To assess the impact of tax-benefit policy changes on income distribution over time, wesuggest a methodology based on counterfactual simulations. We start by decomposingchanges in inequality/poverty indices into three contributions: reforms of the tax-benefitstructure (rules, rates, etc.),...

The Polish tax and benefit system is presented in the context of a recently developedmicrosimulation model, SIMPL. The model allows simulating direct taxes, social contributionsand public benefits in Poland for the years 2003 and 2005...>br>