A system of taxation in which persons or
corporations are assessed at a greater percentage of their
income according to the theoretical ability to pay. That is,
taxpayers pay more in taxes if they
earn more in
income. For example, taxpayers may pay 25% of their income in taxes up to a certain amount, and 35% of everything earned over that amount.
A theory behind progressive taxation states that persons or corporations who earn the same or a similar amount of
money should be taxed in the same or a similar way. For example, the theory states that two individuals making $50,000 per year should be taxed the same amount, regardless of how they earned their
income. This is known as
horizontal equity. While most countries have some form of progressive taxation, it is usually coupled with other taxes, such as a
sales tax, and few countries treat all income as exactly the same. See also: Regressive tax system.