It's quite common for people to reach child-raising or retirement age and move to such places, or even leave their families there and continue to work in the bi

It's quite common for people to reach child-raising or retirement age and move to such places, or even leave their families there and continue to work in the big city. These cities also tend to have a lot of cottage-industry scale businesses: the average small American town is probably the worldwide capital of some incredibly obscure product or service. A town needs hard-currency inflow to pay for their imports but not a terribly large amount of it.