OPTIMAL CONTROL OF EXTERNALITIES IN THE PRESENCE OF INCOME TAXATION*
研究了在劳动所得税已造成扭曲的情况下，皮古税规则（边际税收等于边际外部损害）是否需要修改。发现简单的一阶最优规则（商品税等于边际损害）仍能实现帕累托改进，并解释了与以往研究的差异。
A substantial literature examines how the Pigouvian directive that marginal taxes should equal marginal external harms needs to be modified in light of the preexisting distortion due to labor income taxation. Additional literature considers distributive concerns. It is demonstrated, however, that simple first‐best rules—unmodified for labor supply distortion or distribution—are correct in the model examined. Specifically, setting all commodity taxes equal to marginal harms (and subsidies equal to marginal benefits) can generate a Pareto improvement, as can a marginal reform toward the first‐best. Qualifications and explanations for differences from previous work are also presented.