The Suits index of a public policy is a measure of tax progressiveness,[1] named for economist Daniel B.
These effects combine to make income taxes generally progressive, and therefore have a positive Suits index.
Sales taxes are generally charged on each purchase, with no low income exemption.
Excise taxes are typically charged on items like gasoline, alcohol or tobacco products.
Additionally, a poll tax has a Suits index equal to the negative of the Gini coefficient for the same group.