Abstract
Reasonably allocating the micro factor investment in the industry and trying to improve the energy efficiency are very important for the green development of industrial economy in Hebei Province, so as to the achievement of its double carbon target. This paper takes industrial energy consumption, assets and labor in Hebei Province as micro-input elements. Based on the panel data of 34 industrial industries in Hebei Province from 2005 to 2016, we identify the correlation of micro-input factors in different industries and conduct Granger causality test. The study shows that: (1) About half of the industry’s combined energy consumption is correlated with the number of employees and assets; About two-thirds of the industry’s asset workers are relevant; (2) There is a two-way causal relationship between the total energy consumption and assets of most industries and the annual average number of employees. (3) The rational allocation of capital, labor and energy consumption depends on the deepening reform of the factor market. The high energy consumption industry should actively improve and innovate the energy technology in this process to realize the coordinated promotion of energy saving and carbon reduction, and thus to promote the healthy and sustainable development of the industry steadily.
Introduction
According to the National Economic and Social Development Statistics Bulletin of Hebei Province in 2020, the total industrial added value of Hebei Province in 2020 was 1154.59 billion yuan, and has increased of 4.6% over the previous year, in which the industrial added value above the scale increase by 4.7%. At the same time, energy conservation and consumption reduction are also steadily advancing, industrial energy consumption has kept decreasing, and energy consumption per unit industrial added value of the province has decreased by 4.58%. However, despite the continuous efforts of Hebei Province to accelerate the transformation from a large industrial province to a strong industrial province, the characteristics of high economic growth, high consumption, high emission, low efficiency in Hebei Province are still very prominent, the situation of energy saving and consumption reduction is serious. Based on this, through the research on the driving factors of energy utilization efficiency and its interactive relationship, the paper helps Hebei government to find the key breakthrough to improve energy efficiency and promote industrial transformation, to form the industrial structure strategy for improving Hebei industrial energy efficiency. Realize the high-quality development of industrial industry and build Hebei into a resource-saving society with low resource consumption, less environmental pollution and good economic benefits.
At present, the domestic and international research results on industrial efficiency and its influencing factors are relatively rich, the main research methods can be divided into: Factor decomposition method, Stochastic Frontier Approach, Data Envelopment Analysis and spatial measurement methods. Factor decomposition method emphasizes energy efficiency and intensity [1]. For example, Wu [2] believes that the main factors driving industrial green transformation are energy technology reform, energy structure adjustment and environmental effects of new energy sources. The stochastic frontier production function can calculate the difference of energy efficiency, and decompose the deviation of decision-making unit from the frontier into two parts: Technical efficiency and stochastic disturbance. Wu and Li [3] took the total factor energy efficiency of Shandong province as the research object, estimated the parameters in the stochastic frontier by the Bayesian estimation method of a priori distribution. DEA has been widely used in the field of industrial efficiency research [4]. Taking the inter-provincial industrial energy efficiency of China as the research object, Xu and Li [5] use the empirical study of DEA method to show that the scale of industrial enterprises, foreign investment and technological progress have a positive impact on energy efficiency, among which foreign investment has a greater impact. Wu and Gao [6] used the DEA-Malmquist productivity index to construct an econometric model to test the relationship between energy price, TFP and energy intensity. The impact of efficiency improvement, technological progress and relative energy prices on industrial energy intensity was investigated from the perspective of industry heterogeneity [7]. He et al. [8] combine DEA with rough set theory (RS) and fuzzy artificial neural network (FANN) to classify the provincial regions according to the energy efficiency level, taking into account the non-linear and hysteresis effects between energy efficiency and influencing factors.
In addition, some scholars have discussed the influence factors of industrial efficiency through the construction of spatial model [9, 10]. Using dynamic spatial Durbin model, Han et al. [11] discussed the mechanism behind the influence of urban agglomeration economy on industrial energy efficiency. Dong et al. [12] constructed three new techno-economic correlation matrices. Spatial autoregressive combinatorial model is used to study the spillover effect of industrial integration, which confirms the spillover effect of industrial association.
To sum up, the existing literature is rich in the estimation of industrial energy efficiency and the investigation of the influencing factors, methods and emphasis are different. Some scholars pay attention to the regional differences of the influencing factors of industrial energy efficiency; Some scholars examine the channels through which the factors affecting industrial energy play a role [13]. As we all know, how to improve the efficiency of energy utilization is an urgent problem that needs to be solved in engineering science and technology circles. Especially in the period of accelerated development of industrialization and urbanization, in the face of the country’s strategic task of adjusting the structure and changing the mode, the requirements for industrial energy conservation are higher. Micro-input factors involve all aspects of energy-saving and emission reduction in key energy-consuming industries and production processes. In order to optimize the distribution of factors, improve the allocation efficiency of production factors, actively tap the growth potential, and promote the development of high quality industry, this paper pays more attention to the correlation between the factors of energy efficiency.
Correlation analysis of influencing factors of industrial energy efficiency in Hebei Province
Overview of correlation measurement methods among factors and data sources
Correlation analysis is a kind of data method to judge whether the variables are related to each other, and to judge the degree of correlation among the related factors [14, 15]. When the correlation coefficient is large, the closer the relationship between variables is, the lower the correlation coefficient is, the lower the degree of closeness is. Generally, when the correlation coefficient is less than 0.5, the correlation among variables is low. The variables were significantly correlated between 0.5–0.8; Above 0.8 is highly correlated.
The correlation analysis method is introduced to analyze the correlation between each index, and the correlation coefficient between any two indexes is solved by Eq. (1):
where,
where
The data used in this paper, energy consumption, average annual number of all employees and total assets are derived from the Economic Yearbook of Hebei Province for 2005–2016. Industrial enterprises in this paper designated SIE are all state-owned enterprises and non-state owned enterprises with annual revenue from principal business over 5 million yuan from1998 to 206, and are industrial enterprise with annual revenue from principal business over 5 million yuan from 2007 to 2010, and are industrial enterprise with annual revenue from principal business over 20 million yuan since 2011. The equation for calculating the annual average number of all employees is:
where
If there is a random process
Then for all
In the above model,
Energy, labor, and assets are the basic production factors of industry, as well as important indicators to measure the operation of industrial enterprises. Three microcosmic influencing factors of industrial energy efficiency in Hebei Province: Comprehensive energy consumption (energy), annual average number of employees (labor) and total assets (asset) were tested. From the perspective of the whole industry, the correlation coefficient between total assets and comprehensive energy consumption is 0.7813, and the results are all significant at the level of 1%. Therefore, total assets are moderately related to combined energy consumption. The test results are shown in Table 1.
Summary of correlation analysis results
In conclusion, the annual average number of all employees in about half of the industries is correlated with the integrated energy consumption, and the total assets is correlated with the integrated energy consumption; About two-thirds of the total assets in the industry are correlated with the annual average number of all employees.
Economic and social development depends on energy, but energy is limited, which requires guiding high-energy-consuming enterprises to improve technology, strengthen management, and improve energy efficiency. Whether the relationship between industrial energy efficiency and other factors is scientific and reasonable is directly related to the effectiveness of energy conservation and carbon reduction in key industries. Therefore, continuous optimization and dynamic adjustment are required.
Summary of Granger causality test method
Granger causality is defined as “the variance of the best least squares prediction that relies on all information at some point in the past” [16]. In the case of time series, the Granger causality between the two variables X and Y can be defined as “if the prediction effect of the variable Y is better than the prediction effect of only the past information of Y under the condition that the past information of the variables X and Y is included, then the variable X is the Granger cause of the variable Y” According to the definition of Granger causality, judge whether there is Granger causality between X and Y. Granger causality expresses statistical correlation, which is the continuity of phenomena in the sense of time.
The Granger causality test for the two variables X and Y requires the construction of a regression equation containing the hysteresis terms (sum) of X and Y, as shown in Eqs (7) and (8).
where,
In this section, Granger causality test was conducted among three microcosmic factors of total factor productivity (TFP) of industrial energy in Hebei province, comprehensive energy consumption (energy), annual average number of employees (labor) and total assets (asset). In order to ensure the stability of each variable and prevent the phenomenon of pseudo-regression, the stability of each variable is tested first, and the test results are shown in attached Table S1. According to the test results in Appendix 1, Granger causality test is conducted for stable variables in various industries. See Appendix 2 for the test results. According to the First and Second Schedules, the causal relationship between the comprehensive energy consumption of each industry, the total assets and the annual average number of employees is summarized as shown in Table 2.
Summary of causality of energy consumption, labor and asset level in each industry
Summary of causality of energy consumption, labor and asset level in each industry
In conclusion, there is a two-way causal relationship between the total comprehensive energy consumption and assets of most industries and the annual average number of all employees, there is a one-way causal relationship between three variables of a small number of industries, and there is no causal relationship between three variables of a very small number of industries.
Ferrous metal smelting and rolling processing industry, non-metallic mineral product industry, electricity and heat production and supply industry, coal mining and washing industry, chemical raw material and chemical product manufacturing industry, petroleum processing coking and nuclear fuel processing industry are the six major energy-intensive industries in Hebei Province. In 2015, the energy consumption per unit of industrial added value in Hebei province dropped by 24% compared with 2010, and the contribution rate of the six major energy-consuming industries to the province’s industrial growth has dropped from 33.7% in 2010 to 29.4% in 2015.
There is a causal relationship between the total assets of these three industries and the comprehensive energy consumption (non-metallic mineral product industry, petroleum processing coking and nuclear fuel processing industry and ferrous metal smelting and rolling processing industry). It is worth emphasizing that the energy consumption of the output value of the above six industries all showed a downward trend during the study period. For instance, the energy consumption per unit GDP of coal mining and washing industry dropped from 2.87 in 2005 to 1.2 in 2016. The same indicator of petroleum processing, coking and nuclear fuel processing industries, chemical raw materials and chemical products manufacturing, non-metallic mineral products industry fall back more than 1.5 times. It may related to the province’s strict implementation of energy consumption limits, special pollutant discharge limits, differential electricity price and water price policies, and the establishment of special funds for eliminating outdated production capacity.
Among the 34 sub-sectors of Hebei’s industry, coal mining, chemical materials and ferrous metal smelting and rolling processing industries such as steel, petrochemical, and chemical industries have significantly higher energy consumption per unit of GDP than other industries. Under the goal of carbon neutrality, those industry in Hebei Province needs to consolidate the results of capacity reduction and resolutely curb the blind development of resource-based heavy chemical industries such as the “High pollution and high energy consumption” projects [17]. Under the policy constraints of emission reduction, the steel, petrochemical, and chemical industries have huge potential to implement industrial low-carbon transformations and coordinate to reduce energy consumption, so as to avoid excessive consumption and expansion of assets to energy inputs. Relevant industries should pay attention to the energy-saving efficiency of asset investment projects, speed up the renewal and iteration of production equipment, and improve the energy efficiency of equipment.
Nowadays, the development of various industries in Hebei Province, especially the development of high-tech manufacturing, is increasingly dependent on innovation. This requires high-quality labor to cooperate with green technology research and development projects invested by enterprises to strengthen the main position of enterprise innovation, thereby accelerating the promotion of green upgrading of manufacturing.
(1) About half of the combined energy consumption in industry is related to the number of employees and assets; About two-thirds of the industry’s assets are correlated with the number of employees. Most of the industries which are highly correlated with the integrated energy consumption are light industries in the manufacturing industry classification, showing the demand for labor in the energy consumption process of some industries. In contrast, manufacturing and processing industries such as metals and non-metals show an irrelevance between assets and labor, suggesting that labor mobility among these industries is not sensitive to asset movements.
(2) The total energy consumption and assets of most industries are related to the average annual number of employees. The energy consumption of metal smelting and processing has a significant Granger causal relationship with the assets. Besides, the energy consumption of ferrous metal mining and dressing industry, non-metallic mining and dressing industry, non-ferrous metal smelting and rolling processing industry are all Granger causes of assets. Especially the ferrous metal smelting and rolling processing industry represented by steel products has the same feature, which shows that the traditional heavy industry growth depends on the short board of energy consumption and restricts the other investment behavior of the assets.
(3) Rational allocation of assets, labor force and energy consumption are important component factors to promote the growth of industrial green economy in China. In the future, the green development of China’s industry can not be separated from the steady improvement of energy efficiency, in which the changes of the interrelation of the traditional investment elements on the road of industrial upgrading should be consistent with the requirements of green development and reduction of energy consumption in the development plan of the period of the “14th Five-Year Plan” Enterprises in the energy-intensive industries have the motivation to pay attention to the technological investment in energy conservation, emission reduction and clean technology research, constituting a good development pattern with reasonable allocation of input elements.
Footnotes
Acknowledgments
The authors gratefully appreciate the reviewers for their constructive comments and suggestions. The authors declare no conflict of interest.
Funding
This research was funded by (1) The project of the State Grid Hebei Electric Power Co., Ltd. The topic is “Research on New Power System Development Path”. (2) The American Energy Foundation: “Research on Low-Carbon Consumption Models and Low-Carbon Society Construction in the Context of Carbon Neutrality”.
Appendix A
The Schedule 1 for this paper is shown in Appendix word.
