From an article in the May 24, 2014 issue of The Economist about how racial minorities in the United States live in places where they breathe dirtier air:
[…]The study does not address why [race matters more than income in determining whether someone will live exposed to dirtier air]. A possible explanation is that many Americans prefer to live among people who look like themselves. For example, well-off urban blacks may be choosing to live in traditionally black neighbourhoods, despite the worse air and the fact that they could afford to live elsewhere.
A slight re-write of the paragraph above:
[…]The study does not address why [race matters more than income in determining whether someone will live exposed to dirtier air]. A possible explanation is that people prefer to live where they will be treated like fellow human beings. For example, well-off urban blacks may be choosing to live in traditionally black neighbourhoods, despite the worse air and the fact that they could afford to live elsewhere.
The latter paragraph tells a different story; a story readers of The Economist need to hear.