Abstract: Labor income share is an important indicator of labor welfare and Macroeconomic development. The labor income share in China has a U-shaped pattern; it declined between 1995 and 2008,then began to increase. This is the inverse of the GDP growth pattern. Therefore, it is important to investigate the underlying determinants of labor income share. At present, most of the researches focus on the four factors that affect labor income share:the biased technological progress and incomplete competition, the change of economic structure and the change of negotiation ability of production factors caused by globalization. In the context of a new round of global industrial revolution, the research on the impact of fixed asset investment on labor income share is of great significance for China's economic and social development. However, the research on this issue is relatively scarce in China. In 2014, China began to implement the fixed assets acceleration policy for pilot industries. This tax incentive policy can reduce the tax burden of enterprises and increase the scale of fixed asset investment. In this paper, we use the accelerated depreciation policy of fixed assets in 2014 as exogenous shock and the micro data of China's A-share listed companies from 2007 to 2019 to identify the causal relationship between fixed asset investment and labor income share. The study finds that the policy significantly raises the labor income share of listed companies. Further analysis shows that the policy significantly increases the labor income share of private enterprises, but has no significant effect on state-owned enterprises; the policy significantly increases the labor income share of firms in the eastern region, but has no significant effect on firms in the western region; the policy significantly increases the labor income share of ordinary employees, but has no significant effect on the labor income share of senior managers; the policy significantly reduces the capital income share, but increases the labor income share of income of subjects other than capital and labor. In addition, consistent with the theoretical analysis, the labor creation effect brought by fixed asset investment is greater than the labor substitution effect, and the superimposed comprehensive effect significantly improves the labor income of enterprises, and then increases the share of labor income. To sum up, this paper verifies the relationship between fixed asset investment and labor income share from the micro perspective, and extends the research on the effect of tax incentive policy to the level of labor income share of enterprises, so as to provide reference for further reform in the future.

Key words: labor income share, tax incentive, accelerated depreciation of the fixed assets, difference-in-differences model