Economic forecasts play an increasing role in U.S. budgetary and fiscal policies. This paper analyzes the accuracy and bias of economic forecasts prepared by the Executive Branch and Congress. Short-run forecasts by the Executive Branch for the forthcoming year do not appear biased. They are as accurate as private forecasts and the forecasts of the Congressional Budget Office (CBO); they are not sensitive to political factors such as the size of the deficit. At the same time, the accuracy of Executive branch's short-run economic forecasts has not improved over the period from 1962 to 1984, and the forecasts themselves can be well approximated by simple, single-equation models that use a small number of variables. In contrast to short-run forecasts, long-run economic forecasts of both the Executive branch and CBO are consistently optimistic. The degree of optimism increases with the length of the forecasting horizon and the degree of fiscal pressure the year in which they are issued. The Reagan Administration's long-run forecasts, while typically optimistic, have not been rosier than those issued under previous administrations.