I think two factors - high productivity leads to high cost of living, which means people without labor skills have a hard time making enough money for food and

I think two factors - high productivity leads to high cost of living, which means people without labor skills have a hard time making enough money for food and shelter. But ALSO - these areas tend to lean towards higher levels of social services such that they have much higher homeless shelter / services / etc per capita. So while many people may go homeless in place, certainly there is some homeless migration towards areas that actually provide food/shelter and don't harass/arrest them/chase them away.