Abstract:     The government policy is a key element in promoting green innovation in enterprises. Exploring the policy effects of the government in improving the efficiency of green innovation in enterprises is an important issue of common concern for policy makers and enterprises. This paper incorporated incentive and disincentive policies into the unified research framework of corporate green innovation efficiency, and analyzed the overall and heterogeneous impact mechanisms of R&D subsidies, tax incentives and environmental regulation policy tools on the green innovation efficiency of enterprises. Constructing the multidimensional fixed effect model to collect relevant data on incentive, inhibition policies and green innovation of listed companies in the A-share heavily polluting industries of Shanghai and Shenzhen from 2010 to 2021, measuring and comparing the effect size of different policy tools on corporate green innovation efficiency, it was found: (1) On the whole, the effect of incentive policy is greater than that of inhibition policy. The combination policy is the largest incentive policy, followed by research and development subsidies. (2) From the perspective of life cycle, the growth stage is dominated by the effect of incentive policies and supplemented by the inhibition policies; in the incentive policy, the combination policy is larger, followed by research and development subsidies; in the mature stage, the effect of restraining policy is the main one, and the incentive policy is the auxiliary one. The research and development subsidy has the greatest effect among the incentive policies. In the recession period, the effect of incentive policy is the main one, and the effect of inhibition policy is the auxiliary one. (3) From the nature of property rights, state-owned enterprises, mainly to inhibit the effect of policies, incentive policies as a supplement; Among the incentive policies, tax preference has the greatest effect. For non-state-owned enterprises, the incentive policy is the main effect, and the inhibition policy is the auxiliary; The combination policy is the largest incentive policy, followed by research and development subsidies. This paper has explored the impact of different policy tools on corporate green innovation, which has important practical implications for the government to implement precise policies to promote corporate pollution reduction and efficiency improvement.

Key words:  incentive policy, repression policy, enterprise green innovation efficiency, life cycle, property right nature