Where Segregation Has Worsened the Housing Divide - CityLab:
Over the last two decades, America has become increasingly polarized by both class and geography. As the middle class and its neighborhoods have declined, our nation has increasingly divided into rich and poor, and neighborhoods of concentrated affluence have become surrounded by larger spans of concentrated disadvantage.
This pattern is both reflected and reinforced by housing prices. An analysis released today by the real estate company Trulia finds considerable overlap between racial segregation and polarization of housing values across America’s 100 largest metropolitan areas.
Gated communities in particular, and CIDs in general, seem to have contributed to income segregation. They are usually targeted narrowly to certain bands of the income distribution, and their enforced uniformity in design, etc., caters to common tastes and lifestyles.