Economic effects of a personal capital-income tax add-on to a flat tax

Although much academic and policy discussion has focused on replacing the income tax with a consumption-based tax, very few consumption-based direct tax reforms have been enacted. Much more common are approaches that reduce the level of capital-income taxation under an income tax, including the current Nordic dual income taxes and broadly similar approaches recently proposed in Germany, Switzerland, and the United States. This paper examines the general economic case for such reforms and then reports the results of a simulation of the economic effects of implementing such a capital-income add-on tax to a flat tax structure in the U.S.