Within the research area “Tax Policy and Redistribution” we analyse the efficiency, distributional and welfare effects of tax policy, both from a national and an international perspective. We conduct ex-post analyses of past reforms using administrative microdata. In addition, we investigate reform proposals in ex-ante analyses utilising experimental methods and behavioural microsimulation models. Based on our empirical results, we develop policy recommendations to design tax and transfer systems. Researchers in the area have close ties to the Leibniz ScienceCampus MannheimTaxation.