In situations where a portion of a period is included in the recession, the whole period is deemed to be included in the recession period.
The first interpretation, known as the midpoint method, is to show a recession from the midpoint of the peak through the midpoint of the trough for monthly and quarterly data.
As another example, the Committee did not declare a recession for 2001 or 2003, even though the data at the time appeared to show a decline in economic activity (though not for two quarters).
The recession shading data that we provide initially comes from the source as a list of dates that are either an economic peak or trough.
We interpret dates into recession shading data using one of three arbitrary methods.
First, we do not identify economic activity solely with real GDP, but use a range of indicators, notably employment.
Second, we consider the depth of the decline in economic activity.
For this time series, the recession begins the first day of the period following a peak and ends on the last day of the period of the trough.