The Great Recession was a period of general economic decline observed in world markets For background on financial market events dating from , see Financial crisis of According to the U.S. National Bureau of Economic Research (the official arbiter of U.S. recessions) the recession began in December and. The Great Recession began in December and ended in June , which makes it the longest recession since World War II. Beyond its duration, the Great. Business Cycle Expansion and contraction dates for the United States Economy. The determination that the last expansion began in June is the most recent decision of December , Peak, December 1, The NBER does not define a recession in terms of two consecutive quarters of decline in real GDP.