The National Bureau of Economic Research said Monday that the U.S. economy has been in a recession since December 2007. And we are being told this now, a full year later? Tell us something we didn't know.

The NBER said its group of academic economists who determine business cycles met and decided that the U.S. recession began last December. Many economists now believe that the current downturn will last through the middle of 2009, and will mark the most severe slump since the 1981-82 recession.

Some consider a recession to occur whenever the gross domestic product (GDP) declines for two consecutive quarters. But the NBER uses broader and more precise measurements.

The GDP contracted by .2 percent in the fourth quarter of 2007, but was followed by a .9 percent increase in the first quarter and a 2.8 percent jump in the second quarter when the economy was boosted by economic stimulus payments. It turned negative again in the July-Sept. quarter of this year, falling .5 percent, and many economists believe the GDP is falling in the current quarter at a rate of 4 percent.

One of the measurements that the NBER tracks, employment, has been falling since January.

The NBER, a nonprofit private research organization, said its cycle dating committee held a telephone conference call Friday and made the determination on when the recession began. The NBER was founded in 1920, and currently has more than 1,000 university professors and researchers that act as bureau associates and study how the economy works.

What the NBER's decision means is that the economic expansion spaned November 2001 to December 2007. According to NBER's dating methods, economic expansions peak and recessions begin in the same month.

This means that during George W. Bush's eight years in office, the country has seen two recessions, the first which was in March 2001 and lasted until November 2001.