From the Introduction: "When Congress considers legislation, it takes into account the proposal's potential budgetary effects. This helps Members to weigh the legislation's merits, and to consider whether it complies with the budgetary rules that Congress has created for itself. While information on the potential budgetary effects of legislation may come from numerous sources, the authority to determine whether legislation complies with congressional budgetary rules is given to the House and Senate Budget Committees. In this capacity, the budget committees generally rely on estimates provided by the Congressional Budget Office (CBO) and the Joint Committee on Taxation (JCT). [...] Congress has sometimes required that JCT and CBO provide estimates that incorporate such macroeconomic effects. These estimates are often referred to as 'dynamic estimates' or 'dynamic scores.' This report provides information on the authorities and requirements under which cost estimates are prepared, as well as a summary of the debate surrounding dynamic cost estimates, and previous rules and requirements related to dynamic estimates. Currently, no congressional rules explicitly require dynamic estimates, and Congress may examine what rules changes, if any, are needed in the area of dynamic estimates. This report, therefore, includes information on options for the creation of dynamic scoring rules, and general considerations for Congress related to dynamic estimates."
CRS Report for Congress, R46233
Congressional Research Service: https://crsreports.congress.gov/