In 2009, the Recovery Act boosted monthly benefits for SNAP. The resulting increase in spending on SNAP benefits from 2009 to 2013 was greater than CBO had estimated. This report discusses that underestimate and the reasons for it.
Accuracy of Projections
In its June 2017 projections, CBO overestimated federal outlays and revenues for fiscal year 2018 by 1.7 percent and 1.2 percent, respectively. The projected federal budget deficit for 2018 was 3.7 percent more than the actual amount.
CBO’s March 2016 projections of federal outlays for fiscal year 2017 were $65 billion—or 1.6 percent—more than the actual amount reported by OMB. By comparison, the mean absolute error for projections made for 1993 to 2016 is 2.3 percent.
CBO and JCT project that the federal subsidies, taxes, and penalties associated with health insurance coverage for people under age 65 will result in a net subsidy from the federal government of $685 billion in 2018.
- ReportCBO’s Record of Projecting Subsidies for Health Insurance Under the Affordable Care Act: 2014 to 2016
This report assesses the accuracy of projections that CBO and JCT made in 2010 and 2013 of federal spending for people made newly eligible for Medicaid by the ACA and of subsidies for health insurance purchased through the ACA marketplaces.
In the baseline projections CBO has issued each spring, projected outlays have generally been close to actual amounts, although they have been too high, on average—a consequence of the agency’s economic forecasts and other factors.
CBO's revenue projections since 1982 have, on average, been a bit too high—more so for projections spanning six years than for those spanning two—but their overall accuracy has been similar to that of the projections of other agencies.