A tax with a rate that decreases as the taxpayer's income increases.
The result of a regressive tax is that the lower-income taxpayer pays a larger percentage of his or her income in taxes than does the higher-income taxpayer. The opposite of the regressive tax is the progressive tax. With progressive taxes, such as the federal Income Tax, the effective tax rates increase as the taxpayer's income increases. The proportionate tax rate, also referred to as a flat tax rate, remains constant as income rises. Under a proportionate tax system, higher-income individuals pay a greater amount of taxes than lower-income individuals pay, but the ratio is identical.
Consumption taxes, which are taxes on consumer goods and services, are usually regressive because individuals with lower incomes spend a larger portion of their income on these goods and services than higher-income individuals do. Some examples of these consumption taxes are the taxes on alcohol and tobacco, also referred to as "sin taxes."
Some taxes can be a combination of the different tax rates. For example, the Social Security tax is proportional until the taxpayer reaches the maximum income level. However, once the taxpayer's income reaches the maximum cap, all income earned over the cap is not taxed. The result is a regressive tax because the individual earning in excess of the maximum income level is paying a lower percentage of her or his income in taxes than the lower-income individual is paying.