最优非线性所得税率结构影响因素：论争焦点及评析

摘要

As both fairness and efficiency are considered , the change in the optimal nonlinear income tax rate is the inter-active result of the two factors .Based on the formula of the optimal marginal tax rate structure , results of numerical simulations and empirical evidence, this article makes a deep analysis on the effect mechanism of social welfare function , skill distribution, utility function and the level of labor supply elasticity on the optimal marginal tax rates .The results indicate that , the previously accepted idea that a higher marginal tax rate will be produced by a highly fair social welfare function , lower labor supply elastic-ity, skills of Pareto distribution and the quasi-linear preference is not fully established .The article concludes that a different opti-mal income tax structure is needed for each country since the optimal income tax theory is built on many simplifying assumptions .%最优所得税必须同时考虑公平与效率，税率结构的变化某种程度上都源自两者的权衡。本文从最优税率结构的求解公式、模拟结果及经验证据，分析了社会福利函数、技能分布、效用函数以及劳动供给弹性等对最优税率的影响。结论认为，学界原来接受的：更平等社会福利函数、更小的劳动供给弹性、技能的帕累托分布和效用的拟线性偏好会产生更高边际税率的观点并不完全成立。同时，由于最优所得税是建立在严格的假设条件基础上的，具体实践中各国需根据自身情况构建最优税制。