The Case for a Progressive Tax: From Basic Research to Policy Recommendation
基于最优税收理论的最新成果，论证了累进税制的合理性，提出对高收入者征高边际税率、对低收入家庭提供劳动补贴并逐步退出、对资本收入征税三项政策建议，并批判了零边际税率和零资本所得税率等经典结论的政策相关性。
This paper presents the case for tax progressivity based on recent results in optimal tax theory. We consider the optimal progressivity of earnings taxation and whether capital income should be taxed. We critically discuss the academic research on these topics and when and how the results can be used for policy recommendations. We argue that a result from basic research is relevant for policy only if 1) it is based on economic mechanisms that are empirically relevant and first order to the problem, 2) it is reasonably robust to changes in the modeling assumptions, and 3) the policy prescription is implementable (i.e, is socially acceptable and not too complex). We obtain three policy recommendations from basic research that satisfy these criteria reasonably well. First, very high earners should be subject to high and rising marginal tax rates on earnings. Second, low-income families should be encouraged to work with earnings subsidies, which should then be phased-out with high implicit marginal tax rates. Third, capital income should be taxed. We explain why the famous zero marginal tax rate result for the top earner in the Mirrlees model and the zero capital income tax rate results of Chamley and Judd, and Atkinson and Stiglitz are not policy relevant in our view.