31 U.S.C. § 1109

(a) On or before the first Monday after January 3 of each year (on or before February 5 in 1986), the President shall submit to both Houses of Congress the estimated budget outlays and proposed budget authority that would be included in the budget for the following fiscal year if programs and activities of the United States Government were carried on during that year at the same level as the current fiscal year without a change in policy. The President shall state the estimated budget outlays and proposed budget authority by function and subfunction under the classifications in the budget summary table under the heading “Budget Authority and Outlays by Function and Agency”, by major programs in each function, and by agency. The President also shall include a statement of the economic and program assumptions on which those budget outlays and budget authority are based, including inflation, real economic growth, and unemployment rates, program caseloads, and pay increases. (b) The Joint Economic Committee shall review the estimated budget outlays and proposed budget authority and submit an economic evaluation of the budget outlays and budget authority to the Committees on the Budget of both Houses before March 1 of each year.