The federal income tax system in the United States depends upon a high degree of voluntary compliance. The IRS estimates that the voluntary compliance level is declining and that this tax compliance gap cost the government an estimated $90.5 billion in 1981. Between 1979 and 1982, Congress made several changes in the tax laws designed to improve tax compliance. Extensive data was collected by the IRS for 1979 and 1982 through the random sample audits of approximately 50,000 taxpayers on the Taxpayer Compliance Measurement Program (TCMP), which is conducted every three years. During the period 1979 through 1982, Congress lowered the marginal tax rates, added some fairly severe penalties, for both taxpayers and paid return preparers, and increased information reporting requirements for certain types of income. In this research, it was hypothesized that voluntary compliance should increase in response to lower marginal rates, a higher risk of detection due to additional reporting requirements, and increased penalties. Multiple regression analysis was employed to test these hypotheses, using 1979 and 1982 TCMP data. Because of the requirements for taxpayer confidentiality, it was necessary for the IRS to run the data and provide the aggregate data results for the research. The results provided insight into the effectiveness of tax compliance legislation. While the overall voluntary compliance level (VCL) increased from 1979 to 1982 by 1.53 per cent, the VCL increase for taxpayers in high marginal rates was much smaller (.42 percent) than the overall increase. This is very inconsistent with the notion that high marginal rates are driving noncompliance, and suggests that marginal rates may not be strong determinants of compliance. Probably other factors, such as opportunity for evasion, may be more important. There was little change from 1979 to 1982 of the compliance of returns done by paid return preparers. Because of the timing of many TEFRA provisions (effective in 1983), further research for years after 1982 is needed.