Testing the Predicative Ability of the Tax Progressiveness Indices

The personal income tax is not harmonised in the European Union that’s why there are different systems of the personal income tax which reflects in different nominal tax rates, different allowances, deductions and tax credits. The comparisons based on nominal tax rates predicate the real rate of taxation insufficiently because of these differences. More objective way how to measure the tax circumstances of the taxpayers in individual countries are relative indicators such as the tax incidence of the taxpayer with an average wage, the calculation of an effective tax rate or measuring the tax progressiveness. The index of the tax progressiveness which is based on the effective tax rate predicates the effective tax burden and the relationship between the change of the income and the tax burden. The personal income tax paid by the employee in the period of 1993–2008 in the Czech Republic was chosen for analysis. The paper deals with the application of tax progressiveness indices on the tax system of the Czech Republic. Calculations are performed of the effective tax rate, the progressiveness of the average rate, the progressiveness of the tax obligation and the progressiveness of earning after taxation for an employee who claims only the basic allowances (from 1993–2005), or the tax credit (from 2006–2008) and does not claim any other tax reliefs or credits. It is tested how sensitively the particular indices of the tax progressiveness react to the changes of the effective tax rate.