Americans are finally stashing more money away—and that’s a bad thing.

Just how much the lenders will retrench is, if not exactly anybody's guess, an opaque and technical subject. Nouriel Roubini thinks that the fall in lending—that enforced savings—can cut consumer spending by 4 percent this year and 8 percent next year: a total of $1.2 trillion, more than enough to swallow up all the tax cuts and stimulus checks that the government is trying to throw at the problem. Hopefully the number will be lower. We just have no good way of knowing.

What we do know is that the savings crisis that policymakers and economists ignored in the middle of the decade threatens to clobber the economy next year. What looked like a long-term problem of how we will find the future of American retirement has turned into a pressing, immediate problem of how we can raise the money to get out of the jam we're in. We have a recession on our hands, worse than anything we've seen since at least the ‘50s, and suddenly the usual response to recessions—lowering our savings—just isn't an option. We all know that having savings is a good thing for some indefinite time in the future. But even the people who warned us about the savings crisis didn't think that future would arrive this soon.