Can the green merger and acquisition strategy improve the environmental protection investment of listed company?

In recent years, heavy pollution enterprises often adopt green merger and acquisition (GMA) strategy to obtain green technology and resources, so as to realize the transformation and upgrading of pollution industry. Can GMA increase the environmental protection investment (EPI) and promote the green development of enterprises? The important marginal contribution of this paper is to explore the impact of GMA on EPI of heavy pollution listed companies, and compare the impact of different types of GMA on EPI. In this paper, PSM-DID method and nonlinear DID method are used for empirical analysis. The results show that GMA can promote EPI, and the marginal effect of horizontal GMA on EPI is greater than that of vertical GMA and mixed GMA. From the perspective of time effect, GMA has a U-shaped effect of first decreasing and then increasing on EPI. Impact path test shows that GMA inhibits EPI by increasing merger and acquisition cost and management cost, and promotes EPI by improving corporate reputation, environmental awareness, enhancing financing ability and subsidies. Based on the heterogeneity analysis of enterprise life cycle, horizontal GMA has a great impact on EPI in the growth stage. In maturation stage, vertical GMA can promote EPI greatly, but in recession stage, GMA can inhibit EPI.