1. Introduction and Literature Review
Following the implementation of economic reforms and liberalization, China’s economy has seen significant advancements. China’s gross domestic product (GDP) increased by an astounding 14.08% per year over 45 years, from CNY 367.87 billion to CNY 121 trillion between 1978 and 2022. In this context, using blockchain, artificial intelligence (AI), massive data sets, and other innovations in the financial sector, China’s financial industry is entering an era of digital transformation. A significant development in China’s economy has been the rise of digital finance, which was officially recognized in September 2016 with the release of the G20 High-Level Guidelines for Digital Financial Inclusion. Distinguished from “e-finance” and “Internet finance”, the prevailing perception of digital finance is that it is a brand-new category of economic services that combines traditional financial services with massive data sets, AI, the wireless Internet, and additional digital innovations [
1]. China’s digital finance index rose 26.9% each year from 2011 to 2021 (
http://www.199it.com/archives/1489063.html (6 September 2022)), and its fast growth is crucial to economic change and development [
2,
3,
4,
5,
6], technological innovation [
7] and industrial upgrading [
8,
9], and recognizing the city’s upward trajectory [
10]. Numerous academic studies demonstrate how the growth in electronic financing can enhance the effectiveness of urban green innovation [
11], curb carbon emissions [
12,
13,
14], empower urban green economic growth [
5,
15], and assist with urban environmental improvement [
16] and high-quality economic development [
17].
As the urbanization construction process continues to advance, the demand for urban built-up land area in China shows a rapid upward trend. The city population of China is expected to grow by 23.6 thousand km
2 between 2010 and 2022, reaching 63.7 thousand km
2. Furthermore, all cities in the country have over 75% of their urban property efficiency categorized as medium-low [
18]. The “three highs” of high energy consumption, pollution, and emissions are driving the fast increase in urban building land area and inefficient use, which threatens land carbon sequestration and sustainable use [
19]. It contradicts the principle of sustainable development in China. The emergence of ecological civilization and the advancement of urban sustainability in China is strongly dependent on the efficient, ethical, and ecologically responsible use of the nation’s limited supply of urban areas.
As a new type of land utilization combining land elements and green development concept, for urban land utilization for green spaces, the main goal is to achieve optimal use of urban space via efficient economic growth, while prioritizing intensity, environmental friendliness, and long-term sustainability [
20,
21]. In an effort to construct an assessment index system, academics started making efforts based on the basic connotations, which at first only considered inputs and expected outcomes for the analysis and evaluation of city land use’s financial sustainability [
22,
23]. Subsequently, scholars have increasingly focused on the importance of non-desired outputs in economic activities, guided by the concepts of green, low-carbon, and sustainable development. They argue that true efficiency in urban land utilization can only be achieved by considering the green utilization efficiency while accounting for non-desired outputs [
24]. Therefore, some scholars include industrial “three wastes” pollution elements into non-desired outputs on the basis of desired outputs [
25], and some experts see urban population as an undesirable outcome while developing an urban land green use efficiency analysis rating method [
26]. Following consideration of the undesirable result in the measurement process, the mainstream method has changed from the DEA model to the Super-SBM model [
27,
28]. Regarding the impact of certain data components on urban land use, several researchers have already carried out initial investigations and determined that the digital economy may improve the effectiveness of environmentally friendly green land use [
29].
To increase the effectiveness of long-term urban land utilization, technical guidance is essential. Green technical innovation, distinct from general technological innovation, places more emphasis on environmental advantages. It provides an essential technological basis for the building of a sustainable society and accelerates the adoption of a green growth and transition pattern [
30]. Innovation in environmentally friendly innovations is hampered by the high cost of financing, the presence of high risk and uncertainty, and the demanding needs for innovation. Consequently, securing conventional financial assistance for green technology innovation financing becomes challenging [
31]. In this case, digital finance, with its advantages of universality and convenience, has injected new vitality into driving green technological innovation. Additionally, experts in related studies often hold the view that digital finance has the potential to facilitate the development of environmentally friendly technology innovation [
32,
33,
34,
35]. Thus, may the effective and sustainable usage of metropolitan areas be indirectly affected by the advances in ecological technology brought about by the increase in electronic financing?
In summary, urban area green usage efficiency measuring techniques, concept formulation, and other factors have yielded important and relevant study outputs for scholars both locally and globally, but there are also the following shortcomings: 1. The majority of previous studies on how the digital sector affects the efficiency of renewable land use in cities have focused on testing novel initiatives, with no literature investigating the specific mechanisms via which digital finance affects urban land green utilization efficiency; 2. Studies on the green usage potential of cities are scarce, especially when renewable energy innovation is the underlying process. This study incorporates findings from prior studies in light of China’s transition towards a green economy and the rapid growth of digital economics. It views industrial “three wastes” and labor, capital, and land as energy inputs; it views economic, social, and environmental outputs as undesirable; and it views energy inputs as inputs. The research thoroughly evaluates the effectiveness of urban land use, with an emphasis on green land use, via the Super-SBM model. The study examines panel data from 281 Chinese cities between 2010 and 2020. The analysis intends to provide practical recommendations for sustainable use of land resources, sustainable city development and the establishment of financial policies using the fixed impact and interactive outcome concept to promote the growth of the green economy.
3. Study Design
3.1. Description of Variables and Data
The study presented here analyzes 281 Chinese cities as its subject. In addition, considering that although digital finance budded in the 1990s, rapid development started late, this paper selects 2010–2020 as the research time period, and some of the missing data are made up by the linear interpolation method.
- (1)
Described Factors
Urban Land Green Utilization Efficiency (ULGUE): this study constructs an evaluation index system using resource inputs, intended outputs, and non-desired outcomes as the primary indicators [
18,
19,
20], and the data are all from the China Urban Statistical Yearbook and China Statistical Yearbook of past years. The details are shown in
Table 1.
The majority of the current research uses the farthest distance model to the frontier (SBM) as a means of quantifying efficiency; because the SBM model measures the value between 0 and 1, there will be a series of problems in the subsequent econometric analysis process, thus affecting the precision of the experimental results. The current study uses various dimensions, such as desired and non-desired outputs, to address the drawbacks of the SBM model, and the precise green consumption efficacy of urban plots and structures was measured using the Super-SBM model, and the specific model formulas are as follows:
There are decision unit s to be evaluated for efficiency, denoted by ; each decision cell has inputs and outputs. is the efficiency value of the model, denotes the input variables of the model, denotes the model’s desired output variable, indicates the non-expected output variables, is the decision making units, and the slack variables are represented by , , and , where a value exceeding 0 means that there is room for optimization of the efficiency value. In this paper, MaxDEA8.17 is used to calculate the urban land green use efficiency index using the current frontier, non-oriented, and super-efficiency model.
- (2)
Key explaining variables
Digital finance (df). Three factors constitute the electronic financial indices: the rate of electronic records, cover breadth, and extent of usage. It is frequently employed in modern research and offers a thorough and impartial review of the overall state of advancement in financial technology. The “Peking University Digital Inclusive Finance Index (2011–2020)” was used as a stand-in for the primary explanatory variables in this study. To ensure the correctness of the regression results, the data are uniformly compressed by a factor of 100 for processing, and linear interpolation is used to deal with inaccurate data.
- (3)
Mechanism variables
Green technological innovation (Gin): Existing literature often uses R&D investment or the number of patents to reflect the technological innovation capacity of cities. China’s official statistics already have relevant data specifically for “green” achievements. In this paper, we use the original data of green patents obtained by prefecture-level cities to characterize the level of green technological innovation in cities, and at the same time, we shrink the data by 1000 times. The data come from the CNRDS database [
46].
- (4)
Moderating variables
- (1)
Environmental regulation (Er): The existing literature on environmental regulation alternative indicators for prefecture-level cities mostly uses pollutant removal rate characterization. Considering the correlation with land elements, this research use the complete utilization rate of industrial solid waste as a measure to assess the level of stringency in environmental regulation.
- (2)
Advanced industrial structure (Ais): The index of advanced industrial structure can specifically reflect the state of development of the three major industries in different regions as well as the distribution results. In the index is a positive indicator, that is, as the value increases, it proves that the degree of optimization and development of industrial structure increases significantly. This article examines the correlation between the share of the three main industries and several other factors; the Tel index is used to calculate the index of advanced industrial structure.
- (5)
Control variables
The following control variables are selected in this paper: (1) the degree of openness to the outside world (Fdi), for which the amount of foreign investment used in the current year is taken as a logarithmic characterization; (2) urban infrastructure (Utf), characterized by the road area per capita; (3) city size (LnDop), using population density to take a logarithmic view to reflect the city size; (4) the degree of government intervention (Gov), defined by the ratio of government public spending to GDP; (5) market activity (Market), defined by the logarithm of aggregate sales of consumer goods; and (6) urban education level (Edu), which is the ratio of the number of university students to the total resident population.
3.2. Modeling
- (1)
Baseline linear model
To evaluate Hypothesis H1, the baseline linear model that follows is developed in the current study:
In the above model, index “ denotes the city, index “ is the time, and represents the time of the city’s land green use efficiency in the year’s land green utilization efficiency, represents the city’s digital financial development index in the year, represents a series of control variables, , and represent individual and time fixed effects in the model, respectively, and are randomized disturbance terms.
In order to further verify the environmental regulation and the industrial structure advanced adjustment effect, this study presents the incorporation of an interaction term into the benchmark model. The particular model is outlined as follows:
In the above model, represents cities in that year, the moderating variables represent environmental regulation and industrial structure advancement, respectively. represents the city’s and the year’s modifying factors and electronic financial association term, and the other variables’ interpretations align with the baseline regression model.
- (2)
Mechanism testing
Based on the prior theoretical study, the environmental breakthrough mediated effect concept is built for studying the potential impact of online financing upon the efficient execution of urban land for sustainable objectives. The specific design is the one shown below:
In the above model, represents city’s green technology innovation in the year, and the rest of the variable meanings are consistent with the benchmark regression model.