4.1.1. Collinearity Test
The paper first conducts a systematic test for potential multicollinearity issues in the model to ensure the independence of the explanatory variables and enhance the robustness of the regression results. The multicollinearity test is not only an important part of the model construction process, but also assists the researcher in screening out the key explanatory variables to avoid the interference of redundant variables on the model performance, resulting in the better explanatory power and predictive ability of the model. Specifically, the multicollinearity test evaluates the degree of co-variance by calculating the variance inflation factor (VIF), which represents the ratio of the variance of the regression coefficients of the variables. The larger the value of VIF is, the more serious the problem of multicollinearity exists. Meanwhile, the inverse of VIF (i.e., tolerance) can also be used as another important indicator of covariance. When 0 < VIF < 10, it can be assumed that there is no multicollinearity between the variables; when 10 ≤ VIF < 100, it indicates the existence of strong multicollinearity; when VIF ≥ 100, it indicates that the problem of multicollinearity is very serious, which may seriously affect the credibility of the regression results.
In this paper, the core explanatory variables and control variables were analyzed by VIF in the constructed regression model. The test results are shown in
Table 2, the VIF value of each variable is less than 10, indicating that there is no significant multicollinearity problem among the indicators selected in this paper.
In summary, from a statistical point of view, the independence between the variables in this study has been fully verified. This not only reduces the risk of possible interference of multiple covariance on the regression analysis, but also lays a solid foundation for the robustness of the subsequent analysis results. At the same time, the test results further enhance the model’s ability to explain the relationship between the control factors and the primary explanatory variables, providing the credibility of the empirical test results.
4.1.3. Benchmark Regression
In order to address the possible endogeneity of individual and time effects, it was indicated that this study should use a fixed-effects model for the regression analyses. In order to further improve the robustness and credibility of the findings, this study adopted the stepwise regression method to test the hypotheses. The stepwise regression method not only ensures a more detailed examination of variable relationships but also minimizes potential bias by systematically incorporating additional control variables. This approach enhances the interpretability and reliability of the results and provides strong empirical evidence for the hypotheses.
The first column of
Table 4 represents the core explanatory variable
x (NRD) showing a statistically significant positive correlation with the dependent variable (TFPCH) at the 1% significance level without the inclusion of control variables. In the third column of
Table 4, which shows the case when all the control variables are added, NRD remains positively correlated with the index of change in TFPCH with a coefficient of 5.7269, which is significant at the 1% level of significance, indicating that all the others being constant, for every unit increase in NRD, TFPCH increases by an average of 5.7269 units. The empirical analyses show that NRD has a significant positive effect on the TFPCH, indicating that NRD has a positive effect on promoting the sustainable development of resource-based cities. This conclusion is consistent with the findings of Liu et al. [
44], Lee and He [
31], and Cheng et al. [
45] in accepting Hypothesis 1. The theoretical underpinnings of this argument can be traced as far back as Adam Smith’s book
The Wealth of Nations, where the author argued that countries rich in natural resources could utilize these resources to create wealth for the nation to become the main driver of prosperity. Building on this idea, a range of scholars have further found that natural resource-rich countries tend to have higher levels of economic performance than resource-poor countries [
46,
47]. This view affirms the potential advantages of resource wealth. Cities with high resource dependence have enabled them to accumulate a great deal of technical experience and skills in the extraction, processing, and utilization of resources. Over time, these cities have been able to gradually increase the technical efficiency of the production process, i.e., achieving more output with the current level of technology unchanged. This increase in technical efficiency directly contributes to TFPCH growth. Thus, although these cities are highly resource-dependent, they are able to compensate to some extent for the negative effects of NRD through improvements in production efficiency.
To analyze the impact of the control variables, this research first evaluates the role of GDP per capita. The regression results show that GDP per capita (PGDP) as a control variable has a significant positive effect on TFP in resource-based cities. Its regression coefficient is 0.1235 and passes the statistical test at a 1% significance level, implying that economic development plays a positive role in promoting TFP in resource cities. Economic growth is usually accompanied by the optimization of industrial structure, technological progress, and capital accumulation, which help to improve production efficiency and thus promote the sustainable development of resource cities. In addition, the authors of [
48] also suggest that rising income levels lead residents to pay more attention to quality of life and increase their awareness of environmental protection, a process that helps to promote urban TFPCH. Overall, economic development not only promotes the industrial upgrading and innovation ability of resource-based cities, but also lays a solid foundation for their qualitative or sustainable development.
However, it is noteworthy that not all the control variables exhibit a positive effect. Governance by the government (gov) as a control variable has a negative coefficient in the regression model at the 5% significance level, indicating that governance by the government is significantly and negatively related to the TFPCH. This result generally suggests that excessive local government intervention in resource-based cities and inefficiencies in fiscal expenditures are impediments to the high-quality development of these cities. Therefore, it is particularly important to reassess the sustainability of government interventions in resource-based cities. The regional economic growth in China inevitably needs to consider the far-reaching impact of local governments’ fiscal instruments on the regional economy. If there is an imbalance in governance between the government and the market, entrepreneurs may reduce their innovative behavior in favor of unproductive rent-seeking activities in order to reap excess profits through unfair means [
49]. In addition, since natural resources are relatively easy to access in resource-based cities, this resource advantage may trigger the exchange of resources for short-term economic benefits, with the sacrifice of long-term governance by the moral hazard such as bribing government officials [
50]. This poor governance model further inhibits economic transformation and high-quality development in resource-based cities.
Similarly, the control variable foreign direct investment (fdi) also exhibits a significantly negative effect at the 1% significance level, with a coefficient of −0.0135. This indicates that FDI negatively impacts TFPCH in resource-based cities. One possible explanation for this result is the “FDI crowding-out effect”, where foreign investments in resource-based cities may predominantly flow into capital-intensive or extractive industries rather than high-tech or innovation-driven sectors, thereby limiting technological spillovers and productivity gains. In addition, in China’s resource-based cities, most of the resource-related industries are dominated by state-owned enterprises (SOEs), whether they are resource development or exploration industries. A variety of reasons, such as strong government control and high policy sensitivity, have led to foreign firms facing high barriers entering these industries. Even when foreign investment enters, it is often only able to operate in the downstream or non-core areas of the supply chain, making it difficult to make a substantial contribution to technological innovation and efficiency improvement in the industry as a whole. Finally, we can see that (patent) and (struc) are not statistically significant, indicating that they do not substantially impact TFPCH in resource-based cities. This can be explained as follows. First, innovation (measured by patents) may have a lagged effect. While patents reflect the frequency of innovation activities, it takes time for these innovations to translate into productivity gains, meaning the relationship between innovation and TFPCH may not be significant in the short term. Additionally, resource-based cities are often dominated by resource-intensive industries, and the restructuring of their legacy structure is a very challenging process. Therefore, the adjustment of industrial structure and its impact on TFPCH may not be strong enough, resulting in the insignificance of this variable in the regression analysis.
This empirical finding highlights the need to reassess the governance strategies of the government to ensure that their objectives are aligned with sustainable ways. Relying on the top-down approach to governance may entrench resource dependence and slow down the transition of these cities to a more diversified and sustainable structure. In order to promote high-quality development in resource-based cities, governments need to shift from “controlling governance” to “facilitating governance”. For example, governments can build a stronger innovation base for resource-dependent cities and optimize the efficiency of resource use through field-oriented customized policies for R&D. By adjusting governance models to reduce the negative impacts of resource dependence and encouraging market-driven innovation activities, resource-dependent cities can not only escape their current development dilemmas but also achieve long-term sustainable development.
4.1.4. Heterogeneity Analysis
Based on the regression analysis as discussed above, our research will analyze the mechanism of resource dependence on the TFPCH at this second stage. For this purpose, we will carry out a heterogeneity analysis to explore in-depth the differential impacts of resource dependence on technological efficiency, technological advancement, and the stage of urban development. The heterogeneity analysis is aimed to reveal more precisely the specific path and characteristics of the resource dependence on TFPCH. The analysis is carried out in three parts. First, we will decompose TFPCH with technical efficiency and technological progress separately, in order to clarify through which part of resource dependence mainly affects the change in TFPCH. Second, based on the classification criteria of the National Sustainable Development Plan for Resource-based Cities (2013–2020), issued by the State Council, resource-based cities will be grouped according to their development stages (growth, maturity, decline, and regeneration) to analyze the differentiated roles of resource dependence at the different development stages. Specifically, the growth stage is characterized by rapid resource exploitation, with resource industries serving as the primary driver of economic development. During this phase, industrial diversification remains limited, and economic growth heavily depends on resource extraction. In the maturity stage, resource development stabilizes, and the industrial structure becomes more established. However, a high reliance on resources persists, and the need for economic transformation gradually becomes apparent. The decline stage is marked by resource depletion, leading to a slowdown in economic growth. The industrial structure remains highly specialized, lacking diversification, making economic transformation and industrial restructuring imperative. In the regeneration stage, cities actively pursue industrial upgrading and economic diversification through technological innovation, ecological restoration, and the development of emerging industries, with the objective of achieving long-term sustainable growth. This classification is based on the National Sustainable Development Plan for Resource-based Cities (2013–2020), which was introduced in 2013 with a seven-year implementation period. The plan aims to guide and support the sustainable development and transformation of China’s resource-based cities by addressing challenges related to resource dependence, economic restructuring, and environmental sustainability. Third, according to the criteria of the Macroeconomic Research Institute of the State Planning Commission, this paper will classify cities based on natural resource types (oil, coal, natural gas, minerals, nonferrous metals, and others), and explore the heterogeneous effects of different resource types on the change in TFPCH. This analysis will shed light on the role of NRD from the perspective of resource types, which fills the gap in the existing research, showing the major contribution of this paper.
Given the large diversity of production technologies among provinces and cities, it is more appropriate to use a non-parametric method to measure TFPCH. Since the imposition of a uniform production function form may lead to bias in its implications, this paper treats all our DMUs independently and uses the Malmquist index to measure and compare TFPCH. To further reveal the driving factors of TFPCH, this paper uses the Malmquist index decomposition into the index of technical efficiency change (TECH) and the index of technological progress (TECCH). These two sub-indices will be separately examined for the specific paths of the variable x’s effect on TFPCH. Based on the regression results in
Table 5, when the dependent variable is TECH, the variable
x shows a positive correlation with TECH at the 1% level of statistical significance. This suggests that
x primarily promotes the growth of TFPCH by enhancing technical efficiency. This finding suggests that the improvement in technical efficiency may stem from the improvement in resource allocation or the optimization of the management, as the path for the improvement in TFPCH. In contrast, when the dependent variable is TECCH, although the coefficient of
x is positive, it is not statistically significant. This suggests that
x has a weak effect on technological progress and fails to significantly drive technological innovation or breakthroughs. This result reveals the possible contradiction in the choice of development paths for resource-based regions; in the short term, relying on the efficient use of resources and/or managerial optimization can drive economic growth, but in the long term, insufficient technological progress may lead to insufficient development momentum for sustainable development.
To further promote productivity growth, policymakers should give priority attention to technological progress rather than simple technological efficiency. The promotion policies should focus on creating more favorable conditions for technological progress through enhanced investment in R&D and technology transfer mechanisms. Through these comprehensive initiatives, resource-based regions are expected to break away from the shackles of traditional resource dependence and achieve sustainable economic growth. In conclusion, the empirical analyses in this paper not only verify the key role of the TECH path in TFP growth but also provide important insights for resource-dependent regions to achieve high-quality sustainable development.
In order to explore the differentiated role of resource dependence on the TFPCH at different development stages, this paper classifies resource-based cities into growth, maturity, decline, and regeneration groups based on their development stages. The significance of this categorization lies in the fact that resource-based cities can be captured by their differentiated stages of development resulting from the obvious differences in development patterns and policy needs. Through categorical analysis, it can provide a basis for the development of more precise and appropriate land development policies.
From the regression results in
Table 6, there exists significant heterogeneity in the effect of resource dependence on TFPCH at different stages of development. In the growing and regenerating urbanization stage, resource dependence is positively associated with the change in TFPCH and it is significant at a 1% significance level. This suggests that resource-based cities in these two stages developed a better performing system of resource utilization and management, with higher efficiency on resource allocation and thus higher technical efficiency. As an exemplary case among the growing cities, Ordos City in Inner Mongolia is represented by its proactive resource exploitation as the core driver of economic growth. Abundant energy resources have kept its economy in a high growth mode, and the contribution of the resource industry to the land development maintained at a significant level. Ordos has also promoted R&D investment and green transformation in recent years in an attempt to further explore sustainable development, resulting in much better performance of the local economy. Regenerating cities, such as Luoyang City in Henan Province and Tangshan City in Hebei Province, have largely shifted away from their high dependence on resources toward diverse economic and social development with a focus on the technological innovation capacity. On the contrary, declining cities such as Jingdezhen City in Jiangxi Province, are facing serious challenges coming from depleting resources and lagging economic development. In contrast, mature cities, such as Datong in Shanxi, have entered a relatively stable stage of development. The growth rate of resource-dependent industry has decreased, and thus the impact of resource dependence on TFPCH is gradually weakening, resulting in the lack of statistical significance on the regression.
To summarize, China has a large number of resource-based cities with significant differences in resource endowment, different levels of economic and social development, and different intrinsic problems. Therefore, the key path to promote the high-quality development of resource cities is to tailor the policy measures to the local conditions. For cities at different stages of development, differentiated policy measures should be adopted to achieve stronger governance.
Having analyzed the impact of different stages of development (growth, maturity, decline, and regeneration) on TFPCH, we will evaluate the source of differences in the different resource types (oil, coal, natural gas, minerals, non-ferrous metals, etc.) to propose the more comprehensive role of NRD in sustainable development.
As shown in
Table 7, diverse types of resources such as oil, coal, minerals, non-ferrous metals, and other resources are all significant, with the exception of natural gas, at least at a 10% level with positive coefficients, suggesting that these resources positively affect TFPCH growth to some extent. This result shows the very insightful implications in several ways. First, resources such as oil, coal, minerals, and non-ferrous metals are often accompanied by well-established industrial chains, such as extraction, processing, smelting, and manufacturing. The exploitation of resources not only contributes directly to the resource-extracting industry, but also to the related industries. For example, coal-rich cities usually promote more complicated energy supply chains, resulting in a more enhanced TFPCH in general. Second, resource-based industries often generate considerable fiscal revenues for the local economy, which in turn support infrastructure construction and R&D investment in other related industries. Such fiscal support can promote technological progress and labor productivity, enhancing the long-term growth potential of the local economy. Finally, traditional mineral resource cities are often supported by national policies, such as special subsidies and tax incentives, to promote the efficient use of resources and the sustainable development of industries. From a comprehensive perspective, resources such as oil, coal, minerals, and non-ferrous metals have a more obvious role in promoting TFPCH, mainly due to their longer industrial chain, strong driving effect, larger financial contribution, and higher policy support. Natural gas, on the other hand, fails to show a statistically significant impact due to its relatively short industry chain, long development cycle, and imperfect market mechanism.