Box: Examples of Source Data and Methods Used To Prepare the Economic Accounts

Example estimate from the NIPA's: Personal consumption expenditures on goods

Personal consumption expenditures (PCE) makes up about two-thirds of GDP, and durable and nondurable goods account for over two-fifths of that (services account for the remainder). The table below shows the methodology for the advance quarterly and annual current-dollar estimates for goods (with estimates for 1993).

In the context of the discussion of sources and methods, there are several points of interest:

Diverse source data: Among the source data are the Census Bureau's sequence of a monthly survey, an annual survey, and a census for retail trade; the Bureau of Labor Statistics Consumer Price Indexes; data from several trade sources; administrative data from several Federal agencies; and data from BEA's balance of payments accounts.

Sequence of revisions: The "most goods" category undergoes a sequence of revisions as the source data become more complete. Census Bureau retail sales data are available for all 3 months of the quarter at the time of the advance quarterly estimate; data for the third month are preliminary and subject to revision. The retail sales data are further revised with the release of the annual survey, and these are incorporated into the PCE estimates in the second annual revision. The data are further revised with the release of the economic census, and these are incorporated into the PCE estimates in the NIPA comprehensive revision.

Role of estimating methods: The retail control method mentioned in the "most goods" description provides both an indicator series used in interpolating and extrapolating and a total to which the categories in the group must sum. This method makes it possible to use retail sales by type of business to obtain type-of-goods detail (assuming that the types of goods purchased at various kinds of stores do not change rapidly).