1. Introduction
Reducing carbon emissions has become a top priority for many nations due to the state of the environment, and the development of “carbon neutral” awareness is accelerating globally. The accomplishment of China’s “dual carbon” objective is significant on a worldwide scale and presents new opportunities and challenges for the growth of China’s economic structure. China’s environmental quality ranks 120th out of 180 countries and regions in the world with major ecological and environmental issues, according to the 2020 Global Environmental Performance Index study jointly released by Yale University and other institutions [
1]. At the same time, figures show that, in 2019, China was responsible for 27.92% of the world’s carbon emissions. The problem of carbon emissions is very prominent, and excessive carbon emissions will cause serious harm to the environment [
2]. The development of green technology innovation is an important factor to promote the transformation of an economic development mode [
3] and also an important means to achieve sustainable development [
4]. To achieve the “double carbon” objective in the face of difficult environmental issues, it is imperative to speed up the promotion of green transformation in the new era.
According to data released by the China Building Energy Efficiency Association, the total carbon emission from the whole process of construction is more than half of the total carbon emission in China [
5], which seriously hinders the green development of the economy. The construction industry, a pillar of the national economy, is crucial to raising the level of the country’s economy. However, with the rapid development of the construction industry, problems such as large resource consumption and extensive construction methods in the construction industry have become increasingly prominent [
6], which will also cause irreversible damage to resources and the environment such as carbon dioxide emission [
7]. Construction companies urgently need to follow the path of green and low-carbon development due to serious environmental issues, the need to reduce carbon emissions, and the need to actively explore the new model of low-carbon development, which is of great significance for controlling total carbon emissions, realizing green development, and guiding and promoting the conclusion of the Paris Agreement [
8]. To achieve the decoupling of green economic development from resource consumption and environmental pollution, green technology innovation seeks to maximize economic, ecological, and social benefits with minimal cost and pollution [
9]. When conducting innovation activities, consideration should be given to the efficiency of green technology innovation in order to realize the sustainable and high-quality development of the construction sector [
10].
This study examined the spatial and temporal differential characteristics and key influencing elements of green technology innovation efficiency in the construction industry, using the construction industry as the research topic. In order to further share knowledge and make policy recommendations for enhancing the efficiency of green technology innovation in the construction sector, this paper used the following framework:
Section 2 outlines the study’s theoretical basis;
Section 3 introduces the research area, research methods, and selection and measuring of variables;
Section 4 summarizes the research findings;
Section 5 discusses the research results and draws conclusions.
2. Theoretical Review
Joseph A. Schumpeter (1991) was the first to put forward the theory of technological innovation. Technological innovation can boost productivity, deliver competitive advantages and good economic benefits to society, an industry, or an organization, and alleviate numerous difficulties that humans encounter. The traditional model of technological innovation, however, is overly simplistic, and rapid economic growth results in a shortage of natural resources and environmental pollution, severely impeding the path to sustainable development and impeding the transition to a greener form of economic development. Green and sustainable development is a crucial tool for advancing ecological civilization and superior economic growth [
11,
12,
13,
14]. Green technology innovation was proposed in 1960 to efficiently address the difficult environmental pollution issues that Western nations were facing and to offer technical help [
15]. Green technology was formally defined by Braun and Wield [
16] in 1994, who argued that it was important for improving environmental quality [
17]. Most academics agree that green technology innovation is one of the key steps to take into account both the ecological environment and a low-carbon economy in order to address the internal conflict between economic expansion and environmental pollution [
18,
19,
20]. Additionally, the advancement of green technology has emerged as a crucial element in advancing sustainable development [
21,
22]. Under the background of sustainable development, the relevant policies for green technology innovation have been continuously introduced and implemented, promoting the development of green technology innovation. Green technology innovation is distinct to traditional technology innovation, as it is theoretically based on ecology, information science, sociology, current management, etc. [
23]. It pays attention to saving circulation, efficient utilization, and reducing pollution, and plays an important role in realizing sustainable development [
24]. Research on green technological innovation is currently focused primarily on connotation, assessment, and influencing variables both domestically and internationally.
Various scholars have different meanings for the meaning of “green technology innovation efficiency” in their research. Pedro (2004) [
25], Werf (2003) [
26], and others consider “green technology innovation” as technological innovation that takes full account of environmental factors on top of traditional innovation. Hellstm (2007) [
27] believed that “green technology innovation” should consider reducing the impact on the environment while meeting product innovation. Manral (2018) [
28] and Yudietal et al. (2019) [
29] defined the term “green technology innovation” as a process that starts with the goals of preserving the environment, conserving energy, and reducing emissions as the premise and achieves financial gain. Though there is not yet a common definition of “green technology innovation” in academia, it typically refers to novel technologies that can enhance environmental performance [
30]. Acemoglu (2012) [
21] and Wang et al. (2021) [
31] believed that “green technology innovation” is a new technology that can inhibit energy consumption while reducing pollutant emissions, improving environmental quality, and promoting green economic development [
32] and is widely recognized by the general public.
The evaluation of green technology innovation focuses on its efficiency, primarily through the development of indicators, stochastic frontier analysis (SFA), and data envelopment analysis (DEA). Sun et al. (2017) [
33] applied the entropy weighting method in order to assess green technology innovation from the standpoint of its ecological and economic performance. Li et al. (2022) [
34] created a system health evaluation index system to assess the state of green technology innovation. SFA is not suited to complicated systems, with many inputs and multiple outputs since it is a typical parametric analytic technique with little room for error in function selection and parameter configuration [
35]. The data envelopment analysis method can overcome the defects caused by the ratio method and index system calculation method. Early data envelopment analysis techniques, such as BCC (Banker-Charnes-Cooper) and CCR (Charnes-Cooper-Rhodes), were used to gauge how well green technology was able to innovate. Lin et al. (2018) [
36] used the ideal window width DEA window analysis method to assess the efficiency of green technology innovation. When the results were compared, it was thought that the obtained results were more realistic than the calculation results of the conventional DEA model. The measurement results are not accurate, because the conventional model overlooks the relaxation of variables [
37]. In 2001, Tone constructed a DEA-SBM model considering the relaxation of output and input factors [
38]. The DEA-SBM model was employed by Feng et al. (2013) [
39] to assess the effectiveness of green technology innovation. As research has continued to advance, many academics have taken unwanted output into account when calculating the efficiency of green technology innovation. They have also developed the super-efficiency SBM model [
40,
41] that incorporates unwanted output in order to increase the precision of efficiency assessment.
The government, the market, the general public, and the industry itself are the primary players in the study of the factors that affect the development of green technologies. The research perspectives of green technology innovation range from macro to micro, mainly focusing on regional, industrial, and enterprise levels [
42]. With different perspectives and methods, abundant research results have been obtained on the influencing factors of green technology innovation [
43]. Behera et al. (2022) [
44] used the mixed mean group, random effect, generalized mixed models, and gaussian mixture model models to analyze Organization for Economic Co-operation and Development (OECD) countries. They felt that effective environmental regulation and foreign direct investment inflow might stimulate the development of green technology. Zhang (2022) [
37] built a spatial econometric model to examine the influencing variables and came to the conclusion that environmental regulation, government support, educational attainment, and industry scale all played an important role in fostering the efficiency of green technology innovation. Li (2022) [
45] used microfirms as the research subject and employed evolutionary game theory to support the contention that manufacturing companies can be encouraged to promote green technology innovation through subsidies and fair environmental legislation. Green technology innovation efficiency is a typical indicator that has both economic and ecological qualities [
37], and it is influenced by a wide range of variables such as environmental regulation [
46,
47,
48], government subsidies [
49], economic development level [
50], foreign direct investment [
43], education level [
51], industrial scale [
52], and other aspects factors.
As mentioned above, first of all, the design of an assessment system that takes into account input, output, and undesirable output is the main method of the current measurement of the efficiency of green technology innovation. Secondly, when choosing research methodologies for green technology innovation, multiple linear regression, spatial econometric models, evolutionary games, and other techniques are used. However, only linear influence is taken into account when studying the influencing factors of green technology innovation. Finally, existing research perspectives mostly focus on manufacturing, high-tech industries, and industry. Green technology innovation in the construction business is very important, because it has a reputation for being high-consumption, high-pollution, and one of the most carbon-generating industries in China. As a result, this study examines the efficiency of green technology innovation and the factors that drive it, using the construction sector as its focus. The super-efficiency model is used in this study to quantify the efficiency value by combining the methods of econometrics, geography, and physics. Furthermore, tools such as the gravitational model and geographic detector are brought into the field of green technology innovation in the construction industry to evaluate and affect elements of green technology innovation efficiency. This paper delves into green technology innovation in the construction industry, expanding and enriching the relevant content and helping to foster the coordinated development of the regional economy and regional environment. It also provides a theoretical basis for the development of targeted and regionally differentiated countermeasures for the efficiency of green technology innovation in the construction industry.
5. Discussion and Conclusions
5.1. Research Conclusions
The Chengdu–Chongqing urban agglomeration is a crucial growth pole for developing high-quality economic development in western China. This research assessed the green technology innovation efficiency of the construction sector in each city using data over the period of 16 cities in the Chengdu–Chongqing urban agglomeration from 2011 to 2019. Using a gravity model and a geographic detector, the geographical and temporal development characteristics of green technology innovation efficiency in the construction sector were explored. At the same time, the pertinent driving factors were identified, and the extent to which each driving element affects the efficiency of green technology innovation in the construction sector was explored for both single-factor and double-factor analyses. The ensuing conclusions were reached: (1) Within the Chengdu–Chongqing urban agglomeration, there are considerable regional variations in the efficiency of green technology innovation in the construction industry, and the overall trend is upward. (2) The research area exhibits spatially heterogeneous characteristics in terms of the efficiency of green technology innovation in the construction industry. Additionally, it demonstrates the tendency whereby the area with high efficiency levels gradually spreads to the surrounding areas with lower efficiency levels, and the area with low efficiency levels gradually decreases in scope. (3) The Chengdu–Chongqing urban agglomeration’s geographical spillover impact is undoubtedly constrained by distance. Additionally, the western region’s spatial spillover impact is superior to that of Chongqing’s eastern region. The western portion of the Chengdu–Chongqing urban agglomeration has a better spatial spillover impact than the eastern portion, which is represented by Chongqing. Moreover, the spatial spillover effect is significantly limited by distance. (4) Environmental regulation, the level of economic development, public environmental concern, the level of urbanization, and foreign direct investment, as the dominant factors of green technology innovation efficiency in the construction industry, and the industry’s scale as a potential factor, all have significant effects on the efficiency of green technology innovation in the construction industry. (5) In comparison to the single component, the interaction between the leading factor and the potential factor has a greater influence on the regional and temporal differentiation of green technology innovation efficiency in the construction sector.
5.2. Theoretical Contribution
This paper’s theoretical contribution, as compared to previous studies, focuses primarily on three areas:
Firstly, prior to measuring the efficiency of green technology innovation in the research area’s construction industry, the undesirable output is fully taken into account. It is discovered that the research area’s overall innovation efficiency in green technology is notably different and exhibits an upward trend. This confirms the opinion of Qian et al. (2022) [
74] that there is an imbalance in green technology innovation in inland areas and that there are obvious differences between regions. Additionally, it was discovered that places distant from the central cities were more likely to have severe solidification and ultra-low efficiency, which was in line with the findings of Xu et al. (2020) [
75]. Based on these findings, this study investigates and analyzes the characteristics of the green technology innovation efficiency of the construction sector in the study area over time and space, as well as further examining the variations between cities and the degree of spatial connectivity.
Secondly, green technology innovation in the construction sector has had an optimistic spillover effect in the study area, gradually transferring from the high-efficiency-level to the neighboring low-efficiency-level areas, and the low-efficiency-level area’s scope gradually exhibiting a trend of narrowing. The findings of Hu et al. (2022) [
76], Wang et al. (2022) [
77], and Zhao et al. (2021) [
78] are in agreement with this finding. They believe that high-efficiency areas have radiation effects on low-efficiency areas and narrow the gap between cities. In order to intuitively reveal the spillover effect between different spatial units, this paper introduces the gravity model and utilizes the spatial spillover network structure diagram. As a result, the research findings on the efficiency of green technology innovation in the construction industry are further enhanced.
Thirdly, this research analyzes the factors that affect the efficiency of green technology innovation in the construction sector. The results are consistent with those of Zhao et al. (2022) [
72], Li et al. (2022) [
45], and Stucki et al. (2018) [
79] and indicate that environmental regulation and economic development levels have a significant impact on green technology innovation efficiency in the sector. According to Porter’s theory, environmental regulation, to some extent, has a favorable effect on the development of green technology [
80]. High economic development locations typically have enough funding for green technology innovation activities, which can significantly encourage the improvement of green technology innovation efficiency. Existing studies consider the influencing factors to be thin and do not include multiple influencing factors in the same space for interaction impact analysis. In order to make up for these deficiencies, based on the characteristics of geographic detectors, factors of multicollinearity can be included in the same framework system for discussion. This paper expands the influencing factor system of green technology innovation efficiency in the construction industry and enriches the research findings by taking into account and examining the driving role of related influencing factors from the three aspects of the construction industry’s resource endowment, social economy, and environmental awareness.
5.3. Management Inspiration
The Chengdu–Chongqing City cluster is situated at the intersection of the “Belt and Road” and the Yangtze River Economic Belt, which has considerable regional advantages and serves as an essential platform for the development of the western province. With the continuous promotion of the “double carbon” policy, the construction industry is in urgent need of green and low-carbon transformation. Therefore, the following suggestions are put forward:
Firstly, develop differentiated environmental regulation policies to enhance the institutional environment for the development of green technology innovation. The Chengdu–Chongqing region’s construction industry’s use of green technology innovation is best explained by environmental regulation, which has the strongest overall impact. Increase government involvement, bolster the administration’s commitment to environmental protection, develop local conditions-specific environmental regulation laws, enhance the relevance and efficiency of environmental regulation, and facilitate the balanced development of green technology innovation efficiency.
Secondly, focus on bringing in top-notch foreign funding and promoting the advancement of green technology innovation in the construction industry. The spillover impact of technology, funding, resources, and knowledge delivered by foreign direct investment is fully utilized through the infusion of high-quality foreign investment by the government. This is a significant technique to increase the efficiency of green technology innovation in the research domain and is conducive to accelerating the transition of green technology innovation accomplishments in the construction sector.
Thirdly, encourage the public’s excitement about environmental issues and fully utilize the public’s oversight role. Develop policies to support and encourage public participation in environmental governance while continuously improving and standardizing the format of letters and media reports. This supports modernizing and scientifically validating environmental governance, ensures the timely and efficient implementation of public supervision and management, and is a crucial building block for attaining green, sustainable, and healthy development in the construction industry.
Finally, strengthen coordinated development among regions to narrow the imbalance. An efficient method of coordinating and promoting the growth of green technology innovation in the construction sector in each prefecture-level city in the Chengdu–Chongqing region is to improve the level of technical openness among cities. Give large cities such as Chengdu and Chongqing their due as “leading goose”, radiate these cities’ advantages in cutting-edge technology and resources to neighboring cities with low rates of green technology innovation, and encourage the integration and sustainable growth of the construction sector in this area.
5.4. Limitations and Deficiencies
In this study, the efficiency of green technology innovation in the construction sector is evaluated. The gravity model and geographic detector are used to investigate the characteristics of the spatial and temporal evolution of efficiency and its affecting elements. It expands and enriches the research theory of green technology innovation in the construction industry and helps to promote the green and low-carbon transformation of the construction industry. This study may have several shortcomings, which should be addressed and resolved in further studies. First of all, only the Chengdu–Chongqing urban agglomeration in China is used as the research region for this work, which focuses on the efficiency and impact variables of green technology innovation in the construction industry of 16 of those cities. However, there might be regional differences in the construction industry’s use of green technology innovation in various metropolitan agglomerations. In the future, a comparison study of typical regions such as the Beijing-Tianjin-Hebei urban agglomeration and the Yangtze River Delta urban agglomeration will be necessary. Explore in further detail the regulations for green technology innovation in the construction industry in various urban agglomerations. Secondly, the research object is not sufficiently detailed. The construction industry of each city in the region is the research object of this paper, and the research scope is broad. It can be refined further in future research, and the city can be refined further for each construction enterprise or county for more in-depth research. Last but not least, this essay primarily focuses on the effects of resource abundance, social economics, and environmental consciousness in light of the influencing variables of green technology innovation and efficiency in the construction industry. It might also be impacted by factors such as the energy consumption structure, ancillary industries, and management levels, among others, which will require more investigation and in-depth debate in the future.