累进税(progressive tax)
指税率随应课税的数额递增而递增所徵收的税。其目的在於向富人徵收较多的税，其观点是有钱人应当承担更多的税务负担。累进所得税可保证一定数额下的工资免税，或根据收入的提高而建立起越来越高的收入税。扣除额的存在也可产生一个税的累进。累进税在通货膨胀或经济衰退时期都是一项稳定力量，因为税收额的变化按比例要大於人们收入增减的变化。例如，在通货膨胀的经济中，尽管物价上涨和收入增加，但纳税人的收入大部分要用来缴税。但这一系统的副作用是低收入的纳税人在通货膨胀很高的时期内可能难以维持生计。为了弥补这一缺憾，许多经济学家提倡采用指数化，许多国家每年在通货膨胀期调整税收率，通常同消费者物价指数保持一致。亦请参阅regressive tax。
English version：
progressive tax
Tax levied at a rate that increases as the quantity subject to taxation increases. Designed to collect a greater proportion of tax revenue from wealthy people, progressive taxes reflect the view that those who are able to pay more should carry a heavier share of the tax burden. Progressive income taxes may provide for exemption from tax liability for incomes under a specified amount, or may establish progressively greater rates for larger and larger incomes. The presence of deductions can also make a tax progressive. Progressive taxes are a stabilizing force in periods of inflation or recession because the amount of tax revenue changes more than proportionately with an increase or decrease in income. For example, in an inflationary economy, as prices and incomes rise, a greater percentage of taxpayers' income goes toward taxes. Government revenues increase, and the government has more leverage over the economy. A side effect of this system is that lower-income taxpayers have an especially difficult time making ends meet when inflation is high. To compensate, many economists advocate indexation; several countries adjust their tax rates annually in times of inflation, usually in line with the consumer price index. See also regressive tax.