Economists widely agree that the effects of a debt default 鈥 or even of the Treasury failing to meet billions of dollars in ordinary obligations 鈥 would be swift and severe. It鈥檚 hard to know just how severe because, again, this hasn鈥檛 been tested before by the world鈥檚 leading economy.
Interest rates would rise as investor confidence is shaken, and the Treasury would face the prospect of downgrades by credit-rating firms. The squeeze on federal spending (imposed by the borrowing cap) would deal a blow to economic activity equaling about 4 percent of GDP, some forecasters estimate.
The stock market could plunge, and consumer confidence along with it.
The toll in the US would have global fallout as well, pushing up interest rates and squeezing economic growth.
Even if Congress goes near this cliff and then raises the debt limit by Oct. 17, the brinkmanship could have noticeable consequences. In 2011, when Congress got close to the edge before cutting a deal, Standard & Poor鈥檚 gave US sovereign debt a downgrade. Mortgage costs jumped and consumer confidence sagged. Stock prices overseas fell alongside US stocks.