Impact of environmental regulation policy on environmental regulation level: a quasi-natural experiment based on carbon emission trading pilot.

This study calculates the green investment level of each province in China and objectively estimates the provincial environmental regulation level from the perspective of the government to examine the effectiveness and impact of the government's environmental protection policy on the environmental regulation level. The carbon emission trading pilot policy is determined through a quasi-natural experiment difference in difference model to examine the impact and assess the effectiveness of green environmental protection policies on the environmental regulation level empirically. Results show that (i) the green investment level of the carbon emission trading pilot provinces is significantly lower than that of other nonpilot provinces after 2013, and (ii) the introduction of environmental protection policies has reduced the government's green investment level by approximately 8%. These findings confirm that environmental regulation policies play a significant role in promoting the environmental regulation level. Further mechanism analysis shows that environmental regulation policies influence this level through carbon dioxide emissions. This study provides a reference for environmental regulation policy making.