Business cycle dating committee national bureau
A definition of a recession commonly used in the media is two consecutive quarters of a shrinking gross domestic product (GDP).
In contrast, the NBER defines a recession as "a significant decline in economic activity spread across the economy, lasting more than a few months, normally visible in real GDP, real income, employment, industrial production, and wholesale-retail sales." Business cycle dates are determined by the NBER dating committee under contract with the Department of Commerce.
The NBER is well known for its start and end dates of US recessions.
However, the NBER release had noted that "In determining that a trough occurred in June 2009, the committee did not conclude that economic conditions since that month have been favorable or that the economy has returned to operating at normal capacity.
Second, since the NBER wishes to measure the duration of economic expansion and recession at a fine grain, they place emphasis on monthly—rather than quarterly—economic indicators.
Finally, by using a looser definition, they can take into account the depth of decline in economic activity.
Specifically, the Committee identifies a month when the economy reached a peak of activity and a later month when the economy reached a trough.
Recessions start at the peak of a business cycle and end at the trough, ie, a period when economic activity is contracting, and an expansion is the period between a trough and a peak when the economy is expanding.