4.1. Descriptive Statistics
To gain a comprehensive understanding of the sample distribution and identify potential outliers that may affect the regression results, it was necessary to calculate the descriptive statistics for the variables utilized in this study. This included listing the sample size, mean, variance, minimum, and maximum values separately. Analyzing these data measurements enabled us to draw relevant conclusions regarding the research findings (refer to
Table 3).
Table 3 presents a wide range of variable values, indicating the influence of various factors, such as the degree of agricultural mechanization and rural human capital, on the development and optimization of the agricultural industrial structure. The agricultural industry upgrading index ranged from a minimum of 0.622 to a maximum of 2.455, highlighting the variation in the level of agricultural upgrading across regions. Similarly, the maximum and minimum values of green financing were 0.578 and 0.093, respectively, highlighting the diversity in the implementation of green financing initiatives. Furthermore, significant differences were observed in other variables, underscoring the existing imbalance in the promotion of agricultural industrial structure optimization across different regions in China. These findings emphasize the importance and relevance of the subsequent research conducted in this paper.
4.2. VIF Test
If a variable can be expressed linearly by other variables, it indicates that the model has some multicollinearity problems. Since advanced green financing development and agricultural industrial structure were calculated by building an index system, more variables were adopted, and more control variables were selected. Therefore, this study needed to use the variance inflation factor to test the multicollinearity of the data (
Table 4).
The mean variance inflation factor of the variables was 1.22, and the variance inflation factor of the remaining variables was also significantly less than 10, with the maximum variance inflation factor of the five variables being 1.41, which is much less than 10. This demonstrated that there was no multicollinearity, and that the model could be used for a regression analysis.
4.4. Cointegration Test
The cointegration test helped us determine if there was a long-term relationship between variables. The Westerlund cointegration and Pedroni cointegration tests were also employed in this study.
H0: No cointegration in the Westerlund test. H1: Some panels are cointegrated.
The
p value of the variance ratio statistics reported in
Table 6 was 0.0000, and their corresponding
p values were all less than 0.01. Therefore, the original hypothesis “no cointegration relationship exists” could be strongly rejected at the 1% level, and we believed that there was a cointegration relationship between variables.
In the Pedroni test, the hypotheses were: H
0: no cointegration; H
1: all panels are cointegrated. Three different test statistics are reported in
Table 7, and their corresponding
p-values were all less than 0.01.
4.5. Results of Regression
This section of the study verifies the impact of green finance on the optimization of the agricultural industrial structure through a comprehensive analysis. Several tests, including the VIF test, unit-root test, and cointegration test, were conducted on the model to examine the relationship between the variables. The results presented in
Table 7, incorporating fixed region effects, indicated that the development of green finance had a significant positive influence on the improvement of the agricultural industrial structure’s optimization level.
However, it is crucial to consider potential endogeneity issues arising from the causal relationship between variables. To ensure the reliability of the results, the Hausman test was employed to compare the fixed-effects and random-effects models. The Hausman test statistics and associated p-values were utilized to determine the most suitable regression model.
The statistical indicators and
p-values from the Hausman test guided the selection of the specific regression model. The null hypothesis (H
0) assumes that the random-effects model is the ideal choice, regardless of the accuracy of the initial hypothesis. Conversely, if the null hypothesis is proven incorrect, the fixed-effects model is deemed more reliable. In this study, the findings of the Hausman test strongly rejected the null hypothesis at a 99% confidence level (Prob > Chi2 = 0.0000, as shown in
Table 8). Hence, the fixed-effects model was chosen as the preferred regression model for the analysis. This ensured a robust and trustworthy examination of the relationship between green finance and the optimization of the agricultural industrial structure.
The obtained result was highly significant at the 1% level, as confirmed by the test, thus providing evidence to support Hypothesis 1 in this study. Based on the fixed-effects model, it was observed that a 1% increase in the level of improvement in green finance corresponded to a 0.599 increase in the level of upgrading of the agricultural industrial structure (as shown in
Table 9).
The control variables in this study exhibited important relationships with the optimization and upgrading of the agricultural industrial structure. Firstly, the level of rural human capital demonstrated a significant positive impact at the 1% level of significance. This suggests that an increase in rural human capital not only enhances the skills and knowledge of individuals in rural areas but also has spillover effects on technology adoption and management practices. The presence of a highly skilled rural workforce is crucial for driving innovation and facilitating the development of the agricultural industry. Moreover, the modernization and upgrading of the agricultural industrial structure heavily rely on the availability of a skilled labor force.
Secondly, the degree of marketization played a key role in promoting the development of regional industries. A higher level of marketization corresponds to increased demand for a wide range of industries and a greater flexibility in adjusting the industrial structure. However, it is important to note that during the adjustment phase, the marketization level may not effectively support the transformation and modernization of the agricultural industrial structure. This could be attributed to the unique characteristics of the agricultural sector, where market forces may not have a significant impact on agricultural sales and output due to factors such as price distortions and nonmarket influences. Additionally, the level of technological innovation in the agricultural sector is low in China compared to more advanced industrialized nations. Enhancing technological innovation is crucial for the modernization of the agricultural industrial system, and it requires increased investment in agricultural research and development, as well as the adoption of improved production techniques.
The control variables in this study, including rural human capital and marketization level, have important implications for the optimization and upgrading of the agricultural industrial structure. The findings highlight the significance of investing in human capital development, promoting marketization reforms, and fostering technological innovation to support the modernization and advancement of the agricultural sector.
4.6. Robustness Test
To ensure the robustness of the empirical findings, this study conducted two robustness tests. The first test involved Winsorizing the tail, which aimed to mitigate the potential influence of extreme values in the sample on the estimation results. Specifically, the main variables used in this analysis were subjected to a Winsorizing process of 1%, effectively reducing the impact of outliers. The second test focused on excluding municipalities directly under the Central Government. This was done to account for any potential bias resulting from specific policies that may favor these municipalities and their potential impact on the regression results. In this robustness test, the municipalities directly under the Central Government, namely Beijing, Tianjin, Shanghai, and Chongqing, were excluded from the research sample (as shown in
Table 10). By conducting these robustness tests, the study aimed to enhance the reliability and validity of the empirical results, ensuring that the findings were not overly influenced by extreme values or specific policies targeting municipalities directly under the Central Government.
A fixed-effects model (FE) was employed in this study, and it demonstrated its robustness by passing the significance test at a 1% level of significance with a 99% confidence level. The adoption of an FE model confirmed that for every 1% increase, the upgrading degree of the agricultural industrial structure expanded by 0.599. These findings indicate the consistent and reliable nature of the model, demonstrating that green finance plays a supportive role in the modernization of the agricultural industrial structure throughout the entire sample period. This conclusion is in alignment with the results obtained from the standard regression analysis.
4.7. Heterogeneity Analysis
The vastness of China’s territory gives rise to significant regional disparities in various aspects such as economic status, industrial structure, and resource endowment. As a result, the effects of green financing on the advancement of the agricultural industrial structure can differ between the eastern and western regions of China. This distinction is underscored by the findings presented in
Table 11, which highlight the unique dynamics and outcomes of green financing in these two regions.
A significant correlation existed between green finance and the optimization of the agricultural industrial structure in the eastern region. Green finance played a prominent role in promoting the optimization of the agricultural industrial structure at a 1% significance level. This could be attributed to the fact that the eastern region has historically prioritized resource-intensive industries as drivers of rapid economic development (as indicated in
Table 11).
However, the central and western regions exhibited slower development and lower levels of green finance, resulting in a weaker driving effect on the agricultural industry and a limited impact on the optimization and upgrading of the agricultural industrial structure. Quantitatively, the influence of green finance on the optimization of the agricultural industrial structure was significantly higher in the eastern region compared to the central and western regions. This disparity may be attributed to the higher level of green finance development and availability of green financial products in the eastern region. Additionally, the higher level of marketization in eastern China facilitated a smoother connection between green finance and industrial upgrading, thereby driving the advancement of the agricultural industry. Furthermore, the overall level of financial development in the eastern region was higher, leading to greater spillover effects that promoted the upgrading of the agricultural industry.
Notable regional differences existed in the impact of green finance development on the optimization of the agricultural industrial structure in the eastern, central, and western regions of China, thus confirming Hypothesis 2.