I just had an insight I thought to share with you, one I have not seen belabored at length elsewhere. It has to do with European vs. American preferences for living inside or outside cities.
When you hear about poor and minority people in France living in suburbs or banlieues, not in run-down urban areas, haven't you wondered about how they happen to be on the fringes of cities? If you've traveled in France or Germany have you noticed farmers tend to live in the village and not on a corner of their farmland?
From all of this I conclude a sweeping generalization, that Europeans in general prefer to live in urban settings. When they think about what they'd aspire to if wealth came their way it is a spacious, luxurious apartment in a nice urban setting, close to everything.
This gentrifying preference pushes up the prices of in-town residences and forces the European poor and immigrant populations out of town as the less-desirable, cheaper places to live are on the scorned periphery.