The NBER is the accepted dater of the start and end of recessions in the U.S. When recessions are called by the NBER, they are generally marked by a downward trend in the following variables: real sales in manufacturing and retail, real personal income, payroll employment, and industrial production (NBER 2003). As explained by Novak (2008), the NBER typically makes the call well after the peak of economic activity. The NBER bases this call on the data available at the time of its decision. But these indicators are revised over time. Indeed, these revisions can be substantial, and in some cases, they can significantly change the way we view a period of economic history. This has led to extensive study of data revisions in an attempt to better understand how data are revised (Croushore and Stark, 2000).

As economic growth slows, analysts often want to determine whether the data suggest that the economy is in a recession. They typically compare the current behavior of the monthly statistics the NBER considers with how these statistics behaved around known NBER recession dates. But when looking at current data for past recessions, these analyses use data that incorporate revisions made after the NBER dated the recessions, rather than the data as they looked at the time the NBER made the call. In contrast, the Federal Reserve Bank of Philadelphia’s real-time data set allows us to compare current levels of these variables with their values as they were known at the time past recessions were dated.1 This paper presents this analysis, which allows us to assess whether the current data resemble what the NBER has previously perceived as recessionary.