Shaila Dewan, writing for the New York Times:
Khadeja may have paid more to borrow, but she was also buying a service — being forced to pay. Most of us already make constant use of this service, managing our money by borrowing and saving at the same time. In 2000, two business-school professors found that 90 percent of Americans with credit-card debt also had liquid assets, and about a third of them had enough to pay off the entire debt. But they didn’t. One reason is that if you spend your savings, you’re back to zero quickly. So you may prefer to pay a little more to borrow while keeping something in reserve.
Interesting social theory there.