# Granger Causality Analysis of Foreign Trade in Cement Products and Ecological Impact in China

Authors: Chen Feng
Journal: Mathematical Problems in Engineering
 (2022)

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## Abstract

This paper presents an in-depth study and analysis of the impact of foreign trade on cement products and the ecological environment in China through Granger causality analysis. Based on the theoretical basis of foreign trade, ecological environment, and the relationship between them, a general equilibrium model is used to empirically analyze the “three effects” of foreign trade in Chinese cement products on the ecological environment, and the effects of import and export trade on ecological environment and the net effects are calculated, respectively. Then, based on the data of domestic and foreign cement product production and trade, the purpose, scope, and environmental impact factors of the ecological impact of foreign trade of Chinese cement products were determined by the life cycle assessment method, and the inventory analysis was carried out in phases based on the six aspects of nonrenewable resource depletion, global warming, photochemical ozone generation, acidification, eutrophication, and human health damage. The results were characterized and standardized, and the hierarchical analysis method was used to weight the evaluation of each environmental impact type, and finally, the resource consumption coefficient and environmental impact load index values and corresponding ratios were determined based on the green product evaluation method. This paper establishes an index system for the ecological and environmental impacts of foreign trade of cement products, which is a guide for the ecological and environmental impacts of foreign trade of other products in China. The results of the study on the ecological and environmental impacts of foreign trade of Chinese cement products also have important practical significance for the formulation of regulations and standards related to the cement industry, the adjustment of the import and export structure of cement products, and the improvement of production equipment and processes.


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## Body

## 1. Introduction

Amid economic globalization and fierce market competition, human material civilization has developed rapidly, yet this has also increased the pressure on the healthy development of resources and the environment. While the wave of the industrial revolution pushes the development of productivity, it also brings different degrees of environmental pollution problems. While pursuing material life civilization, human beings must pay attention to the traditional industrial model as a kind of over-consumption and predatory development, which makes the quality of resources and environment deteriorate continuously [1]. Humankind began to reflect on whether the path of economic development was not accompanied by the deteriorating quality of the environment. People realize that it is unscientific to pursue economic growth unilaterally without considering resources and the environment, so how to promote the coordinated development of economic growth and energy conservation and environmental protection has become an issue of keen concern [2]. At present, China’s economic growth has entered a new normal stage, with the growth rate shifting from high to medium-high, but this does not mean that China is no longer concerned about the speed of economic growth, but rather focuses on the quality of development. China is now in the ranks of middle-income countries, but this is accompanied by problems such as the widening gap between the rich and the poor and serious environmental pollution. To prevent China from falling into the middle-income trap, it is crucial to coordinate economic development with environmental protection and slow down the growth rate, which not only can optimize the product structure, but also can effectively promote China into the ranks of high-income countries [3]. In the new normal stage, economic development is changing from focusing on speed to improving quality, which will inevitably slow down the speed, but improve the quality of economic development to gain more benefits, which will help China’s economy achieve sustainable development overall. The change of China’s economic growth model has also driven China’s economic development from investment-driven to innovation-driven, improving the ability of science and technology innovation, which can improve productivity and has a significant positive effect on the management of environmental pollution and resource conservation [4]. In the context of the new economic normal, this paper studies the interaction between China’s export trade and environmental issues and makes a point of policy suggestion to realize the coordinated development of cement products trade development and environmental governance.In recent years, with the widespread concern of global warming and the increasing pressure on the global ecological environment, scholars from various countries have put forward new terms such as circular economy, environmentally coherent design, and eco-friendly materials, and extensive research has been conducted on the ecological and environmental issues such as implied energy and implied ecological footprint. This provides an alternative way to study the relationship between traditional foreign trade and the ecological environment, that is, from the perspective of final consumption, the analysis of implied carbon and implied pollution in trade import and export products reveals the impact of foreign trade on the environment and thus verifies whether there is pollution transfer and other problems [5]. Therefore, for the current situation of foreign trade in the cement industry of “two highs and one capital,” the impact on the ecological environment can be evaluated qualitatively and quantitatively by using methods such as life cycle assessment (LCA). It is important to analyze the environmental impact of cement foreign trade, formulate relevant policies, adjust its import, and export structure, and improve the process.China is currently facing a slowdown in economic growth, weak profitability in the real economy and declining prices of industrially manufactured goods, and double-digit economic growth has become outdated. In the context of the new normal, supply-side reform is an inevitable choice. The slowdown in China’s economic growth is not a lack of demand, but a change in domestic demand, but the supply side cannot meet the current changes in the demand side, so adjustments should be made on the supply side to make the product structure more optimal to meet the people’s growing needs. At present, profits in industries such as steel and cement have fallen sharply, and some industries are even experiencing losses. Overcapacity has become a roadblock on the road to China’s economic transformation. The oversupply of low and medium value-added products and undersupply of high value-added products has led to an asymmetry between supply and demand, so it is imperative to promote supply-side reform, which requires the Chinese government to actively adjust the export structure and foreign trade growth, eliminate a certain percentage of zombie enterprises with backward capacity, and vigorously support green and clean industries. The economic development has produced environmental problems such as air pollution, serious waste of water resources, and soil erosion, which seriously restrict China to achieve sustainable development. This paper mainly focuses on a descriptive statistical analysis of China’s export trade and environmental pollution, effect analysis of export trade and environmental pollution and environmental regulation, and empirical analysis of the interaction between China’s export trade and environmental problems. Combined with the above argumentation results, this paper proposes some countermeasures to promote the coordinated development of China’s export trade and environment, which is helpful to promote the implementation. It also provides some reference for the coordinated development of export trade and environmental issues in China under the new situation, and has some theoretical significance as well as practical significance.


## 2. Methods and Materials

### 2.1. Current Status of Research

Differences in environmental regulations are an important reason for industrial spatial reconfiguration, if the more stringent level of environmental regulations in the home country will increase the operating costs of enterprises and thus prompt them to move out of the country, the differences in environmental regulations bring about the repositioning of enterprise location choice is to verify the pollution paradise hypothesis [6]. There are three main approaches to study this issue: first, to examine the impact of foreign investment due to differences in environmental regulations in different regions of the host country; second, to examine the impact of foreign investment due to differences in environmental regulations in different industries in the host country; and third, to examine the impact of foreign investment due to differences in environmental regulations in the home and host countries [7–9].Eco-efficiency has the following three connotations: Firstly, eco-efficiency considers both the economic and environmental goals of a business. From a business perspective, it requires the provision of win-win with economic benefits and environmental benefits [10]. Secondly, the input and lower cost to create higher quality products, to achieve the enterprise district city economy to provide integration into the sustainable development of eco-efficiency will be sustainable development as the enterprise’s own goals, to provide an opportunity for the enterprise or regional economy to integrate into the process of sustainable development, industrial enterprises to generate ideas about the environment at the same time to reduce the environmental impact to a minimum, from the guarantee [11]. Thirdly, eco-efficiency requires enterprises to produce high-quality products while reducing environmental impact to a minimum, from the raw materials of the product to the entire process of production and sales, WBCSD points out that the implementation of ecological three heart elements of enterprises to reduce the environment within the limits of self-sustainability [12]. According to the World Business Council for Sustainable Development (WBCSD), there are seven basic principles to be met by enterprises in implementing efficiency: firstly, the intensity of raw material consumption for products and services should be reduced; secondly, the intensity of energy consumption for products and services should be reduced; thirdly, the emission of toxic substances should be reduced; fourth, the recyclability of raw materials should be increased; fifth, the use of renewable resources should be maximized; sixth, the durability of products should be continuously improved; and seventh, the use of products should be increased, and the service intensity of the product should be enhanced gradually. From these seven elements, we can realize the reduction of resource consumption and the gradual reduction of environmental impact, and finally realize the eco-efficiency goal of improving product quality and service [13–15].To sum up, scholars at home and abroad have mainly studied the relationship between export trade and environmental pollution from the three aspects. In this paper, we have combed through the relevant literature on foreign trade and environmental issues, and we can see that in terms of theory, scholars at home and abroad have established the general equilibrium analysis theory and the theory of environmental effects of export trade, etc. In terms of empirical evidence, some scholars have adopted the CGE model, some have established panel data, and some have adopted the input-output approach. However, due to the different ideas and perspectives of each scholar, and the different statistical caliber of data, various conclusions are obtained. It can be found that most scholars only study the single influence relationship between export trade and environmental problems, and few scholars study the influence of the environment on the export trade. Based on previous studies, this paper conducts effect analysis and empirical analysis on the interaction between export trade and environmental problems based on the VAR model, draws conclusions, and puts forward some policy recommendations based on the analysis results.


### 2.2. Granger Causality Analysis of Foreign Trade in Cement Products and Eco-Environmental Design in China

#### 2.2.1. Granger Causality Analysis Model Analysis

By analyzing the current situation of China’s foreign trade in cement products and the current situation of China’s ecological impact, it can be assumed that there is a causal relationship between China’s foreign trade in cement products and the ecological impact [16]. To determine whether there is a causal relationship between the two, and if so, which side is the cause and which side is the effect, the Granger causality test is used to analyze this paper. Granger causality is defined as the variance that depends on the best least squares prediction using all the information at some time point in the past. A prerequisite for Granger causality test is that the time series must be stable, otherwise false regression may occur. Granger causality test assumes that the information about each variable of x and y is included in their time series, and its regression model is shown in the following equations.(1)yt=∑i=1qaixi−1−∑j=1qβixi−1,(2)xt=∑i=1qλiyi−1−∑j=1qδiyi−1.The hypothesis was tested using the postmortem test, i.e.,(3)F=RSSR+RSSU∗qRSSU/n−k.It invites the number of parameters to be estimated in the unconstrained regression of the distribution with and degrees of freedom. The null hypothesis is rejected if the value calculated at the selected significant level exceeds the critical value. By doing the regression ofXt with and without the lagged term through equation (3), respectively, the sum of squared residuals is(4)RSS1=∑i,t=1nXt−i+Xt+i.Linear causality test is not able to determine whether the variables have nonlinear causality, considering the nonlinear model:(5)Xt=βixi−1XXt−i−εi.In this paper, we examine whether there is a causal relationship between the export and import trade of cement products and the ecological environment in China, respectively. Among them, the causal relationship between export trade of cement products and ecological environment is selected to test the export trade volume of our enclosed cement products from 2016 to 2020 and the data of cement industry emissions of wastewater, SO2, dust, soot, solid waste and coal, and electricity consumption; since the pollutant emissions generated during the production of imported cement products are in the producing countries, and the foreign data of cement industry pollutant emissions are difficult to obtain. In this paper, domestic pollutant emission data are used instead to approximate whether there is a causal relationship between the import trade of cement products and the ecological environment, and the data are obtained from the China Statistical Yearbook and EPS Global Statistical Platform in previous years. Granger causality test can be performed for any two variables using Eviews 6.0, and considering both the serial correlation of the test model and the red pool information criterion (AIC), it is found that the lagged 4th order test model does not have 1st order autocorrelation, and the AIC value is small, so the test results at 5% significance level, as shown in Figure 1.Figure 1
Granger causality test results.where EX denotes the export trade volume of Chinese cement products by year, IM denotes the import trade volume of Chinese cement products by year, WW denotes the wastewater emission of the Chinese cement industry by year, SO2 denotes the SO2 emission of the Chinese cement industry by year, SMOKE denotes the soot emission of Chinese cement industry by year, DUST denotes the dust emission of Chinese cement industry by year, SW denotes the solid waste emission of Chinese cement industry by year, COAL indicates the coal consumption of Chinese cement industry by year, and E indicates the electricity consumption of Chinese cement industry by year.As can be seen from Figure2, at the 5% significance level, the lag length is within 3. The export trade of Chinese cement products is the cause of wastewater, SO2, dust, and solid waste emissions, not the cause of soot emissions, while none of the pollutant emissions is the cause of export trade, and the export trade of Chinese cement products and coal and electricity consumption are causal; on the other hand, the import trade of our cement products is the cause of wastewater, SO2, dust, and solid waste emissions, not the cause of soot emissions, while none of the pollutant emissions is the cause of export trade. And the electricity consumption in the producing countries is the cause of import trade of Chinese cement products, and vice versa, and there is no causal relationship between import trade and coal consumption in the producing countries [17]. This result could indicate that the import and export trade of Chinese cement products is the cause of ecological impacts, while changes in the ecological environment may not affect the import and export trade of cement products. This result may be because labor, capital, and resources play a decisive role in the production process of cement products, while the relative influence of the ecological environment is limited, which is particularly evident in the causal relationship between the export trade of Chinese cement products and the ecological environment. The development of the Chinese cement industry lacks a market for effective trading of energy, resource use, and pollution externalities, which largely limits the role of ecology in influencing its foreign trade.Figure 2
Granger causality analysis model.The current situation and problems of China’s ecological environment are introduced, the overview of China’s cement industry and the current situation of foreign trade of cement products are briefly explained, and the role of China’s cement industry in influencing the ecological environment is investigated. The Granger causality test model is used to test whether there is a causal relationship between the foreign trade of Chinese cement products and the ecological environment, and it is concluded that: the export trade of Chinese cement products is the cause of wastewater, SO2, dust, and solid waste emissions, not the cause of soot emissions, while none of the pollutant emissions is the cause of export trade, and the export trade of Chinese cement products. On the other hand, the import trade of Chinese cement products is the cause of wastewater, SO2, dust and solid waste emissions in the producing countries, not the cause of soot emissions, and none of the pollutant emissions in the producing countries is the cause of the import trade, and the electricity consumption in the producing countries is the cause of the import trade of Chinese cement products, otherwise, there is no causal relationship between the import trade and coal consumption in the producing countries [18].Due to the influence of environmental regulations, multinational enterprises are happy to invest and build factories in China, especially at the beginning of the reform and opening because of the forced economic development, China does not pay enough attention to the environment and is pollution-intensive industries have room to survive. The environmental endowment of any country is certain, but the government can choose how many environmental resources to use, so it is also possible to play political games, even if the resource endowment is the same, it will be different because of the amount of use, so the national environmental regulations reflect the number of resources used. If China implements more lenient environmental regulations, then environmental factors are relatively abundant, while if developed countries implement more stringent environmental regulations, then environmental factors are relatively scarce. As mentioned above, the implementation of more stringent environmental regulations in the home country means adding additional production costs, investing more resources to control pollution emissions, or bearing fines for violating pollution limits, such additional expenses for enterprises means losing their competitive advantage, then multinational enterprises will re-strategize the global layout to adjust production costs. Therefore, to reduce production costs, more production projects will be moved to China, where environmental regulations are lax, and then China becomes a pollution haven for developed countries. Therefore, this paper analyzes the pollution paradise hypothesis theory through the cost-benefit model.The industrial distribution of foreign investment is not only in the polluting industries, with the change of China’s investment policy, there are also some high-tech industries new pollution, regardless of which industries, but the important thing is also that China to undertake the link, even if it is a polluting industry, if China is only responsible for the design of R&D or late sales planning and other links, then the environmental impact is very different.


#### 2.2.2. Analysis of Foreign Trade and Ecological Environment of Cement Products in China

Cement production is characterized by seasonality and regional differences, etc. Considering the integrity, repeatability, representativeness, and timeliness of data in life cycle evaluation, the time boundary is defined as one year as one life cycle of cement foreign trade. The research content is spatially uncertain and the spatial boundary is blurred. Considering the differences in cement industry activities, legislative requirements, and consumption habits in different countries and regions, this paper divides the life cycle of foreign trade of cement products into two parts, one for the import of cement products and the other for the export of cement products. In these two parts of the study, to make the research findings general and to simplify the calculation, “import dummy countries” and “export dummy countries” are set up, respectively, and the data related to the main import and export countries of cement in China are analyzed comprehensively from 2016 to 2020. The main import and export countries (regions) of Chinese cement products and the corresponding import and export volume data in 2020. Cement products have a complete life cycle starting from the extraction of raw materials, through production, use, and finally disposal, but the use and disposal stages of cement are a long process with little geographical variation in its environmental impact, and given that the main study of this paper is the life cycle of cement foreign trade, the scope of this study is defined as the extraction of raw materials, the ecological impact of production, processing, and transportation of finished cement products, and the environmental impact of cement use and disposal [19]. The impact of cement use and disposal is not included in the scope of this study.The functional unit determines the scale for comparing products and thus allows the standardization of inputs and outputs of a product system, so the functional unit must be clearly defined and measurable. In this paper, considering the production efficiency, service life, and quality standard of cement, P.O.42.5 cement with high LT production and wide application is selected as a functional unit. This functional unit can express the serviceability of cement and is comparable with international cement products, so it is appropriate to be applied in the study of foreign trade. Based on the determination of the functional unit, the composition of the baseline flow needs to be determined for characterizing the inputs and outputs of the system. The system boundary is shown in Figure3.Figure 3
System boundary.The cement industry not only consumes huge amounts of energy and resources but also seriously pollutes the environment. The cement production process inevitably consumes energy and resources and emits pollutants such as waste gas and dust. This requires the identification of the main environmental impact factors of the cement industry. Currently, the main pollutants in the cement industry are soot and dust, which are characterized by large emissions and many emission points, CO2, and NO, which are also the main pollutants in the cement industry. The new dry cement process does not produce industrial wastewater directly, but mainly cooling water for equipment, which can be recycled. The cement industry not only produces and discharges less solid waste but also can conditionally use coal gangue, slag, and fly ash as alternative raw materials and fuels. According to this analysis, the environmental impact factors of this study are dust, CO2, SO2, and NOx.Inventory analysis is the process of collecting qualitative or definitive input and output data from a production system and quantifying the data by performing calculations. It includes the process of collecting and calculating data to quantify the inputs and outputs of a product system. The inputs and outputs mainly include the use of resources and emissions to air, water, and land associated with the system, which can be interpreted according to the purpose and scope of the evaluation based on the above data quality requirements and are also used as input components for the LCA. It is usually divided into four stages: determining the functional units, describing the internal processes of the system, collecting data, and processing data. It is necessary to collect data to be included in the inventory for each unit process within the system boundary, including both qualitative and quantitative. The process of collecting data varies depending on the unit process and its purpose and scope. The following is an analysis of the ecological impact inventory for each stage in the life cycle of cement products sub-export and import.The system shown in Figure4 is separated from the system boundary that surrounds it, and the system environment outside the boundary is both the source and sink of all inputs to the system and all outputs. To describe the specific processes of the model and the types of data associated with them, process flow diagrams are drawn, as shown in Figure 4.Figure 4
Cement production flow chart.Raw material extraction stage, using Di Xianghua calculated by China’s resources and energy production of life-cycle emissions data to calculate pollution emissions data [20]. In the stage of raw material transportation and energy and resource production, the pollutant emission data of China’s common process is used to calculate by multiplying the corresponding raw material and energy consumption, and the list of the main raw material and energy consumption of import and export cement products with the transportation method and the basic data of pollutant emission of common process. In the production stage of cement products, the data of dust emission is calculated by the ratio of the data after dust removal treatment and dust removal efficiency; the emission data of SO2 and NO are obtained from monitoring data; the emission of CO2 is usually not monitored, so the emission of CO2 is calculated by the empirical formula. The import and export of cement products in China are mainly through waterways, and the ecological impact of import and export of cement products per unit function can be calculated from the pollutant emission data of waterways.External managers decide certain requirements of the design according to the market situation (product performance requirements, environmental policy requirements, market price requirements, etc.), and then internal design managers put forward the conceptual framework of the design according to the external requirements combined with their actual situation and development purposes, and then hand over to the designers to complete the detailed technical process design. The whole process is regulated and coordinated by the three parties, and the final design plan is decided by the external managers after several mutual feedbacks. The research and development design of environmental materials is the issue of environmental design of materials. It takes the strategy of sustainable development of the material industry as the starting point and takes into consideration the environmental compatibility, economy, and functionality of the material during the whole life cycle from the design stage of the material, and balances each other, to make its comprehensive performance index reach the standard of environmental material.


## 2.1. Current Status of Research

Differences in environmental regulations are an important reason for industrial spatial reconfiguration, if the more stringent level of environmental regulations in the home country will increase the operating costs of enterprises and thus prompt them to move out of the country, the differences in environmental regulations bring about the repositioning of enterprise location choice is to verify the pollution paradise hypothesis [6]. There are three main approaches to study this issue: first, to examine the impact of foreign investment due to differences in environmental regulations in different regions of the host country; second, to examine the impact of foreign investment due to differences in environmental regulations in different industries in the host country; and third, to examine the impact of foreign investment due to differences in environmental regulations in the home and host countries [7–9].Eco-efficiency has the following three connotations: Firstly, eco-efficiency considers both the economic and environmental goals of a business. From a business perspective, it requires the provision of win-win with economic benefits and environmental benefits [10]. Secondly, the input and lower cost to create higher quality products, to achieve the enterprise district city economy to provide integration into the sustainable development of eco-efficiency will be sustainable development as the enterprise’s own goals, to provide an opportunity for the enterprise or regional economy to integrate into the process of sustainable development, industrial enterprises to generate ideas about the environment at the same time to reduce the environmental impact to a minimum, from the guarantee [11]. Thirdly, eco-efficiency requires enterprises to produce high-quality products while reducing environmental impact to a minimum, from the raw materials of the product to the entire process of production and sales, WBCSD points out that the implementation of ecological three heart elements of enterprises to reduce the environment within the limits of self-sustainability [12]. According to the World Business Council for Sustainable Development (WBCSD), there are seven basic principles to be met by enterprises in implementing efficiency: firstly, the intensity of raw material consumption for products and services should be reduced; secondly, the intensity of energy consumption for products and services should be reduced; thirdly, the emission of toxic substances should be reduced; fourth, the recyclability of raw materials should be increased; fifth, the use of renewable resources should be maximized; sixth, the durability of products should be continuously improved; and seventh, the use of products should be increased, and the service intensity of the product should be enhanced gradually. From these seven elements, we can realize the reduction of resource consumption and the gradual reduction of environmental impact, and finally realize the eco-efficiency goal of improving product quality and service [13–15].To sum up, scholars at home and abroad have mainly studied the relationship between export trade and environmental pollution from the three aspects. In this paper, we have combed through the relevant literature on foreign trade and environmental issues, and we can see that in terms of theory, scholars at home and abroad have established the general equilibrium analysis theory and the theory of environmental effects of export trade, etc. In terms of empirical evidence, some scholars have adopted the CGE model, some have established panel data, and some have adopted the input-output approach. However, due to the different ideas and perspectives of each scholar, and the different statistical caliber of data, various conclusions are obtained. It can be found that most scholars only study the single influence relationship between export trade and environmental problems, and few scholars study the influence of the environment on the export trade. Based on previous studies, this paper conducts effect analysis and empirical analysis on the interaction between export trade and environmental problems based on the VAR model, draws conclusions, and puts forward some policy recommendations based on the analysis results.


## 2.2. Granger Causality Analysis of Foreign Trade in Cement Products and Eco-Environmental Design in China

### 2.2.1. Granger Causality Analysis Model Analysis

By analyzing the current situation of China’s foreign trade in cement products and the current situation of China’s ecological impact, it can be assumed that there is a causal relationship between China’s foreign trade in cement products and the ecological impact [16]. To determine whether there is a causal relationship between the two, and if so, which side is the cause and which side is the effect, the Granger causality test is used to analyze this paper. Granger causality is defined as the variance that depends on the best least squares prediction using all the information at some time point in the past. A prerequisite for Granger causality test is that the time series must be stable, otherwise false regression may occur. Granger causality test assumes that the information about each variable of x and y is included in their time series, and its regression model is shown in the following equations.(1)yt=∑i=1qaixi−1−∑j=1qβixi−1,(2)xt=∑i=1qλiyi−1−∑j=1qδiyi−1.The hypothesis was tested using the postmortem test, i.e.,(3)F=RSSR+RSSU∗qRSSU/n−k.It invites the number of parameters to be estimated in the unconstrained regression of the distribution with and degrees of freedom. The null hypothesis is rejected if the value calculated at the selected significant level exceeds the critical value. By doing the regression ofXt with and without the lagged term through equation (3), respectively, the sum of squared residuals is(4)RSS1=∑i,t=1nXt−i+Xt+i.Linear causality test is not able to determine whether the variables have nonlinear causality, considering the nonlinear model:(5)Xt=βixi−1XXt−i−εi.In this paper, we examine whether there is a causal relationship between the export and import trade of cement products and the ecological environment in China, respectively. Among them, the causal relationship between export trade of cement products and ecological environment is selected to test the export trade volume of our enclosed cement products from 2016 to 2020 and the data of cement industry emissions of wastewater, SO2, dust, soot, solid waste and coal, and electricity consumption; since the pollutant emissions generated during the production of imported cement products are in the producing countries, and the foreign data of cement industry pollutant emissions are difficult to obtain. In this paper, domestic pollutant emission data are used instead to approximate whether there is a causal relationship between the import trade of cement products and the ecological environment, and the data are obtained from the China Statistical Yearbook and EPS Global Statistical Platform in previous years. Granger causality test can be performed for any two variables using Eviews 6.0, and considering both the serial correlation of the test model and the red pool information criterion (AIC), it is found that the lagged 4th order test model does not have 1st order autocorrelation, and the AIC value is small, so the test results at 5% significance level, as shown in Figure 1.Figure 1
Granger causality test results.where EX denotes the export trade volume of Chinese cement products by year, IM denotes the import trade volume of Chinese cement products by year, WW denotes the wastewater emission of the Chinese cement industry by year, SO2 denotes the SO2 emission of the Chinese cement industry by year, SMOKE denotes the soot emission of Chinese cement industry by year, DUST denotes the dust emission of Chinese cement industry by year, SW denotes the solid waste emission of Chinese cement industry by year, COAL indicates the coal consumption of Chinese cement industry by year, and E indicates the electricity consumption of Chinese cement industry by year.As can be seen from Figure2, at the 5% significance level, the lag length is within 3. The export trade of Chinese cement products is the cause of wastewater, SO2, dust, and solid waste emissions, not the cause of soot emissions, while none of the pollutant emissions is the cause of export trade, and the export trade of Chinese cement products and coal and electricity consumption are causal; on the other hand, the import trade of our cement products is the cause of wastewater, SO2, dust, and solid waste emissions, not the cause of soot emissions, while none of the pollutant emissions is the cause of export trade. And the electricity consumption in the producing countries is the cause of import trade of Chinese cement products, and vice versa, and there is no causal relationship between import trade and coal consumption in the producing countries [17]. This result could indicate that the import and export trade of Chinese cement products is the cause of ecological impacts, while changes in the ecological environment may not affect the import and export trade of cement products. This result may be because labor, capital, and resources play a decisive role in the production process of cement products, while the relative influence of the ecological environment is limited, which is particularly evident in the causal relationship between the export trade of Chinese cement products and the ecological environment. The development of the Chinese cement industry lacks a market for effective trading of energy, resource use, and pollution externalities, which largely limits the role of ecology in influencing its foreign trade.Figure 2
Granger causality analysis model.The current situation and problems of China’s ecological environment are introduced, the overview of China’s cement industry and the current situation of foreign trade of cement products are briefly explained, and the role of China’s cement industry in influencing the ecological environment is investigated. The Granger causality test model is used to test whether there is a causal relationship between the foreign trade of Chinese cement products and the ecological environment, and it is concluded that: the export trade of Chinese cement products is the cause of wastewater, SO2, dust, and solid waste emissions, not the cause of soot emissions, while none of the pollutant emissions is the cause of export trade, and the export trade of Chinese cement products. On the other hand, the import trade of Chinese cement products is the cause of wastewater, SO2, dust and solid waste emissions in the producing countries, not the cause of soot emissions, and none of the pollutant emissions in the producing countries is the cause of the import trade, and the electricity consumption in the producing countries is the cause of the import trade of Chinese cement products, otherwise, there is no causal relationship between the import trade and coal consumption in the producing countries [18].Due to the influence of environmental regulations, multinational enterprises are happy to invest and build factories in China, especially at the beginning of the reform and opening because of the forced economic development, China does not pay enough attention to the environment and is pollution-intensive industries have room to survive. The environmental endowment of any country is certain, but the government can choose how many environmental resources to use, so it is also possible to play political games, even if the resource endowment is the same, it will be different because of the amount of use, so the national environmental regulations reflect the number of resources used. If China implements more lenient environmental regulations, then environmental factors are relatively abundant, while if developed countries implement more stringent environmental regulations, then environmental factors are relatively scarce. As mentioned above, the implementation of more stringent environmental regulations in the home country means adding additional production costs, investing more resources to control pollution emissions, or bearing fines for violating pollution limits, such additional expenses for enterprises means losing their competitive advantage, then multinational enterprises will re-strategize the global layout to adjust production costs. Therefore, to reduce production costs, more production projects will be moved to China, where environmental regulations are lax, and then China becomes a pollution haven for developed countries. Therefore, this paper analyzes the pollution paradise hypothesis theory through the cost-benefit model.The industrial distribution of foreign investment is not only in the polluting industries, with the change of China’s investment policy, there are also some high-tech industries new pollution, regardless of which industries, but the important thing is also that China to undertake the link, even if it is a polluting industry, if China is only responsible for the design of R&D or late sales planning and other links, then the environmental impact is very different.


### 2.2.2. Analysis of Foreign Trade and Ecological Environment of Cement Products in China

Cement production is characterized by seasonality and regional differences, etc. Considering the integrity, repeatability, representativeness, and timeliness of data in life cycle evaluation, the time boundary is defined as one year as one life cycle of cement foreign trade. The research content is spatially uncertain and the spatial boundary is blurred. Considering the differences in cement industry activities, legislative requirements, and consumption habits in different countries and regions, this paper divides the life cycle of foreign trade of cement products into two parts, one for the import of cement products and the other for the export of cement products. In these two parts of the study, to make the research findings general and to simplify the calculation, “import dummy countries” and “export dummy countries” are set up, respectively, and the data related to the main import and export countries of cement in China are analyzed comprehensively from 2016 to 2020. The main import and export countries (regions) of Chinese cement products and the corresponding import and export volume data in 2020. Cement products have a complete life cycle starting from the extraction of raw materials, through production, use, and finally disposal, but the use and disposal stages of cement are a long process with little geographical variation in its environmental impact, and given that the main study of this paper is the life cycle of cement foreign trade, the scope of this study is defined as the extraction of raw materials, the ecological impact of production, processing, and transportation of finished cement products, and the environmental impact of cement use and disposal [19]. The impact of cement use and disposal is not included in the scope of this study.The functional unit determines the scale for comparing products and thus allows the standardization of inputs and outputs of a product system, so the functional unit must be clearly defined and measurable. In this paper, considering the production efficiency, service life, and quality standard of cement, P.O.42.5 cement with high LT production and wide application is selected as a functional unit. This functional unit can express the serviceability of cement and is comparable with international cement products, so it is appropriate to be applied in the study of foreign trade. Based on the determination of the functional unit, the composition of the baseline flow needs to be determined for characterizing the inputs and outputs of the system. The system boundary is shown in Figure3.Figure 3
System boundary.The cement industry not only consumes huge amounts of energy and resources but also seriously pollutes the environment. The cement production process inevitably consumes energy and resources and emits pollutants such as waste gas and dust. This requires the identification of the main environmental impact factors of the cement industry. Currently, the main pollutants in the cement industry are soot and dust, which are characterized by large emissions and many emission points, CO2, and NO, which are also the main pollutants in the cement industry. The new dry cement process does not produce industrial wastewater directly, but mainly cooling water for equipment, which can be recycled. The cement industry not only produces and discharges less solid waste but also can conditionally use coal gangue, slag, and fly ash as alternative raw materials and fuels. According to this analysis, the environmental impact factors of this study are dust, CO2, SO2, and NOx.Inventory analysis is the process of collecting qualitative or definitive input and output data from a production system and quantifying the data by performing calculations. It includes the process of collecting and calculating data to quantify the inputs and outputs of a product system. The inputs and outputs mainly include the use of resources and emissions to air, water, and land associated with the system, which can be interpreted according to the purpose and scope of the evaluation based on the above data quality requirements and are also used as input components for the LCA. It is usually divided into four stages: determining the functional units, describing the internal processes of the system, collecting data, and processing data. It is necessary to collect data to be included in the inventory for each unit process within the system boundary, including both qualitative and quantitative. The process of collecting data varies depending on the unit process and its purpose and scope. The following is an analysis of the ecological impact inventory for each stage in the life cycle of cement products sub-export and import.The system shown in Figure4 is separated from the system boundary that surrounds it, and the system environment outside the boundary is both the source and sink of all inputs to the system and all outputs. To describe the specific processes of the model and the types of data associated with them, process flow diagrams are drawn, as shown in Figure 4.Figure 4
Cement production flow chart.Raw material extraction stage, using Di Xianghua calculated by China’s resources and energy production of life-cycle emissions data to calculate pollution emissions data [20]. In the stage of raw material transportation and energy and resource production, the pollutant emission data of China’s common process is used to calculate by multiplying the corresponding raw material and energy consumption, and the list of the main raw material and energy consumption of import and export cement products with the transportation method and the basic data of pollutant emission of common process. In the production stage of cement products, the data of dust emission is calculated by the ratio of the data after dust removal treatment and dust removal efficiency; the emission data of SO2 and NO are obtained from monitoring data; the emission of CO2 is usually not monitored, so the emission of CO2 is calculated by the empirical formula. The import and export of cement products in China are mainly through waterways, and the ecological impact of import and export of cement products per unit function can be calculated from the pollutant emission data of waterways.External managers decide certain requirements of the design according to the market situation (product performance requirements, environmental policy requirements, market price requirements, etc.), and then internal design managers put forward the conceptual framework of the design according to the external requirements combined with their actual situation and development purposes, and then hand over to the designers to complete the detailed technical process design. The whole process is regulated and coordinated by the three parties, and the final design plan is decided by the external managers after several mutual feedbacks. The research and development design of environmental materials is the issue of environmental design of materials. It takes the strategy of sustainable development of the material industry as the starting point and takes into consideration the environmental compatibility, economy, and functionality of the material during the whole life cycle from the design stage of the material, and balances each other, to make its comprehensive performance index reach the standard of environmental material.


## 2.2.1. Granger Causality Analysis Model Analysis

By analyzing the current situation of China’s foreign trade in cement products and the current situation of China’s ecological impact, it can be assumed that there is a causal relationship between China’s foreign trade in cement products and the ecological impact [16]. To determine whether there is a causal relationship between the two, and if so, which side is the cause and which side is the effect, the Granger causality test is used to analyze this paper. Granger causality is defined as the variance that depends on the best least squares prediction using all the information at some time point in the past. A prerequisite for Granger causality test is that the time series must be stable, otherwise false regression may occur. Granger causality test assumes that the information about each variable of x and y is included in their time series, and its regression model is shown in the following equations.(1)yt=∑i=1qaixi−1−∑j=1qβixi−1,(2)xt=∑i=1qλiyi−1−∑j=1qδiyi−1.The hypothesis was tested using the postmortem test, i.e.,(3)F=RSSR+RSSU∗qRSSU/n−k.It invites the number of parameters to be estimated in the unconstrained regression of the distribution with and degrees of freedom. The null hypothesis is rejected if the value calculated at the selected significant level exceeds the critical value. By doing the regression ofXt with and without the lagged term through equation (3), respectively, the sum of squared residuals is(4)RSS1=∑i,t=1nXt−i+Xt+i.Linear causality test is not able to determine whether the variables have nonlinear causality, considering the nonlinear model:(5)Xt=βixi−1XXt−i−εi.In this paper, we examine whether there is a causal relationship between the export and import trade of cement products and the ecological environment in China, respectively. Among them, the causal relationship between export trade of cement products and ecological environment is selected to test the export trade volume of our enclosed cement products from 2016 to 2020 and the data of cement industry emissions of wastewater, SO2, dust, soot, solid waste and coal, and electricity consumption; since the pollutant emissions generated during the production of imported cement products are in the producing countries, and the foreign data of cement industry pollutant emissions are difficult to obtain. In this paper, domestic pollutant emission data are used instead to approximate whether there is a causal relationship between the import trade of cement products and the ecological environment, and the data are obtained from the China Statistical Yearbook and EPS Global Statistical Platform in previous years. Granger causality test can be performed for any two variables using Eviews 6.0, and considering both the serial correlation of the test model and the red pool information criterion (AIC), it is found that the lagged 4th order test model does not have 1st order autocorrelation, and the AIC value is small, so the test results at 5% significance level, as shown in Figure 1.Figure 1
Granger causality test results.where EX denotes the export trade volume of Chinese cement products by year, IM denotes the import trade volume of Chinese cement products by year, WW denotes the wastewater emission of the Chinese cement industry by year, SO2 denotes the SO2 emission of the Chinese cement industry by year, SMOKE denotes the soot emission of Chinese cement industry by year, DUST denotes the dust emission of Chinese cement industry by year, SW denotes the solid waste emission of Chinese cement industry by year, COAL indicates the coal consumption of Chinese cement industry by year, and E indicates the electricity consumption of Chinese cement industry by year.As can be seen from Figure2, at the 5% significance level, the lag length is within 3. The export trade of Chinese cement products is the cause of wastewater, SO2, dust, and solid waste emissions, not the cause of soot emissions, while none of the pollutant emissions is the cause of export trade, and the export trade of Chinese cement products and coal and electricity consumption are causal; on the other hand, the import trade of our cement products is the cause of wastewater, SO2, dust, and solid waste emissions, not the cause of soot emissions, while none of the pollutant emissions is the cause of export trade. And the electricity consumption in the producing countries is the cause of import trade of Chinese cement products, and vice versa, and there is no causal relationship between import trade and coal consumption in the producing countries [17]. This result could indicate that the import and export trade of Chinese cement products is the cause of ecological impacts, while changes in the ecological environment may not affect the import and export trade of cement products. This result may be because labor, capital, and resources play a decisive role in the production process of cement products, while the relative influence of the ecological environment is limited, which is particularly evident in the causal relationship between the export trade of Chinese cement products and the ecological environment. The development of the Chinese cement industry lacks a market for effective trading of energy, resource use, and pollution externalities, which largely limits the role of ecology in influencing its foreign trade.Figure 2
Granger causality analysis model.The current situation and problems of China’s ecological environment are introduced, the overview of China’s cement industry and the current situation of foreign trade of cement products are briefly explained, and the role of China’s cement industry in influencing the ecological environment is investigated. The Granger causality test model is used to test whether there is a causal relationship between the foreign trade of Chinese cement products and the ecological environment, and it is concluded that: the export trade of Chinese cement products is the cause of wastewater, SO2, dust, and solid waste emissions, not the cause of soot emissions, while none of the pollutant emissions is the cause of export trade, and the export trade of Chinese cement products. On the other hand, the import trade of Chinese cement products is the cause of wastewater, SO2, dust and solid waste emissions in the producing countries, not the cause of soot emissions, and none of the pollutant emissions in the producing countries is the cause of the import trade, and the electricity consumption in the producing countries is the cause of the import trade of Chinese cement products, otherwise, there is no causal relationship between the import trade and coal consumption in the producing countries [18].Due to the influence of environmental regulations, multinational enterprises are happy to invest and build factories in China, especially at the beginning of the reform and opening because of the forced economic development, China does not pay enough attention to the environment and is pollution-intensive industries have room to survive. The environmental endowment of any country is certain, but the government can choose how many environmental resources to use, so it is also possible to play political games, even if the resource endowment is the same, it will be different because of the amount of use, so the national environmental regulations reflect the number of resources used. If China implements more lenient environmental regulations, then environmental factors are relatively abundant, while if developed countries implement more stringent environmental regulations, then environmental factors are relatively scarce. As mentioned above, the implementation of more stringent environmental regulations in the home country means adding additional production costs, investing more resources to control pollution emissions, or bearing fines for violating pollution limits, such additional expenses for enterprises means losing their competitive advantage, then multinational enterprises will re-strategize the global layout to adjust production costs. Therefore, to reduce production costs, more production projects will be moved to China, where environmental regulations are lax, and then China becomes a pollution haven for developed countries. Therefore, this paper analyzes the pollution paradise hypothesis theory through the cost-benefit model.The industrial distribution of foreign investment is not only in the polluting industries, with the change of China’s investment policy, there are also some high-tech industries new pollution, regardless of which industries, but the important thing is also that China to undertake the link, even if it is a polluting industry, if China is only responsible for the design of R&D or late sales planning and other links, then the environmental impact is very different.


## 2.2.2. Analysis of Foreign Trade and Ecological Environment of Cement Products in China

Cement production is characterized by seasonality and regional differences, etc. Considering the integrity, repeatability, representativeness, and timeliness of data in life cycle evaluation, the time boundary is defined as one year as one life cycle of cement foreign trade. The research content is spatially uncertain and the spatial boundary is blurred. Considering the differences in cement industry activities, legislative requirements, and consumption habits in different countries and regions, this paper divides the life cycle of foreign trade of cement products into two parts, one for the import of cement products and the other for the export of cement products. In these two parts of the study, to make the research findings general and to simplify the calculation, “import dummy countries” and “export dummy countries” are set up, respectively, and the data related to the main import and export countries of cement in China are analyzed comprehensively from 2016 to 2020. The main import and export countries (regions) of Chinese cement products and the corresponding import and export volume data in 2020. Cement products have a complete life cycle starting from the extraction of raw materials, through production, use, and finally disposal, but the use and disposal stages of cement are a long process with little geographical variation in its environmental impact, and given that the main study of this paper is the life cycle of cement foreign trade, the scope of this study is defined as the extraction of raw materials, the ecological impact of production, processing, and transportation of finished cement products, and the environmental impact of cement use and disposal [19]. The impact of cement use and disposal is not included in the scope of this study.The functional unit determines the scale for comparing products and thus allows the standardization of inputs and outputs of a product system, so the functional unit must be clearly defined and measurable. In this paper, considering the production efficiency, service life, and quality standard of cement, P.O.42.5 cement with high LT production and wide application is selected as a functional unit. This functional unit can express the serviceability of cement and is comparable with international cement products, so it is appropriate to be applied in the study of foreign trade. Based on the determination of the functional unit, the composition of the baseline flow needs to be determined for characterizing the inputs and outputs of the system. The system boundary is shown in Figure3.Figure 3
System boundary.The cement industry not only consumes huge amounts of energy and resources but also seriously pollutes the environment. The cement production process inevitably consumes energy and resources and emits pollutants such as waste gas and dust. This requires the identification of the main environmental impact factors of the cement industry. Currently, the main pollutants in the cement industry are soot and dust, which are characterized by large emissions and many emission points, CO2, and NO, which are also the main pollutants in the cement industry. The new dry cement process does not produce industrial wastewater directly, but mainly cooling water for equipment, which can be recycled. The cement industry not only produces and discharges less solid waste but also can conditionally use coal gangue, slag, and fly ash as alternative raw materials and fuels. According to this analysis, the environmental impact factors of this study are dust, CO2, SO2, and NOx.Inventory analysis is the process of collecting qualitative or definitive input and output data from a production system and quantifying the data by performing calculations. It includes the process of collecting and calculating data to quantify the inputs and outputs of a product system. The inputs and outputs mainly include the use of resources and emissions to air, water, and land associated with the system, which can be interpreted according to the purpose and scope of the evaluation based on the above data quality requirements and are also used as input components for the LCA. It is usually divided into four stages: determining the functional units, describing the internal processes of the system, collecting data, and processing data. It is necessary to collect data to be included in the inventory for each unit process within the system boundary, including both qualitative and quantitative. The process of collecting data varies depending on the unit process and its purpose and scope. The following is an analysis of the ecological impact inventory for each stage in the life cycle of cement products sub-export and import.The system shown in Figure4 is separated from the system boundary that surrounds it, and the system environment outside the boundary is both the source and sink of all inputs to the system and all outputs. To describe the specific processes of the model and the types of data associated with them, process flow diagrams are drawn, as shown in Figure 4.Figure 4
Cement production flow chart.Raw material extraction stage, using Di Xianghua calculated by China’s resources and energy production of life-cycle emissions data to calculate pollution emissions data [20]. In the stage of raw material transportation and energy and resource production, the pollutant emission data of China’s common process is used to calculate by multiplying the corresponding raw material and energy consumption, and the list of the main raw material and energy consumption of import and export cement products with the transportation method and the basic data of pollutant emission of common process. In the production stage of cement products, the data of dust emission is calculated by the ratio of the data after dust removal treatment and dust removal efficiency; the emission data of SO2 and NO are obtained from monitoring data; the emission of CO2 is usually not monitored, so the emission of CO2 is calculated by the empirical formula. The import and export of cement products in China are mainly through waterways, and the ecological impact of import and export of cement products per unit function can be calculated from the pollutant emission data of waterways.External managers decide certain requirements of the design according to the market situation (product performance requirements, environmental policy requirements, market price requirements, etc.), and then internal design managers put forward the conceptual framework of the design according to the external requirements combined with their actual situation and development purposes, and then hand over to the designers to complete the detailed technical process design. The whole process is regulated and coordinated by the three parties, and the final design plan is decided by the external managers after several mutual feedbacks. The research and development design of environmental materials is the issue of environmental design of materials. It takes the strategy of sustainable development of the material industry as the starting point and takes into consideration the environmental compatibility, economy, and functionality of the material during the whole life cycle from the design stage of the material, and balances each other, to make its comprehensive performance index reach the standard of environmental material.


## 3. Results

### 3.1. Multivariate Nonlinear Granger Causality Test Results

To verify the feasibility of the data sharpening method, we first investigate from bivariate data, two sets of data are selected for simulation,η values are taken at equal spacing on [−1, 1], ε is the number of n randomly generated from a normal distribution with mean 0 and variance 1, y=sin4π−ε, n = 300, these two sets of data have a nonlinear causal relationship, first use Leave-one-out cross-validation (Leave-one-out), to obtain the optimal bandwidth, the bandwidth graph is shown in Figure 5. Leave-one-out means that only one item in the original sample is used as verification data, while the rest is left as training data. This step continues until each sample is treated as validation data.Figure 5
Cross-validation bandwidth map.The optimal bandwidth ℎ = 0.04 is obtained from the bandwidth graph, and then the data is sharpened using the Nadaraya–Watson estimation-based data sharpening method to obtain the sharpened graph. From the sharpened data graph, we can see that the estimated red dashed line based on the Nadaraya–Watson estimation method is different from the original data, and the first and third wave peaks are lower than the original data after sharpening. Therefore, we can use the data sharpening method to reduce the model error and obtain more accurate results (Figure6).Figure 6
Data sharpening graph.The residuals of the bivariate and eight-variate data filtered with the VAR model are then examined using the nonlinear NKTN causality test. Finally, the residuals are tested with the symmetric GARCH-BEKK model and APARCH model after filtering the volatility data to obtain the unidirectional and bidirectional causality of RMB exchange rate changes. It is found that the causal relationship between the variables decreases with the filtering method, indicating that there is a causal relationship between the residuals and volatility. To reduce the error in the multivariate causality test, we use the data sharpening method, which is to obtain new data by acting on the data with a high-dimensional kernel function. In this paper, we propose the approximate test statistic QNKTN and its limiting distribution based on the research method in Diks and Wolski [21] and the data sharpening method. The nonlinear QNKTN causality test yields nonlinear causality not detected by the nonlinear NKTN causality test, which validates the feasibility of the QNKTN statistic and its limiting distribution, and illustrates that the data sharpening method enhances the performance of the multivariate causality test.The numerical simulations and empirical analyses in this paper verify the feasibility of data sharpening methods for multivariate nonlinear Granger causality tests, and the performance of nonlinear QNKTN causality tests is enhanced by data sharpening. We can use the data sharpening method to effectively reduce the bias of multivariate nonlinear Granger causality test, and we also need to further investigate the application of the data sharpening method in nonlinear Granger causality test for multidimensional data such as 3D and 4D data. For the linear Granger causality test, we compare the study of linear Granger causality with the study of nonlinear Granger causality. The bivariate and eight-variate tests of linear causality are applied to the raw data of RMB exchange rate changes using the linear Granger causality test. The linear relationship is then filtered by the VAR model on the raw data and the residuals are subjected to the linear Granger causality test to obtain the causal factors. Finally, the residuals were filtered by symmetric GARCH-BEKK model and APARCH model to examine the change in causality after filtering volatility, and the relationship and causes of exchange rate changes were studied from multiple methods and perspectives to obtain the most direct linear causality between variables.


### 3.2. Impact Evaluation Results

Since the results of such an analysis alone do not give an overall picture of the ecological coherence of each situation, standardization of the various ecological impacts is also required. The purpose of standardizing the parameter results is to better recognize the relative magnitude of each parameter result in the product system under study. This step is the process of calculating the results of the type parameter calculations by dividing them with the very quasi-values. After standardization, the ranking of the equivalent values caused by each ecological impact category of cement product foreign trade is GWP > ADP > AP > NP > POCP > HT, which indicates that the global warming effect is the largest among the ecological impacts caused by cement product foreign trade, followed by the nonrenewable resource consumption and effects. Comparing the eco-environmental impacts of import and export of cement products, the total eco-environmental impact equivalent value of an exported unit of cement products is 16.41% more than that of imported, among which ADP is 3.22% more; GWP is 23.51% more; POCP is 9.98% less; AP is 3.35% less; NP is 11.33% less; HT is 42.88% more.The relative index of ecological impact can be expressed in terms of the ratio of the number of ecological impact equivalents to the total number of ecological impact equivalents corresponding to the entire study area. According to the formula of the relative index of eco-environmental impact, the characteristic knot of the eco-environmental impact of each functional unit of cement product foreign trade can be standardized, and the results are shown in Figure7.Figure 7
Ecological and environmental impact equivalents of foreign trade in cement products.After the standardization of ecological impacts, it is necessary to determine the weight coefficients of each ecological impact, and then obtain the specific environmental impact values. The standardized ecological impact types can be theoretically summed up by unifying the scale and reference standard, and thus the overall ecological coordination can be quantitatively analyzed. Given the different importance of each ecological impact type, the relative weights of each ecological impact type should be determined. The weighted evaluation uses value-based coefficients to convert the index values of each ecological impact type and then combines the parameter results. Since there is no fixed method to determine the weighting factors because it is not very mature yet, the common methods include the expert method, hierarchical analysis, and linear regression equation method. In this paper, the combination of hierarchical analysis and expert method is used to determine the weights. The principle of the abbreviated method of hierarchical analysis is based on experimental data and expert opinion to determine the relative importance of each ecological impact type, then, with the help of matrix operations to derive the relative weight coefficients of each ecological impact type, and finally, the weighted sum to determine the total ecological impact index. Based on the comprehensive analysis of existing cement environmental compatibility evaluation reports and relevant public publications, and combined with expert opinions, the importance scales of cement production eco-environmental impact types are determined in this paper. The relative importance scale used in this paper is shown in Figure8.Figure 8
Ecological impact type desirability scale.The sum of the impact ratios of ADP and GWP both exceed 96%. This indicates that the impact on nonrenewable resource depletion and global warming is still the largest among the ecological impacts of foreign trade in cement products, followed by acidification, with little impact on photochemical ozone formation, eutrophication, and human health damage. From Figure8, it can also be concluded that the total eco-environmental impact equivalent value of exported cement products per unit function is 16.00% more than that of imported ones, including 10.31% more ADP; 23.50% more GWP; 10.16% less POCP; 3.33% less AP; 11.43% less NP; and 60.00% more HT. Due to the high solid waste recycling rate of imported cement products, not only the amount of limestone is saved, but also the raw mill output is increased, the crushing and grinding of limestone are greatly reduced, and the consumption of electricity and coal is correspondingly reduced, which makes the consumption of nonrenewable resources decrease. In addition, the reduction of limestone consumption leads to further reduction of CO generated by calcium carbonate decomposition, and thus the impact on the country is also reduced.In addition, according to the model of the AGP method, ADP corresponds to the resource consumption coefficient, and GWP, POCP, APNP, and HT corresponds to the environmental impact load. The resource consumption coefficient of imported trade is 23.626 and the environmental impact load is 24.581, accounting for 49.01% and 50.99% of the total ecological impact of imported trade, respectively; the total resource consumption coefficient of foreign trade is 49.689 and the total environmental impact load is 54.439, accounting for 47.72% and 52.28% of the total ecological impact index, respectively.


## 3.1. Multivariate Nonlinear Granger Causality Test Results

To verify the feasibility of the data sharpening method, we first investigate from bivariate data, two sets of data are selected for simulation,η values are taken at equal spacing on [−1, 1], ε is the number of n randomly generated from a normal distribution with mean 0 and variance 1, y=sin4π−ε, n = 300, these two sets of data have a nonlinear causal relationship, first use Leave-one-out cross-validation (Leave-one-out), to obtain the optimal bandwidth, the bandwidth graph is shown in Figure 5. Leave-one-out means that only one item in the original sample is used as verification data, while the rest is left as training data. This step continues until each sample is treated as validation data.Figure 5
Cross-validation bandwidth map.The optimal bandwidth ℎ = 0.04 is obtained from the bandwidth graph, and then the data is sharpened using the Nadaraya–Watson estimation-based data sharpening method to obtain the sharpened graph. From the sharpened data graph, we can see that the estimated red dashed line based on the Nadaraya–Watson estimation method is different from the original data, and the first and third wave peaks are lower than the original data after sharpening. Therefore, we can use the data sharpening method to reduce the model error and obtain more accurate results (Figure6).Figure 6
Data sharpening graph.The residuals of the bivariate and eight-variate data filtered with the VAR model are then examined using the nonlinear NKTN causality test. Finally, the residuals are tested with the symmetric GARCH-BEKK model and APARCH model after filtering the volatility data to obtain the unidirectional and bidirectional causality of RMB exchange rate changes. It is found that the causal relationship between the variables decreases with the filtering method, indicating that there is a causal relationship between the residuals and volatility. To reduce the error in the multivariate causality test, we use the data sharpening method, which is to obtain new data by acting on the data with a high-dimensional kernel function. In this paper, we propose the approximate test statistic QNKTN and its limiting distribution based on the research method in Diks and Wolski [21] and the data sharpening method. The nonlinear QNKTN causality test yields nonlinear causality not detected by the nonlinear NKTN causality test, which validates the feasibility of the QNKTN statistic and its limiting distribution, and illustrates that the data sharpening method enhances the performance of the multivariate causality test.The numerical simulations and empirical analyses in this paper verify the feasibility of data sharpening methods for multivariate nonlinear Granger causality tests, and the performance of nonlinear QNKTN causality tests is enhanced by data sharpening. We can use the data sharpening method to effectively reduce the bias of multivariate nonlinear Granger causality test, and we also need to further investigate the application of the data sharpening method in nonlinear Granger causality test for multidimensional data such as 3D and 4D data. For the linear Granger causality test, we compare the study of linear Granger causality with the study of nonlinear Granger causality. The bivariate and eight-variate tests of linear causality are applied to the raw data of RMB exchange rate changes using the linear Granger causality test. The linear relationship is then filtered by the VAR model on the raw data and the residuals are subjected to the linear Granger causality test to obtain the causal factors. Finally, the residuals were filtered by symmetric GARCH-BEKK model and APARCH model to examine the change in causality after filtering volatility, and the relationship and causes of exchange rate changes were studied from multiple methods and perspectives to obtain the most direct linear causality between variables.


## 3.2. Impact Evaluation Results

Since the results of such an analysis alone do not give an overall picture of the ecological coherence of each situation, standardization of the various ecological impacts is also required. The purpose of standardizing the parameter results is to better recognize the relative magnitude of each parameter result in the product system under study. This step is the process of calculating the results of the type parameter calculations by dividing them with the very quasi-values. After standardization, the ranking of the equivalent values caused by each ecological impact category of cement product foreign trade is GWP > ADP > AP > NP > POCP > HT, which indicates that the global warming effect is the largest among the ecological impacts caused by cement product foreign trade, followed by the nonrenewable resource consumption and effects. Comparing the eco-environmental impacts of import and export of cement products, the total eco-environmental impact equivalent value of an exported unit of cement products is 16.41% more than that of imported, among which ADP is 3.22% more; GWP is 23.51% more; POCP is 9.98% less; AP is 3.35% less; NP is 11.33% less; HT is 42.88% more.The relative index of ecological impact can be expressed in terms of the ratio of the number of ecological impact equivalents to the total number of ecological impact equivalents corresponding to the entire study area. According to the formula of the relative index of eco-environmental impact, the characteristic knot of the eco-environmental impact of each functional unit of cement product foreign trade can be standardized, and the results are shown in Figure7.Figure 7
Ecological and environmental impact equivalents of foreign trade in cement products.After the standardization of ecological impacts, it is necessary to determine the weight coefficients of each ecological impact, and then obtain the specific environmental impact values. The standardized ecological impact types can be theoretically summed up by unifying the scale and reference standard, and thus the overall ecological coordination can be quantitatively analyzed. Given the different importance of each ecological impact type, the relative weights of each ecological impact type should be determined. The weighted evaluation uses value-based coefficients to convert the index values of each ecological impact type and then combines the parameter results. Since there is no fixed method to determine the weighting factors because it is not very mature yet, the common methods include the expert method, hierarchical analysis, and linear regression equation method. In this paper, the combination of hierarchical analysis and expert method is used to determine the weights. The principle of the abbreviated method of hierarchical analysis is based on experimental data and expert opinion to determine the relative importance of each ecological impact type, then, with the help of matrix operations to derive the relative weight coefficients of each ecological impact type, and finally, the weighted sum to determine the total ecological impact index. Based on the comprehensive analysis of existing cement environmental compatibility evaluation reports and relevant public publications, and combined with expert opinions, the importance scales of cement production eco-environmental impact types are determined in this paper. The relative importance scale used in this paper is shown in Figure8.Figure 8
Ecological impact type desirability scale.The sum of the impact ratios of ADP and GWP both exceed 96%. This indicates that the impact on nonrenewable resource depletion and global warming is still the largest among the ecological impacts of foreign trade in cement products, followed by acidification, with little impact on photochemical ozone formation, eutrophication, and human health damage. From Figure8, it can also be concluded that the total eco-environmental impact equivalent value of exported cement products per unit function is 16.00% more than that of imported ones, including 10.31% more ADP; 23.50% more GWP; 10.16% less POCP; 3.33% less AP; 11.43% less NP; and 60.00% more HT. Due to the high solid waste recycling rate of imported cement products, not only the amount of limestone is saved, but also the raw mill output is increased, the crushing and grinding of limestone are greatly reduced, and the consumption of electricity and coal is correspondingly reduced, which makes the consumption of nonrenewable resources decrease. In addition, the reduction of limestone consumption leads to further reduction of CO generated by calcium carbonate decomposition, and thus the impact on the country is also reduced.In addition, according to the model of the AGP method, ADP corresponds to the resource consumption coefficient, and GWP, POCP, APNP, and HT corresponds to the environmental impact load. The resource consumption coefficient of imported trade is 23.626 and the environmental impact load is 24.581, accounting for 49.01% and 50.99% of the total ecological impact of imported trade, respectively; the total resource consumption coefficient of foreign trade is 49.689 and the total environmental impact load is 54.439, accounting for 47.72% and 52.28% of the total ecological impact index, respectively.


## 4. Conclusion

(1)
The scale effect and technology effect of import and export trade of Chinese cement products have negative effects on the ecological environment, while the structure effect has positive effects on the ecological environment; the trade openness of the export trade has negative effects on the ecological environment, while the import Beidetd discusses the effects of mode effect, technology effect, and trade openness on the ecological environment of foreign trade of products, and concludes that the scale effect, technology effect, and trade openness have negative effects on the ecological environment.(2)
It is concluded that the scale effect, technology effect, and trade openness harm the ecological environment, while the structural effect on the ecological environment cannot be determined because of the difference in the effect on different pollutant emissions. According to the model of AGP method, the resource consumption coefficient of export trade of Chinese cement products is 26.063 and the environmental impact load is 29.858, accounting for 46.61% and 53.39% of the total ecological impact of export trade, respectively; the resource consumption coefficient of import trade is 23.626 and the environmental impact load is 24.581, accounting for 49.01% and 50.99% of the total ecological impact of import trade, respectively.(3)
LCA can provide a more complete overview of the interaction between product life cycle and ecological environment, thus promoting a comprehensive and correct understanding of the ecological impact caused by the product life cycle. LCA can provide a more complete overview of the interaction between product life cycle and ecological environment, and thus promote a comprehensive and correct understanding of the ecological impact caused by product life cycle, and provide a judgment basis for finding ways to improve the ecological environment and for product and technology selection. In addition, LCA as a systematic method and tool overcomes the limitations and stages of traditional methods for analyzing the problems and is a very important guide for improving the overall ecological environment quality.



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*Source: 3467483-2022-07-08.xml*