Americans have become increasingly segregated by income over the last 40 years. There are several causes, one of which is increasing income inequality. The middle class has been squeezed by deindustrialization, deunionization, tax cuts that favor the rich, the loss of their home equity, and other forces. And in addition to all that, I am wondering what role the real estate development industry has played in sorting us out by income. In particular, what role does the rise of CID housing play in this sorting process?