Earlier quoted context omitted.
The big metros are more efficient (dollar-wise) and have a lower environmental impact than small towns. Small towns, in the US, are already subsidized by big towns, at least economically.
> and have a lower environmental impact than small towns Can you expand on that (or link to more) ?
A cursory glance shows that the densest urban centers have the lowest carbon footprint. The suburbs are much higher, with affluent suburbs often being more than twice as high. Only some very rural areas approach levels as low as the cities.