It's important here to differentiate between the big cities and the next tier. The big, dense cities (SF, NYC, Boston, London, Tokyo, etc) have accumulated wea

It's important here to differentiate between the big cities and the next tier. The big, dense cities (SF, NYC, Boston, London, Tokyo, etc) have accumulated wealth and privilege within the city and lower income folks are on the perimeter. In second tier cities, it's more common for suburban sprawl to have led to "white flight" and wealth accumulation outside city centers... but those cities frequently don't have near the economic draw in their downtowns anyway so it doesn't matter.