Progressive Taxation and Income Inequality: The Intermediate View of Inequality

It is known that the post-tax income is more equally distributed than pre-tax income according to any μ-invariant inequality index satisfying Dalton's principle of transfers, if, and only if, a tax function is progressive for μ-inequality (Pfingsten [8]). This paper provides a rigorous formulation of the equivalence, both in strong and weak form. We show that any non-equally distributed pre-tax income distribution is dominated by the resulting post-tax income distribution in the sense of the μ - Lorenz criterion if, and only if, a tax function satisfies both (a)incentive preserving taxation and (b)progressive taxation for μ-inequality