How does a re-basing change the GDP calculation

US GDP per year versus recessions and events

Nominal GDP is total US economic output for that year. The BEA also calls it "current dollar GDP" because it is measured as the dollar amount and does not take into account factors such as inflation. Experts use nominal GDP to compare economic performance with US debt, which is also measured in dollars without taking inflation into account. The article "National debt by year" shows the debt ratio since 1929.

Real GDP accounts for inflationThis makes comparisons with previous years more accurate. The BEA uses it to calculate the GDP growth rate and GDP per capita. Real GDP is important because without canceling the effects of inflation, if only prices really go up, GDP could appear to be growing.

The current base year for GDP calculations is 2012. The period from which the weights for a series of measurements are derived. The National Income and Product Accounts (NIPAs) currently use the year 2000 as the base period. Re-basing changes the reference year (or base year) for the real value (chained dollar and quantity index). Estimates and price indices and expresses GDP and other NIPA aggregates in the form of prices from one year. The rebasing creates chained dollar estimates that are closer to the additive for periods near the new base year. It is important to note that percentage changes based on chain indexes are not affected by rebasing.

In general, the year selected as the reference year is the last year and will not be revised until the next major update. For the 2018 comprehensive update, the real estimates were changed from chained (2005) dollars to chained (2012) dollars.

While GDP is a closely watched economic indicator, finding more economic data can give GDP numbers wider context. Here is a list of indicators and historical events closely related to the US economy: