Recession Officially Started in Dec. '07

However, employment, one of the measurements tracked by the NBER, has been falling since January.

The GDP turned negative again in the July-September quarter of this year, falling at an annual rate of 0.5%. Many economists believe the GDP is falling in the current quarter at an even sharper rate of 4%, and that the economy won't begin to rebound until late 2009.

In a news release, the NBER said its cycle dating committee held a telephone conference call on Friday and made the determination on when the recession began. Founded in 1920, the NBER has more than 1,000 university professors and researchers who act as bureau associates, studying how the economy works

The NBER decision means that the economic expansion lasted from November 2001 until December 2007. Economic expansions peak and recessions begin in the same month, according to the NBER's dating methods.

The decision on the recession means that during the eight years that Bush has been in office, the country has seen two recessions. The first downturn lasted from March 2001 until November of that year.