等比例税

等比例税是一种固定税率的税，它的税率不会随着征税部分收入的增加或减少而改变，所以税额与征税部分收入成比例。[1]“等比例”描述了这种税对收入或支出的分配效应，特指其税率始终保持一致（随着收入或消费变化不会增高或者降低），边际税率始终不变。[2][3]

參考來源

1. Sommerfeld, Ray M., Silvia A. Madeo, Kenneth E. Anderson, Betty R. Jackson (1992), Concepts of Taxation, Dryden Press: Fort Worth, TX
2. Hyman, David M. (1990) Public Finance: A Contemporary Application of Theory to Policy, 3rd, Dryden Press: Chicago, IL
3. James, Simon (1998) A Dictionary of Taxation, Edgar Elgar Publishing Limited: Northampton, MA