Individual Income Taxation Since 1948

Still the largest and most important source of government revenues in the United States, the individual income tax has been altered significantly over time by legislation, inflation, the maturation of retirement systems, and other factors. This article provides an historical analysis of many aspects of this tax over the postwar era: revenues collected, the size of the tax base and the role of exclusions, deductions, exemptions and credits in defining that base, tax-exempt levels of income, and the overall progressivity of the rate structure. Many postwar trends are found to halt or reverse themselves in the 1980s.