存在一般性跨收入异质性的非线性税制：充分统计量

中文摘要

本文针对偏好、遗产、收入转移能力及其他来源存在跨收入异质性的情形，为最优非线性税制提供了可进行经验应用的充分统计量公式。我们刻画了针对收入和储蓄（或其他商品）的最优平滑税制，以及更为简化的税制。我们采用常见的弹性概念，并提出一个衡量与收入获取能力相关的异质性的新充分统计量：储蓄的跨收入差异与收入对储蓄的因果效应之差。我们将这些公式应用于美国，发现最优储蓄税大多为正且具有累进性。（JEL E21、G51、H21、H24）

Abstract

This paper provides empirically implementable sufficient statistics formulas for optimal nonlinear tax systems in the presence of across-income heterogeneity in preferences, inheritances, income-shifting capabilities, and other sources. We characterize optimal smooth tax systems on income and savings (or other commodities), as well as simpler tax systems. We use familiar elasticity concepts and a novel sufficient statistic for heterogeneity correlated with earnings ability: the difference between across-income variation in savings and the causal effect of income on savings. We apply these formulas to the United States and find that the optimal savings tax is mostly positive and progressive. (JEL E21, G51, H21, H24)