Flat tax? Maybe not a bad idea after all

This work studies the actual degree of progressivity in the Italian tax and transfer system and examines possible reforms towards the optimum. It analyzes the distribution of personal income and effective tax rates across the Italian population, computing income and tax liabilities from survey data, and studies the optimal level of progressivity. To this end, it uses a model developed in Heathcote et al. (2017) with heterogeneous agents where skill investment and labor supply are endogenous and the government provides a public good under a balanced budget. All the main tradeoffs that shape optimal progressivity appear: the presence of inequality in initial conditions and imperfect private insurance push for positive progressivity, whereas labor supply and skill investment call for regressivity. The model suggests a drastic reduction in progressivity under both the baseline and the alternative specifications. In particular, it calls for substantial reductions in marginal tax rates above approximately 0.25 times the mean income along with increased tax rates at the lower end of the income distribution. These reforms may be approximated by a flat tax at 29% under the baseline and at 32.5% under the alternative specification, holding the required positive level of progressivity constant.