Some Further Results on Income Tax Progression

Recently there have been some publications on the progression of the tax system, especially of the income tax. Kakwani (1977) proposed a "new measure of tax progressivity" that - following Kakwani - expresses the severity of progression for the entire income area in a single number. This measure is based on the Gini index and comes close to the "effective progression" of Musgrave and Thin (1948). Both measures show theoretical and statistical shortcomings, especially they do not tell us anything about the serverity of the progression, as far as the individual tax payer is concerned. This can be satisfied particularly by the measures proposed by Musgrave and Thin (1948), the liability progression and the residual income progression. A simulation model' for the German income tax system has been used to give some empirical evidence