Synergies of green policies and their pollution reduction effects: Quantitative analysis of China's green policy texts

Synergy is an important step to enhance policy effectiveness and has been discussed in many fields. In order to promote the transformation and upgrading of polluting industries, green policy synergy is urgent to be studied comprehensively. Thus, this paper analyzes the temporal evolution laws of policy content synergy, policy department synergy, and policy type synergy, and further investigates the pollution reduction effect of policy synergy according to the green policy texts issued by Chinese ministries and commissions from 2001 to 2021. The results are as follows. (1) Policy content synergy significantly suppresses the emission intensity of various pollutants. The pollution reduction effect is proportional to the content synergy degree of policies. (2) The policy department synergy significantly reduces the emission intensity of sulfur dioxide, solid waste, and comprehensive pollution, but the suppression effect on chemical oxygen demand and ammonia nitrogen oxygen demand is not obvious. (3) The pollution reduction effect varies with the policy type synergy. Specifically, the synergistic pollution reduction effect of command and control, market incentive, and public participation policies is the best, followed by market incentive and public participation policies, and that of command and control and market incentive policies is the worst. (4) Further research shows that energy consumption significantly negatively regulates the pollution reduction of the policy content synergy and the policy type synergy, but not the policy department synergy. Meanwhile, adjusting industrial structure can promote pollution reduction. This study provides an important reference for enhancing the synergy among green policies and achieving the goal of carbon peak and carbon neutrality.