State Income Tax Progressivity

This article compares the degree of personal income tax progressivity in selected states and investigates the determinants of changes in progressivity through time. D. Suits's and N. C. Kakwani's recently proposed summary measures of tax progressivity are estimated and compared for twelve states with comparable income tax systems. Time series estimates are made for a single state, North Carolina. The analysis reveals that there are systematic differences in progressivity among the states and that inflation and real income growth are important determinants of declining state income tax progressivity.