A progressive tax is a tax in which the tax rate increases as the taxable base amount increases."Progressive" describes a distribution effect on income or expenditure, referring to the way the rate progresses from low to high, where the average tax rate is less than the marginal tax rate. It can be applied to individual taxes or to a tax system as a whole; a year, multi-year, or lifetime. Progressive taxes attempt to reduce the tax incidence of people with a lower ability-to-pay, as they shift the incidence increasingly to those with a higher ability-to-pay. The opposite of a progressive tax is a regressive tax, where the relative tax rate or burden increases as an individual's ability to pay it decreases.
The term is frequently applied in reference to personal income taxes, where people with more income pay a higher percentage of that income in tax than do those with less income. It can also apply to adjustment of the tax base by using tax exemptions, tax credits, or selective taxation that creates progressive distribution effects. For example, a sales tax on luxury goods or the exemption of basic necessities may be described as having progressive effects as it increases a tax burden on high end consumption or decreases a tax burden on low end consumption respectively.
Progressive taxation often must be considered as part of an overall system since tax codes have many interdependent variables. For example, when refundable tax credits and other tax incentives are included across the entire income spectrum, the United States has the most progressive income tax code among its peer nations; although its overall income tax rates are below the OECD average.