U.S. Government Default?

Greg Ip reports:

Thanks to the advent of credit derivatives -- financial contracts that allow investors to speculate on or protect against default -- we can now observe how likely global markets think it is that Uncle Sam will renege on America's mounting debts. Last week, markets pegged the probability of a U.S. default at 6 percent over the next 10 years, compared with just 1 percent a year ago.