Joumard, Pisu and Bloch (2012) state that the redistributive impact of taxes and transfers depends on their size, mix and the progressivity of each component, and found that taxes and cash transfers reduced income inequality, as measured by the Gini index, by about 25% on average in oecd member countries towards 2010. In those countries, direct transfers reduce income dispersion more than taxes: three quarters of the reduction in inequality between market income and disposable income are due to transfers, the rest to taxes. Moreover, countries with a more unequal distribution of market income tend to redistribute more. A second objective is to simulate the possible effects of potential reforms of tax systems, in order to demonstrate that tax instruments —and in particular that putting the resulting increase in revenue to good use— can have a significant impact on the distribution of disposable income.