Progressivité de l'impôt fédéral direct et de la TVA en Suisse

The author develops global indexes of the progressivity and the redistributive effects of taxes and transfers, based on Lorenz curves and Gini indexes. He simulates the introduction in Switzerland of a regressive VAT with a 15% tax rate, in the context of the existing progressive federal income tax. The global tax system becomes proportional to income, whereas it was still progressive with the actual VAT rate of 6.5%. The article presents the properties of a flat-rate tax and concludes that only a negative income tax, or more generally a transfer to the lower incomes, can compensate the regressivity of a 15% VAT and preserve the progressivity of the federal tax system.