From Robert Samuelson, here:
". . . in poorer neighborhoods . . . the actual borrowers . . . were much richer than average residents. In 2002, home buyers in these poor neighborhoods had average incomes of $63,000, double the neighborhoods' average of $31,000. ...
"In 2002, the mortgage-debt-to-income ratio of the poorest borrowers was 2; in 2006, it was still 2. ...
"[T]he bulk of mortgage lending and losses [during the housing bubble] - measured by dollar volume - occurred among middle-class and high-income borrowers. In 2006, the wealthiest 40 percent of borrowers represented 55 percent of new loans and nearly 60 percent of delinquencies (defined as payments at least 90 days overdue) in the next three years."