[criddell]

For that to happen, living in a dense urban area needs to be much less expensive than living out in the middle of nowhere. The average income in Mississippi is around $25k / year. I'm not sure what the distribution curve looks like, but I'd guess 2/3 of the population make at least $20k / year. Cities should be designed so that a person can live a good life on $20k / year in a city.

[whimsicalism]

Yes, I agree. In many places, this is the case - but not in the US.

[criddell]

I'm trying to think of places where city living is significantly less expensive than living in more rural areas and about the only thing I can come up with are places where land is scarce and therefore expensive. For example, Hawaii.