Minimum wage system is the legal guarantee for workers to obtain labor remuneration, and exploring the impact of accelerating robot application is an important proposition. The impact of minimum wage on labor income share has attracted much attention, but with the increasing application of robots in recent years, it has not been widely and deeply discussed, especially the internal mechanism from the level of micro firms.

This paper constructs a comprehensive theoretical framework model of minimum wage and robot application affecting labor income share, and combs the impact mechanism of minimum wage on labor income share and the moderating effect of robot application on the impact of minimum wage from the two aspects of wage rate and labor productivity. Using the data of listed companies from 2012 to 2019, manually collecting the minimum wage data of prefecture-level cities, and combining the data of the International Federation of Robots (IFR), this paper empirically tests how robot application affects the compensation effect of minimum wage on labor income share by building tool variables, replacing core explanatory variables and explained variables, and conducting a series of heterogeneity analysis. The findings are that: (1) The increase of minimum wage significantly increases labor income share, and robot application weakens the promoting effect of minimum wage on labor income share. The compensation effect of minimum wage on labor income share will decrease with the continuous increase of robot penetration. (2) Heterogeneity analysis shows that robot application significantly reduces the compensation effect of minimum wage on labor income share in large-scale firms, low-wage firms and capital-intensive industries. In small and medium-sized cities and large cities, robot application inhibits the compensation effect of minimum wage on labor income share, while in mega-cities, robot application strengthens this compensation effect. (3) The increase of minimum wage significantly increases the wage rate, which verifies that the wage rate is the channel through which the minimum wage affects labor income share. Robot application promotes the demand of highly-educated staff to replace the demand of low-educated staff, which is a supplement and verification of the influence channel of wage rate. This paper provides new ideas and references for China’s labor protection policy and robot industry development policy.

The marginal contributions of this paper are as follows: First, it explores the impact of minimum wage on labor income share from robot application, which enriches the existing research on income distribution and labor income share. Second, it constructs a model for the effect of robot application on the minimum wage, which verifies how robot application affects the compensation effect of minimum wage on labor income share, and provides direct evidence of the effect of robot application from the micro level. Third, it verifies that wage rate is the channel through which robot application reduces the compensation effect of minimum wage on labor income share, which provides implications for understanding the evolution of labor income share.