Abstract: Reducing the stickiness of corporate income tax burden is conducive to strengthening the sense of access to the policies for corporate tax and fees and releasing the cumulative effect of tax and fee reduction policies. Using the data of the listed enterprises from 2008 to 2020, this paper constructs a year-by-year PMS model and a multi-period DID model to empirically analyze the impact of“tax on social security”on the stickiness of corporate income tax burden. The results show that labor cost stickiness plays a mediating role between“tax on social security”and the stickiness of corporate income tax burden, and that the implementation of“tax on social security”has enhanced the stickiness of corporate income tax burden. The tax burden of corporate income tax is more viscous for service enterprises, small-scale enterprises and enterprises with lower social security contributions; and the tax burden of corporate income tax is more viscous for enterprises with lower regional financial self-sufficiency, lower wage level and lower participation rate of social security. Therefore, it is necessary to formulate differentiated tax policies, use modern technology to strengthen social security collection and management; to oblige enterprises to sign employment contracts with their employees, so as to regulate labor practices; to weaken the motivation of enterprise for surplus management, and strengthen the awareness of enterprise tax cost management; to improve the relevant supporting policies, such as giving certain supporting policies to financially difficult regions and enterprises in difficulties, moderately increasing tax credits for social security contributions, etc.

Key words: tax on social security, corporate income tax, tax burden stickiness, social security collection and management, labor cost