The comprehensive update of the NIPAs marks the culmination of an estimating cycle that typically takes 5 years. The cycle begins with three "current" estimates for each quarter. The quarterly estimates are subject to annual updates, usually released at the end of each July, that typically incorporate data for at least the 5 most recent years. A comprehensive, or benchmark update, is timed to incorporate the benchmark input-output (I-O) accounts, which provide levels of the components of GDP for the benchmark year.
A comprehensive update also incorporates three major types of improvements:
- Changes in definitions and classifications that update the accounts to reflect the changing U.S. economy. Efforts are also made to improve international comparability by conforming more closely to the accounting framework of the System of National Accounts.
- Statistical changes that update the accounts to reflect the introduction of new and improved methodologies and the incorporation of newly available and revised source data, such as the benchmark I-O accounts.
- Presentational changes that update the NIPA tables to reflect the definitional and statistical changes and make the tables more informative.