The NYT reports on a new set of papers from the IMF, one of which warns that many wealthy countries, including the United States, are very close to the limit of their ability to increase their national debt. It is worth noting that this paper's methodology indicated that Japan and Italy were already well above the limit of their ability to take on debt.
The financial markets apparently assess the situation differently than the IMF since both countries are still able to issue long-term debt at very low interest rates. The fact that the methodology is apparently quite wrong in predicting the situations faced by these two countries might suggest that it is not a very useful methodology for guiding U.S. policy.
It is also worth noting that IMF somehow did not see the $8 trillion housing bubble that wrecked the U.S. economy, nor the bubbles in Spain, Ireland, and the U.K. There have been no obvious changes in the IMF's structure that would lead one to believe that it is better at assessing economic prospects today than it was three years ago.