3.1. Correlation Between Investment Environment Elements and Natural Environment Variables-G7
Table 1 presents the results generated by SPSS 27 for testing the assumption of normality using the Shapiro–Wilk test. This test determines whether the dataset follows a normal distribution, which in turn informs the appropriate application of either parametric or non-parametric statistical models. The results indicate that most variables do not follow a normal distribution. Consequently, the use of Spearman’s rank correlation coefficient, a non-parametric statistical method, is justified.
Table 2 presents the results of the Spearman correlation analysis between the elements of the natural environment (preservation efforts, oceans, freshwater, forests, land and soil, air pollution exposure, and emissions) and economic growth in the G7 countries: Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States.
The Spearman correlation coefficient allows for the interpretation of both the strength and direction of the correlation between the components of the independent variables and the dependent variable (economic growth).
The results from the Spearman correlation analysis reveal statistically significant associations between per capita GDP and several environmental dimensions. A significant negative correlation was observed between per capita GDP and emissions (ρ = −0.505, p < 0.001), suggesting that higher income levels in these countries are associated with lower levels of environmental emissions.
Additionally, per capita GDP shows significant positive correlations with the following:
Air pollution exposure (ρ = 0.498, p < 0.001);
Forests and land and soil indicators (ρ = 0.375, p < 0.001);
Ocean conditions (ρ = 0.614, p < 0.001).
These relationships may reflect the coexistence of economic growth with localized environmental pressures, or potentially a greater monitoring and reporting capacity in higher income countries.
In contrast, the correlation between per capita GDP and freshwater availability (ρ = 0.169, p = 0.067) is not statistically significant. Similarly, no significant association is found with preservation efforts (ρ = −0.007, p = 0.938), indicating that income levels are not systematically linked with this environmental dimension across the G7 countries analyzed.
3.2. Correlation Between Investment Environment Elements and Natural Environment Variables-ALADI
Table 3 presents the results of Spearman’s Rho correlation analysis between elements of the natural environment—namely preservation efforts, oceans, freshwater, forests, land and soil, air pollution exposure, and emissions—and economic growth in ALADI countries, including Argentina, Bolivia, Brazil, Chile, Colombia, Cuba, Ecuador, Mexico, Panama, Paraguay, Peru, Uruguay, and Venezuela.
The results show a moderate and statistically significant positive correlation between per capita GDP and environmental emissions (ρ = 0.327, p < 0.001), as well as with air pollution exposure (ρ = 0.345, p < 0.001). These associations suggest that higher income levels in the analyzed ALADI countries are linked to increased environmental pressure, particularly in terms of emissions and air quality. This may reflect resource-intensive consumption and production patterns associated with advanced stages of industrialization.
A significant positive correlation was also found with freshwater availability (ρ = 0.422, p < 0.001), indicating that some economies may possess a better capacity to manage water resources efficiently. Similarly, a weaker but still statistically significant positive correlation was observed with the state of the oceans (ρ = 0.209, p = 0.004), which might be associated with localized monitoring, marine conservation efforts, or the presence of high-value coastal economic activities.
In contrast, no significant relationship was identified between GDP per capita and forests and land and soil (ρ = 0.033, p = 0.621). More notably, a significant negative correlation was found with preservation efforts (ρ = −0.446, p < 0.001), suggesting that higher income levels do not necessarily translate into greater investment in environmental conservation policies.
3.3. Unit Root Stationarity Test of Environmental and Economic Variables
The stationarity test applied to both environmental and economic variables demonstrates that all time series are at a stationary level, as the
p-values associated with the adjusted t-statistics are below the 5% significance threshold. This allows for the rejection of the null hypothesis of a unit root presence and confirms that the series exhibit constant statistical properties over time (see
Table 4).
Table 5 presents the results of the multicollinearity analysis. The findings indicate that no multicollinearity exists among the independent variables included in the model. This validates the application of regression models without concern for inflated variances or distorted coefficient estimates due to inter-variable correlation.
The results indicate that all Variance Inflation Factor (VIF) values are below the conventional threshold of 5, suggesting no severe multicollinearity among the explanatory variables. Therefore, the model estimates are not significantly biased due to inter-variable linear dependence, as detailed in
Table 5.
To assess other assumptions of the panel data regression model, tests for autocorrelation and heteroskedasticity were performed. As shown in
Table 6, the Wooldridge test for autocorrelation indicated the presence of first-order autocorrelation in the panel data, with an F-statistic of 19.883 and a
p-value of 0.0043—allowing for the rejection of the null hypothesis of no autocorrelation.
Likewise, the presence of groupwise heteroskedasticity was tested using the Modified Wald test, whose results are presented in
Table 7. The test yields a Chi-squared value of 181.69 with a
p-value of 0.0000, rejecting the null hypothesis of homoskedasticity across panels.
These findings confirm that both autocorrelation and heteroskedasticity are present in the data. To address these issues and ensure the accuracy of standard error estimates, the model was corrected using Panel Corrected Standard Errors (PCSE), improving the robustness and reliability of the econometric results.
The results confirm the presence of both autocorrelation and heteroskedasticity in the panel data in
Table 8. To address these issues and ensure robust standard error estimates, the models were corrected using Panel Corrected Standard Errors (PCSEs). This correction enhanced the accuracy of inference and strengthenedthe robustness of the econometric results. The corrected fixed effects models are presented at the end of the Results section.
Although both models show similar results in terms of global significance and the influence of key variables on economic growth, the observed differences in coefficient estimates justify the need for a Hausman test to determine which model better fits the data.
The results shown in
Table 9 indicate significant differences in the coefficients estimated by the fixed effects and random effects models. This difference suggests that the two models yield substantially different interpretations of the relationship between the explanatory variables and economic growth.
Given the Chi-square statistic of 24.59 and a p-value of 0.0062, we reject the null hypothesis that the random effects model is more appropriate. Since the p-value is less than 5%, we conclude that the fixed effects model provides a better fit for the panel data under study. This outcome confirms the presence of a correlation between unobserved individual effects and the explanatory variables, violating the assumption of independence required by the random effects model.
Accordingly, the fixed effects panel model is selected as the most appropriate specification for analyzing the relationship between environmental factors and economic growth across the countries in the study.
The fixed effects panel regression model applied to the G7 countries reveals that three environmental variables are statistically significant in explaining changes in economic growth. As shown in
Table 10, two of these variables exhibit a negative and statistically significant relationship with per capita GDP.
Specifically, the variable “Emissions” presents a coefficient of −710.923 and a p-value of 0.000, indicating a strong inverse relationship with economic growth. This suggests that higher emission levels are associated with lower per capita GDP, pointing to the environmental and economic cost of pollution in developed countries.
Likewise, the variable “Forests and Land and Soil” also displays a significant negative effect on economic growth, with a coefficient of −419.813 and a p-value of 0.000. This underscores the importance of sustainable land management and environmental preservation for maintaining long-term growth in developed economies.
In addition, the variable “Air Pollution Exposure” shows a positive effect that is marginally significant (p = 0.056), while “Freshwater” (p = 0.066) and “Preservation Efforts” (p = 0.065) approach significance and may warrant further investigation. The variable “Oceans” is not statistically significant in this model.
The model’s explanatory power is high, with an adjusted R-squared of 0.8464, indicating that approximately 85% of the variation in per capita GDP can be explained by the selected environmental variables. The overall model significance (p = 0.0000) further confirms the robustness and reliability of the fixed effects specification.
The results of the fixed effects panel regression model for ALADI countries are presented in
Table 11. Two variables emerge as statistically significant in influencing economic growth in this group of developing countries.
The first is “Emissions”, which displays a negative relationship with economic growth, with a coefficient of −212.4162 and a p-value of 0.015. This indicates that higher levels of greenhouse gas emissions are significantly associated with lower levels of per capita GDP in these countries. The result suggests that economic and environmental costs are closely linked, and that high emission levels can constrain long-term sustainable growth. To mitigate this impact and support economic expansion, it would be prudent for these nations to adopt standards and targets aimed at reducing emissions and their negative effects on economic performance.
The second significant variable is “Air Pollution Exposure”, which shows a positive coefficient of 172.888 and a p-value of 0.001. This suggests that increases in industrial activity, urbanization, and economic production, often occurring in settings with weak environmental regulations, may drive short-term GDP growth. However, while this dynamic may stimulate economic expansion in the near term, it raises concerns about sustainability, as the associated environmental and health impacts may lead to higher long-term social and economic costs, undermining overall well-being and development.
As shown in
Table 11, the variables “Forests and Land and Soil”, “Freshwater”, “Oceans”, and “Preservation Efforts” did not show statistically significant relationships with economic growth in this model.
The model reports an R-squared of 0.3941, indicating a moderate explanatory power, meaning that approximately 39% of the variation in per capita GDP is explained by the environmental variables included in the model. Furthermore, the overall model significance (p = 0.0000) confirms the validity of the fixed effects specification for this group of developing countries.