The implications of these differences in estimates is illustrated in Table 7-1, which summarizes the various data sources used by BEA in constructing one of its sets of accounts. Gross domestic product (GDP) is mainly estimated using data collected by the Census Bureau, while gross domestic income (GDI) is mainly estimated using data collected by BLS, the Census Bureau, and the Statistics of Income (SOI, part of the Internal Revenue Service, IRS). In concept, GDP should equal GDI because all final expenditures should end up as income to households, business, or government. However, because of the differences in the source data used in estimating GDP and GDI, often they are not equal, and the result is the statistical discrepancy.

Such discrepancies between GDP and GDI can have large impacts on fiscal and monetary policy. During the latter half of the 1990s, a large and persistent discrepancy arose, with real GDI growing 0.6 percent faster than real GDP (1995-2000). This was important for budget planning because real trend GDP growth is used as the baseline for estimating near-term trend growth in 5-year budget forecasts made by the Office of Management and Budget (OMB) and the Congressional Budget Office. To illus-