Distressed properties are often vacant and in disrepair, and thus sold at significant discounts. As the share of distressed sales grows, home prices fall.

Global central banks are working hard to lift their economies through an aggressively easy monetary policy. The ECB [European Central Bank] and BOJ [Bank of Japan] are buying tens of billions of bonds and other financial securities each month in an effort to stimulate their economies, which is pushing down rates everywhere, including in the U.S.

A housing renaissance has begun. This may be hard to believe after the dizzying, six-year-long crash in home sales, construction and house prices. But housing turned the corner last year, and it will take off in 2013.

The upshot of Mr. Trump's economic policy positions under almost any scenario is that the U.S. economy will be more isolated and diminished.

The Tea Party was born out of the disgust many Americans felt early in the financial crisis upon learning that the federal government was even contemplating reducing the principal on some troubled mortgages.

Indeed, the FHA was born out of the Great Depression, which was also caused in significant part by a foreclosure crisis. Mortgages in the early 1930s were mostly three- to five-year 'bullet' loans, which did not amortize and were due in full at maturity.

Too-easy credit and millions of bad loans made during the U.S. housing bubble paved the way for the financial calamity and Great Recession that followed. Today, by contrast, credit is too tight. Mortgage loans are particularly hard to get, creating a problem for the housing market and the broader economy.