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.

Housing was ground zero for the Great Recession. Between early 2006 and Obama's inauguration in 2009, average house prices fell by a third across the country. In certain areas, including cities as diverse as Akron, Orlando and Las Vegas, house prices fell by more than half.

The extension and expansion of the payroll tax holidays for workers would be number one on my list and key to avoiding recession.

Lenders look at potential borrowers from many angles before extending credit: How much of its income will a household need to put into debt repayment? How large is the down payment? Does the borrower have a job with a stable income? What is the borrower's credit score?

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.

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 FHA's success provides strong evidence that government can and should play a role in the nation's mortgage finance system. It also demonstrates that although government intervention in the economy during the Great Recession was messy, things would have been a lot messier without it.