3.2. Analysis of the Second-Stage Stochastic Frontier Regression Results
To eliminate the influence of the external environment and random noise on agricultural land productivity, the slack values of input factors in the first stage are taken as the dependent variables, and the environmental factors in
Table 1 are taken as the independent variables. The Frontier4.1 software is used for data analysis. A positive regression coefficient indicates that there is input redundancy that is not conducive to improving environmental governance efficiency. Conversely, a negative coefficient value is beneficial for improving environmental governance efficiency. The specific regression results are shown in
Table 4.
According to
Table 4, most of the environmental variables are significantly related to the input slack variables at a significance level of 1%, indicating a close correlation between external environmental factors and the efficiency of environmental governance in China.
For redundant investment in the treatment of industrial waste, the level of industrialization, per capita GDP, and population density negatively and significantly affect the redundant investment in the treatment of industrial waste, which is conducive to improving environmental governance efficiency. However, the level of urbanization, fiscal revenue scale, degree of openness, economic growth rate, and government size have a positive and significant impact on redundant investment in the treatment of industrial waste, which is not conducive to improving environmental governance efficiency.
For redundant total power in agricultural machinery, the level of industrialization, population density, government size, and the number of industrial enterprises negatively and significantly affect the redundant total power in agricultural machinery, which is conducive to improving environmental governance efficiency. However, the scale of fiscal revenue and economic growth rate have a positive and significant impact on the redundant total power in agricultural machinery, which is not conducive to improving environmental governance efficiency.
For redundant employees in water, environmental, and public facility management, the level of urbanization and industrialization negatively and significantly affect the redundant employees in water, environmental, and public facility management, which is conducive to improving environmental governance efficiency. However, population density, degree of openness, economic growth rate, government size, and the number of industrial enterprises have a positive and significant impact on redundant employees in water, environmental, and public facility management, which is not conducive to improving environmental governance efficiency.
For redundant investment in the living environment, the level of urbanization, industrialization, per capita GDP, and the number of industrial enterprises negatively and significantly affect the redundant investment in the living environment, which is conducive to improving environmental governance efficiency. However, population density, fiscal revenue scale, degree of openness, economic growth rate, and government size have a positive and significant impact on redundant investment in living environment, which is not conducive to improving environmental governance efficiency.
For redundant investment in the ecological environment, per capita GDP, government size, and the number of industrial enterprises negatively and significantly affect redundant investment in the ecological environment, which is conducive to improving environmental governance efficiency. However, the level of urbanization, industrialization, population density, fiscal revenue scale, degree of openness, and economic growth rate have a positive and significant impact on redundant investment in the ecological environment, which is not conducive to improving environmental governance efficiency.
It can be seen that for the two input variable redundancies in the production environment, the factors that have a positive impact are mostly economic factors, indicating that the more economically developed the region is, the more likely it is to have input variable redundancy, and it also indicates that the more economically developed the region is, the larger the scope and difficulty of environmental governance will be, and it will be more likely to have a “high input, low output” characterization. At the same time, economic development and environmental governance usually have an inverted “U” relationship, indicating that China is still in the upward phase of the EKC curve, that is, the stage of sacrificing the environment for economic development, and has not yet reached the turning point of the EKC curve. For the input variable redundancy in the living environment and ecological environment, in addition to economic factors, population factors will also have a positive impact, indicating that the efficiency of governance in the living environment and ecological environment will be affected by both economic factors and population factors. Overall, external environmental factors have different impacts on various input redundancies. Based on this comprehensive analysis, due to the different external environments in different regions, the factors affecting the efficiency of environmental governance and their directions and magnitudes of influence are inevitably different. These differences will lead to deviations in environmental governance efficiency. Therefore, it is necessary to eliminate the influence of environmental variables and recalculate efficiency.
3.4. Evaluation of Environmental Governance Efficiency Based on the Cloud Model
To explore the spatial differentiation trend of China’s environmental governance efficiency, this paper combines the mean deviation method with the cloud model, and uses the adjusted environmental governance efficiency as the basis to divide 27 provinces into five levels, from low to high: low environmental governance efficiency, relatively low environmental governance efficiency, general environmental governance efficiency, relatively high environmental governance efficiency, and high environmental governance efficiency. In order to more accurately measure the environmental governance efficiency of each province, considering that each province and region faces different environmental problems and economic conditions, it is obviously unreliable to simply apply an evaluation system to evaluate all provinces. Setting up an evaluation system for each region to evaluate environmental governance efficiency is more scientific and objective. Therefore, evaluation systems are generated for the eastern, central, western, and national regions to evaluate the provinces in different regions, and the national evaluation system evaluates the overall environmental governance efficiency of the three regions.
According to the cloud model principle, the environmental governance efficiency evaluation index system is taken as the theoretical domain, each research object is taken as a cloud drop, and the overall characteristics of the cloud formed according to the integrated results of all research objects’ evaluation of all indicators reflect the environmental governance efficiency, according to which the process of the environmental governance efficiency evaluation method is designed as follows:
Due to the difference in the measurement scale of the research index system, it is not necessary to normalize the environmental governance efficiency data.
First, according to the mean deviation method, the five evaluation level ranges are confirmed, and then according to the bilateral constraint criterion, the value of each rubric is taken within the limited family domain, and the minimum value of the rubric is set
and the maximum value is
. The three numerical characteristics of the evaluation criteria cloud are calculated as follows.
In Equation (7), denotes randomness, and in this paper, is taken as 0.01.
Calculations are performed according to the equations of the inverse cloud model above, as detailed in Equations (5) and (6), to derive the cloud parameters for each province.
The numerical characteristics of the cloud models corresponding to the evaluation levels are specified in
Table 7. The parameters of the cloud model scores for each province and region are detailed in
Table 8.
Based on the above data, we organize our main observations into four categories:
(1) Evaluation of the environmental governance efficiencies of provinces in the eastern region. Based on the comparison of cloud parameters of provinces in the eastern region with the evaluation of the cloud parameters of the eastern region, it can be observed that Beijing, Tianjin, and Hainan belong to provinces with high environmental governance efficiencies; Fujian belongs to a province and city with general environmental governance efficiencies; and Hainan has achieved effective environmental governance. Hebei belongs to a province with relatively low environmental governance efficiency and Shanghai, Jiangsu, Zhejiang, Shandong, and Guangdong belong to provinces with low environmental governance efficiencies. Therefore, the environmental governance efficiencies of the vast majority of provinces in the eastern region are not high. Moreover, through entropy analysis, it can be observed that although Beijing, Tianjin, and Hainan have high environmental governance efficiencies, their entropy values are also ranked in the top three, indicating that there is a large span of environmental governance efficiencies in these three provinces from 2003 to 2020, and although their governance efficiencies are high, their overall states are unstable. The entropy values of the other provinces are generally low, indicating that the environmental governance efficiencies of the other provinces are generally stable. Among them, the super-entropy values of Zhejiang, Fujian, and Guangdong are greater than 0, indicating that the cloud model curves of Zhejiang, Fujian, and Guangdong have a certain degree of fuzziness, which means that the development of environmental governance efficiencies in these three provinces from 2003 to 2020 are not balanced, and there may be uneven development among factors that affect environmental governance efficiency or they may be affected by government public value preferences or policies. The super-entropy values of the other provinces are all 0, indicating that the development of environmental governance efficiencies in the other provinces is generally stable. Overall, taking into account the allocation of expected values, entropy, and super-entropy, it can be concluded that the environmental governance efficiency of Fujian best represents the overall situation in the eastern region.
(2) Evaluation of the environmental governance efficiencies of provinces in the central region. After comparing the cloud parameters of provinces in the central region with the evaluation of the cloud parameters of the central region, it was found that Jiangxi belongs to the province with high environmental governance efficiency, Shanxi belongs to the province with relatively high environmental governance efficiency, Hubei belongs to the province with average environmental governance efficiency, Hunan belongs to the province with relatively low environmental governance efficiency, and Anhui and Henan belong to the provinces with low environmental governance efficiencies. It can be seen that the environmental governance efficiencies in the central region show a normal distribution overall, and the overall distribution is relatively balanced. Through the entropy value, it can be observed that although Jiangxi has the highest environmental governance efficiency in the central region, the span of its environmental governance efficiency is also the largest, indicating that its environmental governance efficiency is in a certain state of instability. The entropy values of the other provinces are basically consistent, indicating that the changes in the environmental governance efficiencies of the other provinces are more stable. From the super-entropy value, it can be observed that the super entropies of Anhui, Jiangxi, and Hunan are all greater than 0, indicating that there are differences between the factors that affect their environmental governance efficiencies, or that there are other factors that may have an impact, resulting in more unstable and hazy states of their environmental governance efficiencies. Overall, considering the values of expectation, entropy, and super entropy, it can be concluded that the environmental governance efficiency of Hubei best represents the overall situation in the central region.
(3) Evaluation of the environmental governance efficiencies of provinces in western China. After comparing the cloud parameters of each province and city in western China with the evaluation of the cloud parameters of western China, it was found that Inner Mongolia, Guizhou, Gansu, and Qinghai belong to provinces with high environmental governance efficiencies, and all four provinces have achieved effective environmental governance. Yunnan belongs to provinces with relatively high environmental governance efficiencies, Shaanxi and Ningxia belong to provinces with average environmental governance efficiencies, and Guangxi, Chongqing, Sichuan, and Xinjiang belong to provinces with low environmental governance efficiencies. Therefore, the environmental governance efficiency in western China generally exhibits a distribution characteristic of a normal distribution, and the overall distribution is relatively balanced. Through entropy analysis, we can see that the entropy values of Chongqing, Sichuan, Guizhou, Yunnan, Shaanxi, Ningxia, and Qinghai are all high, indicating that the environmental governance efficiencies of these seven provinces exhibit a certain degree of instability and fluctuate greatly from 2003 to 2020. On the other hand, the environmental governance efficiency fluctuations of Inner Mongolia, Guangxi, Gansu, and Xinjiang are smaller and tend to be stable. From the perspective of super entropy, the super-entropy values of Inner Mongolia, Guangxi, Chongqing, Sichuan, and Guizhou are all greater than 0, indicating that there are differences between the factors affecting their environmental governance efficiencies, or that there are other factors affecting these efficiencies, leading to more unstable and fuzzy states. Overall, considering the values of expectation, entropy, and super entropy, it can be concluded that the environmental governance efficiency of Yunnan best represents the overall situation in western China.
(4) Evaluation of the environmental governance efficiencies of provinces from a national perspective. After comparing the cloud parameters of 27 provinces in the western region with the evaluation of the cloud parameters of the national scope, it was found that Hainan, Inner Mongolia, Guizhou, Yunnan, Shaanxi, Gansu, Ningxia, and Qinghai are provinces with high environmental governance efficiency. Beijing belongs to the province with a relatively high environmental governance efficiency, while Tianjin, Jiangxi, Chongqing, and Sichuan belong to provinces with average environmental governance efficiencies. Hebei, Shanghai, Jiangsu, Zhejiang, Fujian, Shandong, Guangdong, Shanxi, Anhui, Henan, Hubei, Hunan, Guangxi, and Xinjiang are all provinces with low environmental governance efficiencies. From a national perspective, the environmental governance efficiencies of the 27 provinces show a “big difference between high and low, with the middle being small” and “low efficiency in the eastern and central regions, with instability in the western region”. There are large differences in the environmental governance efficiencies among provinces, and there is still much room for improvement and upgrading overall. Considering the allocation of expected value, entropy, and super entropy, it can be concluded that the environmental governance efficiencies of Jiangxi and Chongqing best represent the overall situation of environmental governance efficiency in the national scope.