The panel that decides US business cycles today declared the US economy pulled out of its recession after eight months in November 2001 and is now in recovery.
The announcement from the National Bureau of Economic Research confirmed what many economists already believed - that the economy has resumed growing, albeit slowly.
Members of the panel, widely accepted as the arbiter of US business cycles, had said determining when the recession ended had been complicated by the surprising gains in the productivity of US businesses, which had enabled firms to boost output while laying off workers.
They recently decided to give more weight to measures of US gross domestic product in their deliberations, a decision NBER President Mr Martin Feldstein said would likely make it easier to conclude when the recession ended.
US GDP has been growing slowly since late 2001, and the panel noted it was now 3.3 per cent above its pre-recession peak in the fourth quarter of 2000.
The committee said the length of the downturn, which started in March 2001, was "slightly less than average" for recessions in the post World War Two period.