MEASUREMENT OF TAX PROGRESSION WITH DIFFERENT INCOME DISTRIBUTIONS

This paper reviews methods of comparing income tax progression. Section II deals with local measures of tax progression, Section III with global measures of tax progression, and Section IV with uniform tax progression. It is shown that all of this measures have specific drawbacks: they either ignore the income distribution altogether, aggregate over income intervals with pro-gression and regression, or they require that the same income distribution holds for comparisons of different tax schedules. However, realistic comparisons of tax progression ask for comparisons of different tax schedules associated with different income distributions. This is addressed in Section V for uniform tax progression with different income distributions. A respective condition of higher progression turns out as the sum of elasticities of the tax schedule and the density function of the income distribution. Alas, this is only a sufficient, not a necessary condition. The paper concluded with the challenge to find necessary and sufficient conditions for uniform tax progression with different income distributions. JEL Classification: H23