Trailer home borrowers, mostly near the bottom of the economic ladder, often default on their loans.

Like many other banks and finance companies, Green Tree used a process called securitization to resell its home loans to outside investors. Green Tree grouped thousands of these small loans into a pool worth hundreds of millions of dollars.

Most of America never noticed, but the 1990s were good times for trailer homes, a.k.a. manufactured housing. From 1991 to 1998, annual sales of manufactured homes more than doubled, to 374,000 from 174,000.

Climate change might be disastrous, but does that mean we want carbon taxes that raise the price of a gallon of heating oil to $10? And how exactly will those taxes affect economic growth?

To finance deficits, the government must sell bonds to investors, competing for capital that could otherwise be used to invest in stocks or corporate bonds. Government borrowings raise long-term interest rates, stifling economic growth.

Big companies often use their leverage to take stakes in would-be suppliers, especially in the technology business.