Research On The Pollution Reduction Effect Of The National Water Ecological Civilization City Pilot Polic

Over the past 40 years of reform and opening up,China has made remarkable achievements in economic growth,but at the same time,there has been an increasingly serious problem of water pollution.Water pollution not only seriously affects the health of residents,but also hinders the sustainable development of economy and society.However,water environment belongs to typical public goods,which inevitably brings negative externalities such as “opportunism” and “free riding”.In addition,as a public property,water environmental resources are prone to the phenomenon of “tragedy of the commons” because its property right is difficult to define,resulting in a sharp decline in the quantity and quality of water environmental resources.Therefore,to solve the externality of public goods in water environment,the government needs to adopt corresponding environmental regulation policies to realize the internalization of externality.As early as 2005,the Chinese government put forward the idea that “green water and green mountains are golden mountains and silver mountains”.Subsequently,in the context of the construction of ecological civilization,from 2012 to 2014,the Ministry of Water Resources launched the pilot construction of national water ecological civilization cities in 105 cities,which is of great practical significance for promoting high-quality urban development,promoting the construction of ecological civilization and realizing the vision of a beautiful China.Taking the national water ecological civilization city pilot policy as the starting point,this paper systematically investigates the following four aspects: whether the implementation of the national water ecological civilization city pilot policy has achieved the expected effect of promoting urban pollution reduction;the transmission mechanism of the impact of the national water ecological civilization city pilot policy on pollution reduction;heterogeneity analysis of the impact of national water ecological civilization city pilot policy on pollution reduction;the spatial spillover effect of the national water ecological civilization city pilot policy on pollution reduction.Firstly,using the panel data of 272 prefecture level and above cities in China from 2004 to 2019,this paper investigates the impact of the national water ecological civilization city pilot policy on pollution reduction based on the multi-stage differencein-differences(DID)model.The results show that the national water ecological civilization city pilot policy has a significant effect on pollution reduction,that is,the implementation of this policy can significantly reduce urban water pollution emissions.This conclusion is reinforced by a series of robustness test results based on parallel trend test,PSM-DID test,placebo test,excluding other policy interference,excluding special samples,combined fixed effect and so on.Further,considering that the goal of the national water ecological civilization city pilot policy is not only to improve the urban water ecological environment,but also to improve water use efficiency,save water resources and promote the improvement of environmental total factor productivity,this paper also constructs a multi-stage DID model to investigate the impact of the national water ecological civilization pilot policy on urban water use efficiency and environmental total factor productivity.The results show that the national water ecological civilization city pilot policy significantly improves the urban water use efficiency,but inhibits the improvement of environmental total factor productivity.Then,this paper matches the weekly observation data of water quality monitoring stations in major national watersheds from 2004 to 2018 with the data of national water ecological civilization construction pilot cities,and constructs a multistage DID model to identify the impact of national water ecological civilization city pilot policies on pollution reduction from the micro water quality level.The results show that the implementation of the national pilot policy of water ecological civilized city has significantly improved the water environment quality characterized by chemical oxygen demand and ammonia nitrogen.The robustness test results based on parallel trend test,interference elimination policy,replacement of explained variables,PSM-DID and other methods and strategies show that this conclusion is reliable.Secondly,in order to verify the three transmission mechanisms of the national water ecological civilization city pilot policy affecting pollution emission reduction,this paper uses the panel data at the city level to construct an intermediary effect model to test the technological innovation effect,environmental governance investment effect and public environmental concern effect of the national water ecological civilization city pilot policy.Based on the availability of data,this paper uses per capita patent applications to measure technological innovation,and takes it as an intermediary variable to empirically test the transmission channel of the national water ecological civilization city pilot policy affecting pollution emission reduction.The results show that the national water ecological civilization city pilot policy can improve environmental quality by promoting technological innovation,which also means that the effect of technological innovation is an important channel for the national water ecological civilization city pilot policy to affect pollution reduction.Further,this paper uses the proportion of wastewater treatment investment in GDP to measure the investment in environmental treatment,and takes it as an intermediary variable to empirically test the transmission channel of the national water ecological civilization city pilot policy affecting pollution emission reduction.The results show that the national water ecological civilization city pilot policy can indeed improve environmental quality by increasing environmental governance investment,which shows that the investment effect of environmental governance is an important channel for the national water ecological civilization city pilot policy to affect pollution reduction.In addition,this paper uses the baidu municipal annual search volume of the keywords “water pollution”,“water environment”,“water ecology”,“water ecological civilization” and “national water ecological civilized city” divided by the total population of the corresponding city to reflect the public environmental concern at the urban level,taking it as an intermediary variable,this paper makes an empirical test on the transmission channel of the national water ecological civilization city pilot policy affecting pollution emission reduction.The results show that the national water ecological civilization city pilot policy can indeed improve the urban environmental quality by improving the public environmental concern,that is,the public environmental concern is an important channel for the national water ecological civilization city pilot policy to affect urban pollution reduction.Thirdly,considering the difference of urban characteristics,it may affect the pollution reduction effect of the national water ecological civilization city pilot policy.Based on the data of 272 prefecture level and above cities in China from 2004 to 2019 and the weekly observation data of water pollution in key sections of major national watersheds from 2004 to 2018,this paper adopts multi-stage DDD model and multistage did model to cut in from five aspects: economic development difference,population density difference,administrative grade difference,human capital difference and water resource endowment,investigates whether the pollution emission reduction effect of the national water ecological civilization city pilot policy has a different impact on cities with different characteristics.The results show that in terms of differences in economic development,the national water ecological civilization city pilot policy has economic development heterogeneity on pollution emission,that is,the pollution emission reduction effect of the national water ecological civilization city pilot policy is more obvious in cities with higher economic development level.In terms of population density difference,the national water ecological civilization city pilot policy has population density heterogeneity on pollution emission,that is,the pollution emission reduction effect of the national water ecological civilization city pilot policy is more obvious in cities with low population density.In terms of administrative level differences,the national water ecological civilization city pilot policy has administrative level heterogeneity on pollution emission,that is,in cities with lower administrative level,the pollution emission reduction effect of the national water ecological civilization city pilot policy is more significant.In terms of human capital differences,the national water ecological civilization city pilot policy has human capital heterogeneity on pollution emission,that is,in cities with high human capital,the pollution emission reduction effect of the national water ecological civilization city pilot policy is more obvious.In terms of differences in water resources endowment,the national pilot policy of water ecological civilized cities has heterogeneity in Water Resources Endowment for pollution discharge,that is,the pollution emission reduction effect of the national pilot policy of water ecological civilized cities is more obvious in cities with low water resources endowment.Finally,considering that the proximity of urban spatial location may lead to the impact of the national water ecological civilization city pilot policy on the pollution emission reduction of surrounding cities,this paper empirically investigates the spatial spillover effect of the national water ecological civilization city pilot policy on pollution emission reduction by taking 272 prefecture level and above cities from 2004 to 2019 as research samples.In order to test the spatial autocorrelation,this paper uses the inverse distance matrix and the square matrix of the inverse distance matrix as the spatial weight matrix to calculate the global Moran index of sewage discharge intensity,and draws the scatter diagram of the local Moran index.The results show that the sewage discharge intensity among cities is not randomly distributed in space,but there is spatial agglomeration,and shows a positive spatial correlation to a certain extent,which means that cities with high(low)sewage discharge intensity tend to be adjacent to cities with high(low)sewage discharge intensity.Further,based on the spatial Durbin model,this paper empirically tests the spatial spillover effect of the national water ecological civilization city pilot policy on pollution reduction.The results show that the national water ecological civilization pilot cities and the surrounding cities that have also implemented the national water ecological civilization city pilot policy do not show a synergistic treatment effect,but play a role in reducing the pollution emission of the city at the same time.In addition,based on the regression results of spatial weight matrix,this paper obtains the direct effect,indirect effect and total effect of core explanatory variables.The results show that whether the inverse distance matrix or the square of the inverse distance matrix is used as the spatial weight matrix to investigate the spatial spillover effect of the national water ecological civilized city pilot policy on pollution emission reduction,consistent results are obtained,that is,the positive effect of the implementation of the national water ecological civilized city pilot policy on urban pollution emission reduction is limited to the interior of the city implementing the policy.However,there is no obvious spatial spillover effect between cities,and the positive impact on the pollution emission reduction of adjacent cities in the pilot cities of the policy is not obvious.In addition,this paper sets up multiple local spatial weight matrices to investigate the impact of the national water ecological civilized city pilot policy on pollution reduction in different distances.The results show that within the distance of 100-200 kilometers,the implementation of the national water ecological civilization city pilot policy can significantly reduce the city’s pollution emissions,however,if the surrounding cities also implement the national water ecological civilization city pilot policy,there will be a positive spatial spillover effect,which will lead to a significant increase in pollution emissions in the city.The research conclusions of this paper provide important policy enlightenment for promoting the construction of ecological civilization,promoting environmental governance and realizing the vision of a beautiful China: first,continue to promote the construction of national water ecological civilized cities;second,realize the coordinated development of pollution reduction and economic growth;third,strengthen technological innovation,investment in environmental governance and public attention to the environment;fourth,form a national water ecological civilization city construction model with its own characteristics;fifth,build a coordinated pollution control mechanism among cities.