5.1. Descriptive Statistics
Using STATA software, descriptive statistics were performed on the mean, standard deviation, minimum, and maximum values for the selected sample. The specific results are shown in
Table 2.
From the table, we can observe that (1) after trimming the data at the 1% level, the maximum value of PAT (the indicator for green innovation ability) is 3.871, the minimum value is 0, and the mean is 0.420. This indicates that some enterprises exhibit strong green innovation capabilities in certain years, while others do not achieve green technological innovation in those years, reflecting significant differences in the green innovation performance of different enterprises. (2) In some years, the maximum value of OFDI (outward foreign direct investment) is 20.97, while the minimum value in other years is 5.09, with a mean of 16.22. This shows a large individual variation in the outward investment amounts between enterprises. (3) The maximum value of R&D investment is 24.63, the minimum is 0, and the mean is 17.195. This suggests that most enterprises allocate some amount of funds to R&D for technological innovation each year, but there are significant differences in R&D investment across enterprises. (4) Additionally, the dispersion of the other variables is relatively good, indicating that the selected sample has strong representativeness.
5.3. Baseline Regression Analysis
To examine the impact of outward foreign direct investment (OFDI) on the green innovation capability of enterprises, this paper first conducts a baseline regression of the constructed main model. The regression results are shown in
Table 4.
From columns (1) and (3) in the table, we can see that, regardless of whether industry and year fixed effects are controlled for, and without adding other control variables, the regression coefficient of OFDI is significantly positive at the 1% level. This indicates that OFDI significantly promotes green technological innovation.
From columns (2) and (4), when control variables such as debt-to-asset ratio, return on equity, book-to-market ratio, number of board members, proportion of independent directors, and proportion of fixed assets are included, the regression coefficient of OFDI remains significantly positive at the 1% level, regardless of whether industry and year fixed effects are controlled for. This further confirms that OFDI has a significant positive impact on green technological innovation, supporting Hypothesis 1.
5.4. Mediation Effect Test
After conducting the baseline regression analysis on the fixed-effects model established earlier, this paper aims to further understand the impact mechanism between outward foreign direct investment (OFDI) and green technological innovation, and whether the effects are positive or negative. To achieve this, a mediation effect model is constructed to further explore the path through which OFDI influences green innovation in enterprises.
As discussed in the theoretical analysis and baseline regression analysis, OFDI has a clear promoting effect on green technological innovation. Through OFDI, enterprises can achieve the effects of alleviating financing constraints and promoting R&D investment, and these two effects can enhance the green innovation capability of enterprises. To verify this mechanism, this paper establishes the following mediation effect model to test whether these two effects exist.
In the model, , , , , and are constant terms, and , , , , , , , , , and represent the estimated coefficients for each variable. i represents the outward foreign direct investment enterprises, and t represents the year of outward foreign direct investment. PAT denotes the number of green patent applications, which indicates the enterprise’s green innovation capability. OFDI is the core independent variable, which varies across individuals and time. SA represents financing constraints, RD represents R&D investment, and Control represents the set of control variables. represents the random disturbance term. Additionally, Industry and Year represent the fixed effects for controlling industry and year, respectively.
The mediation effect model constructed in this paper follows the transmission path:
- ①
As established in the baseline regression analysis using the fixed-effects Equation (2) in the previous section, we have already determined that outward foreign direct investment (OFDI) significantly promotes green technological innovation in enterprises.
- ②
According to Equation (3), we test whether the regression coefficient of the mediating variable SA (financing constraints) with respect to the core independent variable OFDI is significant, which reflects the relationship between outward foreign direct investment (OFDI) and financing constraints. Then, according to Equation (5), we test whether the regression coefficient of SA with respect to the dependent variable PAT (green patent applications) is significant, which reflects the relationship between green innovation capability and financing constraints.
- ③
According to Equation (4), we test whether the regression coefficient of the mediating variable RD (R&D investment) with respect to the core independent variable OFDI is significant, which reflects the relationship between outward foreign direct investment (OFDI) and R&D investment. Then, according to Equation (6), we test whether the regression coefficient of RD with respect to the dependent variable PAT (green patent applications) is significant, which reflects the relationship between green innovation capability and R&D investment.
- ④
If the regression coefficient of the mediating variable SA with respect to the core independent variable OFDI is significant, and the regression coefficient of SA with respect to the dependent variable PAT is also significant, it can be concluded that outward foreign direct investment (OFDI) can alleviate financing constraints, and the alleviation of these constraints can promote green technological innovation. Based on the conclusions of the previous study, it can be inferred that OFDI promotes green technological innovation. Therefore, the mediation effect model with SA as the mediating variable is valid.
- ⑤
When the regression coefficient of the mediating variable RD with respect to the core independent variable OFDI is significant, and the regression coefficient of RD with respect to the dependent variable PAT is also significant, it can be concluded that outward foreign direct investment (OFDI) promotes an increase in R&D investment, and the increase in R&D investment further promotes green technological innovation. Similarly, based on the previous research conclusions, it can be concluded that OFDI promotes green technological innovation. Therefore, the mediation model with RD as the mediating variable is valid.
Interpretation of the
Table 5: From the results of the regression in columns (1) and (2), we can observe that when financing constraints are included in the model, the regression coefficient of OFDI is significantly positive at the 1% level in column (1), and the regression coefficient of SA (financing constraints) is also significantly positive at the 1% level in column (2). This indicates that the model with financing constraints as the mediating variable is valid, and the mediation effect is significant. OFDI can alleviate financing constraints, which in turn promotes green technological innovation. This supports Hypothesis 2.
In columns (3) and (4), when R&D investment is added as another variable, the regression coefficient of OFDI remains significantly positive at the 1% level in column (3), and the regression coefficient of RD (R&D investment) is also significantly positive at the 1% level in column (4). This indicates that the model with R&D investment as the mediating variable is valid, and the mediation effect is significant. OFDI promotes an increase in R&D investment, which further fosters green technological innovation. This supports Hypothesis 3.
5.5. Robustness Check
(1) Substituting the Independent Variable
This paper uses the number of green patent applications by enterprises as an indicator to measure green innovation capability. To ensure the robustness of the empirical results, the paper employs a substitution approach for the independent variable. Specifically, the variable for outward foreign direct investment (OFDI) is replaced with the number of times a company makes outward foreign direct investments (denoted as “TOFDI” in this paper). This new variable is then incorporated into the previously constructed fixed-effects Equation (2) for baseline regression, controlling for industry and year fixed effects. The regression results are presented in
Table 6.
From column (1) of the table, we can see that the regression coefficient for the new independent variable TOFDI is significantly positive at the 5% level. Although the coefficient differs slightly from the original core independent variable OFDI, the regression result remains significantly positive. This suggests that the conclusion from the previous baseline regression, that OFDI significantly promotes green technological innovation, still holds true, and further confirms the robustness and reliability of the baseline regression results.
(2) Adding Control Variables
In previous studies, many scholars have focused on the enterprises themselves, noting that the promotion of green technological innovation through OFDI is not only related to the OFDI behavior but also to the operational conditions of the listed companies. Therefore, this paper adds a new control variable—the enterprise’s main business income growth rate (denoted as “GROWTH”). This variable is incorporated into the previously constructed fixed-effects Equation (1) for baseline regression, controlling for industry and year fixed effects. The regression results are shown in column (2) of
Table 6.
From column (2) of the table, we can observe that the new control variable GROWTH has a significantly positive regression coefficient at the 1% level, and the regression coefficient for OFDI remains significantly positive at the 1% level. This result suggests that an increase in the business income growth rate significantly promotes green technological innovation, i.e., a company’s good operational condition benefits its green technological innovation. Therefore, as long as the main business income growth rate remains positive, OFDI continues to significantly promote green technological innovation, further validating the robustness and reliability of the baseline regression results.
(3) Lagging the Independent Variable
Based on the previous empirical research, it is known that OFDI significantly promotes green technological innovation. However, it is also possible that green technological innovation may promote OFDI, suggesting that there could be potential endogeneity issues, i.e., a bidirectional causal relationship between OFDI and green innovation. To address this, the paper lags the independent variable by one period. The core independent variable OFDI is treated as a lagged variable (denoted as “L.OFDI” in this paper), and industry and year fixed effects are still controlled. The baseline regression results are shown in column (3) of
Table 6.
From column (3) of the table, we see that L.OFDI is significantly positive at the 1% level. This indicates that the endogeneity issue between OFDI and green technological innovation is not prominent, and OFDI still significantly promotes green technological innovation. This suggests that after addressing the potential endogeneity issue, the research conclusions remain valid, further confirming the robustness of the baseline regression results.
(4) GMM Dynamic Panel Analysis
Since green technological innovation in enterprises tends to exhibit persistence over time, i.e., a serial correlation issue, this paper uses the system GMM estimation to address this issue. From column (4) of
Table 6, we can see that the regression coefficient for OFDI is still significantly positive at the 5% level. This shows that even after considering the serial correlation in green technological innovation, OFDI continues to significantly promote green technological innovation. This further validates the stability of the baseline regression results.
5.6. Heterogeneity Analysis
(1) Green Patent Heterogeneity Analysis
This study categorizes corporate green technological innovation into substantive green innovation and superficial green innovation. Substantive green innovation refers to the number of green invention patents (denoted as “INVPAT”) applied for by enterprises in a given year. This type of innovation fundamentally alters the nature of a product and represents a higher level of technological advancement. In contrast, superficial green innovation refers to the number of green utility model patents (denoted as “UTYPAT”) applied for by enterprises in a given year. This form of innovation involves modifications to a product’s external characteristics without altering its core functionality (Wang, X. et al., 2022) [
42].
The regression results from the subsample discussion are shown in
Table 7. From columns (1) and (2), we observe that the regression coefficients for OFDI are significantly positive at the 1% level, indicating that outward foreign direct investment (OFDI) promotes both substantive and surface-level green innovation. However, the regression coefficient for substantive green innovation is slightly larger than that for surface-level green innovation, suggesting that OFDI has a more significant effect on substantive green innovation. This may be because enterprises engaging in outward foreign direct investment are more focused on substantive green innovations that enhance their competitive advantage and demonstrate their technological strength, which supports long-term and stable OFDI activities. Although surface-level green innovation increases the number of green patent applications, it does not genuinely enhance the enterprise’s green innovation capabilities. Therefore, enterprises tend to prioritize substantive green innovations and focus more on applying for green invention patents.
(2) Enterprise Ownership Heterogeneity Analysis
The innovation efficiency of enterprises is related to their ownership structure. According to economic classifications, China’s enterprises can be divided into state-owned enterprises (SOEs), private enterprises, joint-stock companies, and other types. This classification is based on the nature of the asset owner. In this paper, the sample is divided into SOEs and non-SOEs to explore the differences in the impact of OFDI on green technological innovation based on ownership structure. The regression results are shown in
Table 8, where column (1) represents the regression results for SOEs and column (2) represents the results for non-SOEs.
From column (1), it can be seen that for SOEs, the regression coefficient of OFDI is significantly positive at the 1% level, indicating that OFDI significantly promotes green technological innovation in SOEs. From column (2), it can be seen that for non-SOEs, the regression coefficient of OFDI is not significant, suggesting that OFDI does not promote green technological innovation in non-SOEs.
This is because state-owned enterprises (SOEs) hold a unique economic position in China, serving as a barometer of government policies (Zhao, J. and Lee, J., 2020) [
43]. Consequently, benefiting from ownership policy advantages and substantial government financial support, these enterprises exhibit a higher propensity for outward foreign direct investment (OFDI). Moreover, SOEs possess stronger research teams and a greater number of high-quality research projects, enabling them to rapidly absorb and adopt advanced green technologies from foreign markets (Li, Y. et al., 2024) [
44]. Additionally, in terms of financing, non-SOEs face higher borrowing costs from banks and other financial institutions compared to SOEs. This financial disadvantage often leads to funding shortages, which in turn constrains R&D investment in non-SOEs.
(3) Enterprise Pollution Degree Heterogeneity Analysis
To explore whether OFDI has different effects on green technological innovation for enterprises with varying pollution levels, this paper challenges the assumption of homogeneity regarding the pollution levels of enterprises. It classifies listed companies into polluting and non-polluting enterprises, based on the “Environmental Information Disclosure Guidelines” issued by the Ministry of Ecology and Environment of the People’s Republic of China. The regression results are shown in
Table 9, with column (1) representing the results for polluting enterprises and column (2) representing the results for non-polluting enterprises.
From column (1), it can be seen that for polluting enterprises, the regression coefficient of OFDI is only significant at the 10% level, indicating that the effect of OFDI on green technological innovation is not very pronounced for polluting enterprises. In contrast, from column (2), it can be seen that for non-polluting enterprises, the regression coefficient of OFDI is significantly positive at the 1% level, indicating that OFDI significantly promotes green technological innovation in non-polluting enterprises. Compared to non-polluting enterprises, the impact of OFDI on promoting green innovation is weaker for polluting enterprises.
This is because operating in international markets is inherently a long-term process, requiring enterprises to continuously expand and gradually adapt to foreign markets. As a result, the costs incurred in overseas expansion are difficult to translate into immediate financial returns in the short run (Xu, L.E. et al., 2021) [
45]. Compared to non-polluting enterprises, polluting enterprises engage in outward foreign direct investment (OFDI) primarily to relocate their production processes with high pollution emissions—those that are more likely to face penalties, stricter regulations, or even shutdowns from domestic environmental authorities—to overseas regions. These enterprises tend to shift such activities to less developed countries and regions that have not yet prioritized environmental protection policies (Tolliver, C. et al., 2020; Bai, Y. et al., 2020) [
46,
47]. As a result, polluting enterprises are more inclined to sustain their regular overseas operations rather than allocate financial resources to green innovation initiatives. Furthermore, investing in green innovation projects entails significantly higher costs and greater risks, making it a less attractive option for polluting enterprises.