A 1989 DC court decision referred to a 1987 report:
The statutory scheme indicates that Congress sought to promote fairness in the District of Columbia by providing resolution of child support conflicts on an expedited basis through an intermediate tier of hearing commissioners who have ready formulae for calculating support orders. See, e.g., D.C.Code §§ 16-924(a), (f), 30-506(a) (1981, 1988 Repl.). In addition, Congress thought that the uniformity of awards would contribute to their overall fairness and encourage settlements through their predictability.Surprisingly, this 1987 report is not on the web anywhere.
 The recommendations to Congress by the national Advisory Panel on Child Support Guidelines suggest that Congress intended three improvements over the existing method of determining child support: 1) a higher level in support orders, 2) greater fairness through uniformity, and 3) improved efficiency (including expediting cases and encouraging settlements). Development of Guidelines for Child Support Orders: Advisory Panel Recommendations and Final Report II-2 (1987) ("Panel Recommendations"). This interpretation sheds little light on actual Congressional intent, however, since the report was issued after the 1984 Amendments were enacted. In November 1983, the House Ways and Means Committee requested the U.S. Office of Child Support Enforcement to establish this panel and produce a project report. Panel Recommendations at I-3.
A reader has sent me a copy of the report. (pdf, 14M download)
He also sent me Fudging Failure: The Economic Analysis Used to Construct Child Support Guidelines, by Ira Mark Ellman, Report on the Disincentives to the Protection of Marriage, Military Personnel Retention and Recruitment, Resulting from Abuses by the States of the Child Support Performance and Incentive Act (CSPIA), and essay on doing child support plans. I found these on the web.
I am not sure what to make of this stuff yet. I wanted to make the 1987 report publicly available so others can better analyze how we got into the current mess. My hunch is that some ideological consultants bamboozled everyone. Lawmakers debate the tax code, but not child support formulas.