> McDonalds pays more or less the same whether you are in the big city or in a small town.
...partially adjusted for local cost of living, of course. https://en.wikipedia.org/wiki/Balassa-Samuelson_effect Which means that, yes, staying in the city is generally a bad deal for a low-productivity worker in the non-tradable sector. But not as much of a bad deal as it would be if those wage variations did not exist. And they might be able to make up for it and even come out ahead by being super frugal and saving most of their income (this is the archetypical "unskilled immigrant to a rich area" story).
...partially adjusted for local cost of living, of course. https://en.wikipedia.org/wiki/Balassa-Samuelson_effect Which means that, yes, staying in the city is generally a bad deal for a low-productivity worker in the non-tradable sector. But not as much of a bad deal as it would be if those wage variations did not exist. And they might be able to make up for it and even come out ahead by being super frugal and saving most of their income (this is the archetypical "unskilled immigrant to a rich area" story).