Income tax in the United States These treaties reduce the chance of double taxation by allowing each country to fully tax its citizens and residents and reducing the amount the other country can tax them. Generally the treaties provide for reduced rates of tax on investment income and limits as to which business income can be taxed. The treaties each define which taxpayers can benefit from the treaty. The United States social insurance system is funded by a tax similar to an income tax. Social Security tax of 6.2% is imposed on wages paid to employees. The tax is imposed on both the employer and the
Legal history of income tax in the United States (1916), the 1913 Act was ruled to be constitutional. A separate excise tax was also imposed on corporations. Subsequent legal actions were concerned with what should be counted as "income" under the 1913 Act. In "Eisner v. Macomber" (1920), the Supreme Court ruled that proportionate stock dividends were not taxable as income, on the grounds that the dividend income was not "severable" from the capital holding from which it was derived. Later decisions, however, have tended to limit this view of "severability," and to uphold the federal statutes as exertions of the power of Congress to tax. The first attempt