Vertical income tax externalities and fiscal interdependence: Evidence from the US Model

Concurrent taxation is a feature of many federal systems. As a result, the tax policy of one level of government affects the tax base of the other. A way to check the empirical relevance of this hypothesis is to test for the existence of interdependencies in the tax setting behaviour of various layers of government. Following this approach, this paper estimates the reaction of U.S. state personal income and general sales taxes to federal tax rates, taking into account the special features of the U.S. tax system. We find that when the federal government increases taxes, there is a significant positive response of state taxes.