people, without many of the costs formerly imposed on those who moved away from their home towns.

That same technology allows a lot of smart people to move to "dumb" lower cost areas, and still work with the "smart" people. Consider - I live in suburban Maryland. Existing homes in my area are going for $750k and up. We don't live near a river or the ocean, either. My sister lives in suburban Texas. Down there, she and her husband were able to afford a house on one income. Heck, when I look at housing prices in Ohio, near where Cincom headquarters is, I get shocked - the prices there are less than half what they are here, and the weather is no worse. I'm in my forties, and established - but believe me, if I were 24, and just starting out - there's no way I could even begin to afford living in my area. That reality, combined with the technology advances in communication, are going to have distributive effects of their own.