There are a large number of published studies describing the effects of CCCP policies. From an economic perspective, the consequences of CCCP are unfavorable. Shi et al. (2018) pointed out that full compliance with CCCP would lead to a significant gap between supply and demand, resulting in a substantial increase in coal prices and economic costs. The effects of different policy instruments of the CCCP are significantly different on the macroeconomic system, but regardless of which policy tool is used, the CCCP will inevitably lead to a reduction in social welfare(Zhang et al., 2021). In contrast, (Li and Yao, 2020) demonstrated that CCCP contributed to energy conservation and carbon emission reduction, but only with a slight loss of economic efficiency. Chen and Chen (2019) focused on "2+26 cities" and predicted the environmental effect of CCCP in the building sector. The results showed that the policy could cause an increase in natural gas and electricity consumption, which could help reduce SO2 and NOx emissions, and it is helpful for some less developed areas to achieve the goal of low carbon faster. Ji et al. (2018) used Jiangsu province as a case study for the effect of CCCP. They found that a stricter target for CCCP would promote energy structure adjustment, curb pollution, and protect traditional energy resources. Compared with the analysis of the CCCP effect from an aggregate perspective, emission intensity and energy intensity in China have more research value because they are binding indicators for local government evaluation. However, there is a relatively small body of literature that focuses on energy intensity. Shi et al. (2018) take the Jing-Jin-Ji region as Study Subject and pointed out that coal-to-power and coal-to-gas policies have an insignificant negative effect on energy intensity. Guo et al. (2020) expanded the scope of the study to 272 cities across the country, but they found that the CCCP introduced in 2011 had unexpectedly increased China's energy intensity, and only with the help of supportive policies, it can have a negative effect on energy intensity.
Air-pollutant emissions are relevant to economic development, industrial structure (Wang et al., 2019), technological innovation (Wang et al., 2019), population (Brajer et al., 2011), foreign direct investment (Copeland and Taylor, 1994; Jiang et al., 2014; Taylor and Copeland, 1997), energy structure (Xia et al., 2021). Greenhouse gas emissions are related to economic growth (Kivyiro and Arminen, 2014; Omri et al., 2014), foreign direct investment(Omri et al., 2014; Ren et al., 2014), energy structure (Akalpler and Shingil, 2017), industrial structure (Tian et al., 2014; Zhang and Deng, 2010), population (Dietz and Rosa, 1997), technological innovation (Chen and Lee, 2020), industrial structure (Wang et al., 2014).
A constant decline in energy intensity shows that a country's economic activities are moving toward a more ecological and sustainable mode(Ma and Yu, 2017). While a number of studies have examined the determinations of energy intensity and accepted that R&D (Huang and Chen, 2020; Lin and Wang, 2014; Tan and Lin, 2018; Zheng et al., 2011), and GDP per capita (Wang and Han, 2017) are the most crucial factor in improving energy intensity. With the progress of economic globalization, research has shown that technology spillovers from foreign direct investment also affect energy intensity. However, it is controversial whether FDI contributes to reducing energy intensity (Bu et al., 2019; Mielnik and Goldemberg, 2002). Wu and Ding (2021) found that secondary industries consume more energy than other industries, as industrialization continues, energy intensity also increases (Chen & Lee, 2020). Moreover, the impact of population on energy intensity is ambiguous: as an energy consumer, a large population would increase total energy consumption (Fu et al., 2015), but as a labour force, it would significantly increase GDP.
China's emissions mainly come from energy consumption in the production process. Three main emission reduction measures are typically taken by enterprises (Zhou et al., 2019), such as industrial restructuring, technological innovation, and optimizing the energy structure. Under the constraint of the CCCP, the industry is likely to prioritize dismantling backward capacity and replacing backward industries with high energy consumption and high environmental impact. Regarding technological innovation, to achieve stable and low energy consumption and sustainable development, enterprises increase research funds by strengthening internal technology (Ullah et al. 2021). On the other hand, they will also upgrade technology by introducing external resources, such as importing advanced energy-saving and environmental protection technologies, to achieve qualitative changes in energy use efficiency and reduce emission intensity. The energy substitution effect of switching the energy structure from coal-based to diversified energy sources also affects energy and emission intensity. Thus previous standard literature noted that CCCP reduced the energy intensity of emissions via industrial restructuring, technological innovation, optimizing the energy structure.
Model And Method
Following Zhang et al. (2018) and literature, we assume the coal consumption control policy is a key determinant of energy efficiency and pollution emissions. Thus, we begin with the following energy efficiency and pollution emissions models:
$$\text{l}\text{n}\left(gso{2}_{it}\right)={\beta }_{0}+{\beta }_{1}Dit+{\theta }_{1}\text{l}\text{n}(pgdp{)}_{it}+{\theta }_{2}{industry}_{it}+{\theta }_{4}{\text{l}\text{n}\left(pop\right)}_{it}+{\theta }_{5}ln({\text{t}\text{e}\text{c})}_{it}{+{\theta }_{6}{\text{l}\text{n}\left(fdi\right)}_{it}+{\theta }_{7}{coal}_{\_\_}c+{\mu }_{i}+{\gamma }_{t}+\epsilon }_{it}$$
1
$$\text{l}\text{n}\left(gco{2}_{it}\right)={\beta \text{'}}_{0}+{\beta \text{'}}_{1}Dit\text{'}+{\theta \text{'}}_{1}\text{l}\text{n}(pgdp{)}_{it}+{\theta \text{'}}_{2}{industry}_{it}+{\theta \text{'}}_{4}{\text{l}\text{n}\left(pop\right)}_{it}+{\theta \text{'}}_{5}ln({\text{t}\text{e}\text{c})}_{it}{+{\theta \text{'}}_{6}{\text{l}\text{n}\left(fdi\right)}_{it}+{\theta \text{'}}_{7}{coal}_{\_\_}c+{\mu \text{'}}_{i}+{\gamma \text{'}}_{t}+\epsilon \text{'}}_{it}$$
2
$${\text{toconsum}}_{-}{c}_{it}={\beta }_{0}^{{\prime }{\prime }}+{\beta \text{'}\text{'}}_{1}Dit\text{'}\text{'}+{\theta \text{'}\text{'}}_{1}\text{l}\text{n}(pgdp{)}_{it}+{\theta }_{2}^{{\prime }{\prime }}\text{industr}{y}_{it}+{\theta }_{4}^{{\prime }{\prime }}{\text{l}\text{n}\left(\text{p}\text{o}\text{p}\right)}_{it}+{\theta }_{5}^{{\prime }{\prime }}ln({\text{t}\text{e}\text{c})}_{it}+{\theta \text{'}\text{'}}_{6}{\text{l}\text{n}\left(fdi\right)}_{it}+{\theta \text{'}\text{'}}_{7}{coal}_{\_\_}c+{\mu }_{i}^{{\prime }{\prime }}+{\gamma \text{'}}_{t}^{{\prime }}+{\epsilon \text{'}}_{it}^{{\prime }}$$
3
Dit=treatedi*periodt
Where i and t denote cities and years, respectively; gso2 is a measure of so2 emission intensity; gco2 represents co2 emission intensity; and toconsum_c denotes energy intensity that depends on pgdp (GDP per capita), industry (secondary industry output value), FDI (foreign direct investment), coal_c (coal consumption in total energy consumption), pop (population), and tec (technological progress). The variable of interest is \({\text{D}}_{it}\), \({\text{D}}_{it}{\prime },{\text{D}}_{it}{\prime }{\prime }\), dummies that take the value of 1 in the years after city i implementing CCCP and 0 otherwise. The coefficients \({\beta }_{1}, {\beta \text{'}}_{1}, {\beta \text{'}}_{1}\), are the parameters to be estimated, representing the net effect of CCCP. A positive and significant one indicates the CCCP exerts a positive effect on the intensity of SO2 emission and CO2 emission, energy intensity, while a negative and significant one suggests that CCCP pushed intensity of SO2 emission and CO2 emission lower. While, \({{\mu }}_{\text{i}}, {{\mu }{\prime }}_{\text{i}}, {{\mu }{\prime }{\prime }}_{\text{i}}\) and \({{\gamma }}_{\text{t}}, {{\gamma }{\prime }}_{\text{t}}, {{{\gamma }{\prime }}^{{\prime }}}_{\text{t}}\) are vectors of city and year dummy variables that account for city and year fixed effects, but \({{\epsilon }}_{\text{i}\text{t}}, {{\epsilon }{\prime }}_{\text{i}\text{t}}, { {\epsilon }{\prime }{\prime }}_{\text{i}\text{t}}\) are the random disturbance terms.
To further understand the specific implementation path of the policy, we employ the intermediate model to test which path-among adjusting the industrial structure, promoting technological progress, and reducing energy intensity- is most effective in reducing CO2 and SO2 emissions and energy intensity. The traditional multiple mediation model, a regression analysis based on the causality test proposed by Baron and Kenny (1986), is less efficient in estimating mediation effects(Fritz and MacKinnon, 2007). The Sobel test used in regression analysis assumes that a*b obeys a normal distribution, whereas mediation effects often do not meet the required, resulting in test results being relatively unreliable(Bollen and Stine, 1990; Stone and Sobel, 1990). SEM can address the shortcomings of the above methods. It is the best framework for mediated effects analysis because it can estimate all model parameters simultaneously and efficiently (Zhao et al., 2010). Therefore, this study explores the specific pathways through which CCCP works by building SEM models.
Data
This study examines the impact of CCCP on CO2 emissions, air pollution, and energy intensity by covering 73 cities of China over the period from 2005 to 2019. Table A1 reported the list of cities in the appendix. Therefore, CO2 emission, energy structure, and energy intensity coal consumption data were obtained based on our unique database. Specifically, we collected all data on 24 energy types published in the urban statistical yearbooks. Then, cities with missing for consecutive years were removed and the number of cities was finally set to 73. The raw energy data are uniformly converted to standard coal and summed up so that we get the total energy consumption. Additionally, as for coal consumption, it is calculated using 12 coal energies of the industry which is uniformly converted to standard coal and summed up. The rest of the data come from the China city statistical yearbooks. The variables description and descriptive statistics of the variables are shown in Table 1.
Table 1
Symbol
|
Variable
|
Unit
|
Mean
|
S.D
|
gso2
|
Sulphur dioxide emissions from industrial sector per unit of output value
|
Tones /CNY
|
0.00429
|
0.00664
|
gco2
|
Carbon dioxide emissions from industrial sector per unit of output value
|
Tones /CNY
|
0.00047
|
0.00068
|
toconsum_g
|
Ratio of Energy consumption to output value
|
N/A
|
1.12860
|
1.55894
|
pgdp
|
GDP per capita
|
CNY/people
|
73465.8
|
66010.7
|
industry
|
The proportion of secondary industry in total output value
|
%
|
47.9730
|
9.36703
|
pop
|
Total population at the end of the year
|
Million
|
440.943
|
440.943
|
tec
|
the proportion of Scientific expenditure in Local fiscal expenditure
|
N/A
|
0.02265
|
0.01823
|
fdi
|
the proportion of Actual amount of foreign capital used in the year of GDP
|
million USD/ ten thousand CNY
|
0.00427
|
0.00347
|
Coal_c
|
the proportion of coal consumption in total energy consumption
|
N/A
|
0.66348
|
0.24356
|
2Raw Coal, Finely washed coal, Other washed coal, Briquette, Other coal products (pulverized coal, coal water slurry), Coke, Crude Oil, Fuel oil, Gasoline, Diesel oil, General kerosene, Refinery thousand gas, Liquefied Natural Gas, Liquefied Petroleum Gas, Naphtha, Other petroleum products, Natural Gas, Blast Furnace Gas, Converter Gas, Coke Oven Gas, Other Gas, Heat, Electricity.
3Raw coal, washed coal, other washed coal, coal products, coke, other coking products, coke oven gas, blast furnace gas, converter gas, producer gas, other coal gas
4Available website of China City Statistical yearbook: http://data.cnki.net