Data are revised for a variety of reasons. Perhaps the most familiar sources of revisions are the three releases of the National Income and Product Accounts each quarter. Refinements to seasonal adjustment factors and implicit price deflators are other sources of data revisions. Recently, the Federal Reserve Bank of Philadelphia constructed a realtime data set that gives the data as they were reported at the time, for each quarter since 1967. For instance, there are around 120 vintages of data for the year 1970— one for each quarter since then.
Suggested citation: "Real-Time Data," Federal Reserve Bank of Cleveland, Economic Trends, no. 00-12, pp. 04-05, 12.01.2000.