It is hard to be enthusiastic about the economy's prospects when house prices are falling: Households spend less, small business owners can't use homes as collateral for loans and local governments are forced to cut jobs and programs as property-tax revenue disappears.

It has become fashionable to rail against government intervention in the economy, and the FHA is a favorite example by those trying to show the government's overreach. In reality, the FHA shows how government action during the Great Recession forestalled a much worse economic fate.

At the center of every recession is a serious imbalance in the economy and mirrored in the financial system. Think subprime mortgage and the Great Recession, or the technology bubble and the early 2000s recession. There are no such imbalances today.

If Mr. Trump gets precisely the policies he says he wants, then the economy will suffer a recession.

Potential home buyers have a two-step decision process. First, they determine whether they can afford to make a purchase - does their income safely cover their mortgage payment? Then they determine whether owning is a better financial choice than renting - are the costs of owning a home lower than the cost of renting it?

There is plenty of blame to go around for the U.S. housing bubble, but not much of it belongs to Fannie Mae and Freddie Mac. The two giant housing-finance institutions made many mistakes over the decades, some of them real whoppers, but causing house prices to soar and then crater during the past decade weren't among them.

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?