The expected federal budget surplus: how much confidence should the public and policymakers place in the projections?

When the government runs a deficit, it can borrow from the public—that is, it can create debt. Conversely, when the government runs a surplus, it can retire that debt. For the past three years, the federal government has recorded budget surpluses, and both the White House Office of Management and Budget and the Congressional Budget Office project that these surpluses will increase for at least the next decade. If these projections prove to be accurate, the $3.5 trillion of publicly held federal debt could be eliminated by around 2010. This article, which was written prior to the updated estimates published in January 2001, assesses the likelihood that these projected surpluses will materialize, and consequently eliminate the public debt, by comparing previous budget projections with actual outcomes. The authors show that the long-term budget projections have not provided a useful indicator of actual experience. Principally, these errors occur because of changes in macroeconomic conditions or unforeseen legislative actions, which both result in unanticipated increases or decreases in revenues or outlays. Not surprisingly, the projections have proven to be less reliable the longer the projection horizon. Moreover, over the period of available data, the projections have been biased upward, i.e., the actual deficits have been larger than projected. Accordingly, the authors suggest that prospects for eliminating the public debt may be overstated.