To assess the impact of tax-bene?t policy changes on income distribution over time, we suggest a methodology based on counterfactual simulations. We start by decomposing changes in inequal- ity/poverty indices into three contributions: reforms of the tax-bene?t structure (rules, rates, etc.),...

Using counterfactual microsimulations, Shapley decompositions of time change in inequality and poverty indices make it possible to disentangle and quantify the relative effect of tax-benefit policy changes, compared to all other effects including shifts in the distribution of market income....