of investment income. In 2023, the state introduced a surtax of 4% on higher income, thus ending its flat tax system. During its existence, this flat tax was in addition to the progressive rates imposed by the federal government of the United States. introduced a flat tax on interest and dividends in 1929, at a rate of 5%. The rate was changed to 6% in 1937, 5% in 2016, 4% in 2017, 3% in 2018, 2% in 2019, 1% in 2020, and the tax was repealed in 2021. This flat tax was in addition to the progressive rates imposed by the federal government of the United States. See also Consumption tax Excess burden of taxation (or more broadly deadweight loss) FairTax Fiscal drag (also known as Bracket creep) Georgism Income tax Kemp Commission Land value tax Negative income tax Optimal tax Progressive tax Regressive tax Sales tax Single tax Taxable income elasticity (also known as Laffer Curve) Value added tax 9–9–9 Plan Notes References Steve Forbes, 2005. Flat Tax Revolution. Washington: Regnery Publishing. Robert Hall and Alvin Rabushka, 1995 (1985). The Flat Tax. Hoover Institution Press. Richard Parncutt, 2006–2010. Free enterprise without poverty: Effectively progressive income tax.. Anthony J. Evans, "Ideas and Interests: The Flat Tax" Open Republic 1(1), 2005 External links The Laffer Curve: Past, Present and Future: A detailed examination of the theory behind the Laffer curve, and many case studies of tax cuts on government revenue in the United States Podcast of Rabushka discussing the flat tax: Alvin Rabushka discusses the flat tax with Russ Roberts on EconTalk. Podcast of Rabushka discussing the flat tax: Alvin Rabushka discusses the flat tax on PoliTalk. The Flat Tax: How it Works and Why it is Good for America Taxation and redistribution