官方证实：美国经济于去年底正式进入衰退。

WASHINGTON - A panel of the National Bureau of Economic Research said Monday that the U.S. economy fell into a recession last year.

The NBER says its group of academic economists who determine business cycles met and decided that the U.S. recession began in December 2007.

Many economists believe the current downturn will last until the middle of 2009 and will be the most severe slump since the 1981-82 recession.