Analysis Of Environmental Effects Of China's "2+26" Urban Motor Vehicle Restriction Policy Under The Background Of Pollution Prevention And Control

Vehicle restriction policy,as an important measure of urban air pollution control,its effectiveness is the research hotspot of environmental economics.In addition to extensive impact on social welfare,it has important theoretical and practical significance to evaluate the environmental effect of the policy in a scientific way.This paper combs the current situation of China's urban vehicle restriction policy implementation systematically under the background of “China air pollution prevention and control”.On this basis,it analyzes the environmental effects of "2+26" urban vehicle restriction policy in Beijing,Tianjin,Hebei province and its surrounding areas,and identifies the practical and technical factors affecting the scientific evaluation of policy effects.Furthermore,Taking Zhengzhou vehicle restriction policy as the object during the national action of air pollution prevention and control,using the policy evaluation method based on theory,this paper analyzes the background of Zhengzhou vehicle restriction policy comprehensively,and quantitatively analyzes its effect through the quasi-natural experiment estimation method.The results based on different scales show that: the concentration of PM2.5,PM10 and NO2 decreased significantly within 22 days after the implementation of the traffic restriction policy,making the daily air quality index(AQI)increased by at least two grades,and then the effect decreased gradually;the number of monthly heavy pollution days increased by about 9 days in the nine months of policy implementation,and monthly good air quality days decreased by 10-13 days in the first year;the policy effect tended to be stable after 20 months of implementation,and its long-term implementation led to monthly good air quality days decreased by about 2 days,and monthly heavy pollution days increased by about 3 days.Further mechanism analysis shows that the implementation of Zhengzhou vehicle restriction policy is only conducive to the improvement of short-term air quality.The change of residents' long-term travel behavior makes the policy effect on the improvement of air quality little,if there is no other collaborative measures,and even aggravates the air pollution.This paper analyzes the background,purpose,and effect of vehicle restriction policy comprehensively which provides a set of scientific analysis ideas for environmental policy evaluation;the identification of policy effectiveness,timeliness and occurrence mechanism provides the basis for relevant departments to make scientific decisions,which would help to design and guide more targeted strategy system,and further improve the efficiency of urban air pollution governance.