Archive for the 'GDP' Category

Why Does BEA Revise GDP Estimates?

Each summer, the Bureau of Economic Analysis updates its Gross Domestic Product estimates to incorporate sources of data previously unavailable and make improvements in methodology – – all with the goal of providing the most accurate measure of the U.S. economy’s performance.

This year, we’ll release revised estimates for GDP and its major components on July 30. These updated figures will reflect new and revised sources of data and will incorporate the regular updates to seasonal adjustment factors as well as several statistical changes designed to reduce residual seasonality. At the same time, BEA will introduce new tools for analyzing the nation’s economy.

This annual revision process results in old estimates of GDP getting recalculated for both the quarters and years covered – from 2012 through the first quarter of 2015. BEA’s annual revisions usually cover three years. New estimates of GDP will reflect the adopted improvements.

Another improvement that will emerge from this year’s annual revision process is that the BEA – also starting on July 30 — will begin including data from a new “advance” trade report produced by the Census Bureau into our initial estimates of quarterly GDP. The data from Census’ advance trade report will mean that BEA will have actual trade data for all three months of the quarter – rather than only two months — when calculating its first estimate of quarterly GDP.

In addition to the annual revisions process, BEA also regularly updates its quarterly GDP numbers – producing three estimates for a given quarter. Each new estimate includes updated, more complete, and more accurate information as it becomes available. The first, called the “advance” estimate, typically receives the most attention and is released roughly four weeks after the end of a quarter. For example, the first estimate of GDP for this year’s January-to-March quarter came out near the end of April. The first estimate for the second quarter will come out July 30 – in concert with the annual revisions.

When BEA calculates the advance estimate, we don’t yet have complete source data, with the largest gaps in data for the third month of the quarter. In particular, the advance estimate lacks complete source data on inventories, trade, and consumer spending on services. Therefore, we must make assumptions for these missing pieces based in part on past trends. As part of this process, we publish a detailed technical note that lays out the assumptions we made for a particular estimate. With Census’ new advance trade report, BEA will be able to plug the hole on the missing trade data.

As new and more complete data become available, we incorporate that information into the second and third GDP estimates. About 45 percent of the advance estimate is based on initial, or early, estimates from various monthly and quarterly surveys that are subject to revision for various reasons, including late respondents that are eventually incorporated into the survey results. Another roughly 14 percent of the advance estimate is based on historical trends.

By the second GDP estimate, we have new data for the third month and revised data for earlier months. By the third estimate, a lot more data is available so that only 17 percent of the GDP estimate is based on information from the first set of monthly and quarterly surveys.

Once every five years, BEA produces a  “comprehensive” revision to its GDP statistics, incorporating changes to how the U.S. economy is measured as well as more complete source data all the way back to 1929.  The most recent comprehensive revision was 2013.  New data, new methodologies, changes in definitions and classifications, and changes in presentations were all incorporated into 2013’s comprehensive GDP revision.

Measuring GDP for the U.S. economy is always a work in progress. It often takes months, or even years, for the most comprehensive and accurate data to become available. Our advance estimates strike a good balance between accuracy and timeliness, given the data available at the time. Successive revisions reflect BEA’s commitment to incorporate both more complete source data when they become available and improved methods for measuring a rapidly changing economy.

Preview of the 2015 Annual Revision of the National Income and Product Accounts

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On July 30, the Bureau of Economic Analysis will release its annual update of the national income and product accounts (NIPAs) in conjunction with the advance estimate for the second quarter of 2015. As is usual for annual NIPA revisions, the revised estimates will incorporate newly available source data that are more complete, more detailed, and otherwise more reliable than those that were previously incorporated.

This year’s annual revision will introduce the following:

  • An improved treatment of federal refundable tax credits in the personal income and outlays account and the government receipts and expenditures account.
  • Two new aggregates—the average of gross domestic product (GDP) and gross domestic income (GDI) and final sales to private domestic purchasers—that will facilitate the analysis of macroeconomic trends.
  • Improvements to the seasonal adjustment of GDP components, including federal defense spending on services, and of the source data underlying several other NIPA components.
  • An expanded presentation of payments and receipts of transfers and taxes between the United States and the “rest of world” that will harmonize the NIPA presentation of these transactions with the presentation in BEA’s international transactions accounts (ITAs).
  • An improved presentation of exports and imports that provides detail on exports of petroleum and products that will align the NIPA presentation of trade in industrial supplies and materials with the presentation in the ITAs.

Read the entire article in the June Survey of Current Business.