Individual Income Tax Rates and Other Key Elements of the Individual Income Tax: 1988 To 2013 [February 1, 2013] [open pdf - 391KB]
"Statutory individual income tax rates are the tax rates that apply by law to various amounts of taxable income. Statutory rates lay the foundation for marginal and average effective tax rates, which most economists believe have a greater impact on the economic behavior of companies and individuals than statutory rates. Marginal effective rates reflect the net effect of special tax provisions on statutory rates. They are to be distinguished from average effective rates, which measure someone's tax burden. Current statutory and effective individual tax rates are the result of the Tax Reform Act of 1986 (TRA86; P.L. 99-514) and several tax laws that have been enacted since 1986. […] This report summarizes the tax brackets and other key elements of the individual income tax that help determine taxpayers' marginal and average effective tax rates going back to 1988. It is updated annually to reflect the most recent indexation adjustments and any statutory changes."
CRS Report for Congress, RL34498