提高劳动报酬在初次分配中的比重，以及完善直接税制度并逐步提高其比重是当前中国的重大政策需求。如何通过税制改革以提高劳动收入份额是重要但仍然存在争议的研究问题。企业所得税是对资本要素征税，通过影响要素相对价格这一市场机制，进而影响微观企业和宏观劳动收入份额。本项目从企业所得税改革视角解释中国劳动收入份额先下降后上升的变化趋势。基于中国企业所得税改革制度背景和劳动收入份额变化特征事实，本项目的研究包括三个方面：（1）从微观和宏观两个维度系统地构建企业所得税影响劳动收入份额的理论机制，微观机制包括要素投入比例、技术进步偏向和资本结构效应，宏观机制包括行业内部和行业结构效应；（2）利用微观企业数据和企业所得税改革外生政策冲击，评估企业所得税税率变化对企业劳动收入份额的因果影响，并利用宏观省级数据检验行业内部和行业结构效应；（3）研究如何通过税制改革以达到既减税降费又提高劳动收入份额的政策需求。

It’s the major policy need for current China to increase the share of labor remuneration in the primary distribution and improve the direct tax system with its proportion being gradually increased. How to raise the labor share of income through the tax reform is an important but still controversial research question. Corporate income tax is a tax on capital factors, and it affects the labor share of income at the firm-level and macro-level by influencing the market mechanism of relative prices of factors. This project interprets the down and up trend of the labor share of income in China from the perspectives of corporate income tax reforms. Based on the institutional background of China’s corporate income tax reforms and the stylized facts of the changes in the labor share of income in China, the study of this project includes the following three aspects. Firstly, this project systematically constructs a theoretical mechanism for the effect of corporate income tax on the labor share of income in micro- and macro-dimensions. The micro-mechanisms include the input ratio of factors effect, the bias of the technological progress effect and the capital structure effect, while the macro-mechanisms include the intra-industry effect and the industry structure effect. Secondly, using the firm-level data and the exogenous policy shocks of the corporate income tax reforms, this project evaluates the causal effects of the changes in the corporate income tax rate on the firm-level labor share of income. Using the provincial level data, this project examines the intra-industry effect and the industry structure effect. Lastly, this project studies the way of tax reform to meet the policy need of both cutting taxes and administrative fees and raising the labor share of income.