Not that there was much doubt about it, but the Business Cycle Dating Committee of the National Bureau of Economic Research, the official arbiter when it comes to recessions, has declared that the nation's economic contraction began a year ago - in December 2007. That marked the end of an expansion lasting 73 months; the previous expansion of the 1990s lasted 120 months. Recessions have been loosely defined as two consecutive quarters of negative growth, but this little-known organization ultimately has the last word. (It’s worth noting that the GDP didn’t get into negative territory until the third quarter of this year.) Recessions over the last half century have lasted an average of 10 months, but the one in the mid-70s dragged on for 17. That still suggests an upturn in the second half of 2009, though that’s barely more than a guess. (Real Time Economics)