Gross Domestic Product (ECL) is widely regarded as a major engine of economic development, shaping the resources available to enhance life expectancy at birth (LEX). Policies that encourage technological advancement, boost business productivity, and generate employment have a direct effect on public health by improving access to healthcare, sanitation, and education. With higher ECL, governments typically have greater capacity to invest in infrastructure and healthcare systems, ultimately leading to longer life expectancy (20). However, although it is often believed that countries rich in natural resource rents (NRR) and renewable energy consumption (REC) will achieve rapid ECL growth, this expectation does not always hold true (21). It is important to recognize that economic level does not automatically stem from resource abundance; in fact, excessive dependence on natural resource extraction can hinder economic diversification, ultimately limiting its long-term benefits for public health and life expectancy (22).

Empirical research also highlights the positive link between trade openness, life expectancy at birth (LEX), and ECL. A panel analysis of Balkan countries from 2000 to 2019 revealed that trade openness and LEX both had significant positive effects on ECL growth, underscoring their role in enhancing economic performance and promoting public health (23). Likewise, in BRICS countries, financial development (FDI) inflows have been mainly fueled by ECL growth, while factors like political stability and life expectancy at birth (LEX) serve a supporting role in advancing public health by raising living standards (24). LEX and ECL growth reinforce each other in attracting foreign investment, indicating that strengthening health and social infrastructure can boost economic stability while also increasing life expectancy (25).

The relationship between financial development (FDI) and life expectancy at birth (LEX) has been extensively examined, especially in the context of developing countries (26). Financial development is essential for enhancing healthcare access by enabling greater investment in the health sector, expanding educational opportunities, and supporting overall well-being. (27) examined the uneven relationship between FDI, ECL, and LEX in ASEAN countries, showing that although both ECL and FDI have positive impacts on LEX, the long-term effects of FDI are asymmetric. Nwani (28) showed that over the long term, Nigeria’s ECL is strongly affected by LEX, supporting the view that better public health directly fosters sustainable economic level.

Moreover, Ibrahim (29) revealed that although rising income levels in Africa are linked to environmental degradation, advancements in trade, life expectancy at birth (LEX), and renewable energy consumption (REC) improve environmental quality by lowering the ecological footprint. This indicates that LEX serves as a mediating factor in reconciling economic level with environmental sustainability. Xu et al. (17) also suggest that LEX acts as a catalyst in enhancing the positive impact of REC on ECL, highlighting the strong link between renewable energy consumption, public health, and economic level. Recent studies also highlight the role of green finance in promoting energy efficiency and supporting sustainable urban development, underscoring the importance of financial sector development for achieving environmental and health goals (30). Financial development is essential for enhancing healthcare access by enabling greater investment in the health sector, expanding educational opportunities, and supporting overall well-being. This underscores the critical role of financial development in advancing both health outcomes and environmental sustainability.

In emerging economies rich in natural resource rents, low life expectancy at birth (LEX) is frequently linked to the resource curse, where heavy reliance on resource extraction results in economic stagnation and environmental harm, ultimately lowering life expectancy (31). The United Nations Development Program points out that overexploitation of resources has led to serious environmental issues—such as deforestation, soil erosion, and loss of biodiversity especially in emerging economies like the E7 and N11 countries (32). However, improvements in LEX can help turn the resource curse into an economic benefit by fostering knowledge-driven industries and decreasing dependence on raw material exports (33). Nonetheless, Lyatuu et al. (34) warn that mineral rents may adversely affect LEX development, depending on how heavily a country’s economy relies on them. In this study, natural resources are operationalized as natural resource rents as a percentage of GDP, capturing the economic value derived from extractive industries. While governance quality is widely recognized as a critical factor moderating the resource–health relationship, it is not directly included in our model, and this limitation is acknowledged in our analysis.

Previous studies generally confirm a positive association between economic growth and life expectancy, suggesting that higher income levels improve access to healthcare, nutrition, and living standards. However, most of these studies estimate only the mean effect of income on health, leaving unanswered whether the benefits of economic development are equally shared across populations with different health outcomes (35). This raises the question of whether economic growth reduces or reinforces health inequalities an issue this study seeks to address.

A growing body of work links renewable energy consumption with improved health outcomes, primarily through reductions in air pollution and environmental degradation (36). While these findings are consistent, the literature has not fully explored whether the health benefits of renewable energy are uniform across populations. Little is known about whether renewable energy consumption benefits those with already higher life expectancy than those with lower life expectancy, which is a critical dimension of health inequality.

Financial development has been shown to improve health outcomes by increasing access to capital, promoting healthcare investment, and fostering inclusive growth (35). Yet, studies disagree on whether financial flows benefit the entire population equally or disproportionately favor specific groups. The distributional impacts of finance on health remain unclear, which justifies investigating these effects across different life-expectancy levels.

Research on natural resources suggests that rents from resource exploitation often undermine health outcomes by fostering economic volatility, weak institutions, and environmental harm. Nonetheless, the evidence is mixed, with some studies indicating positive effects under strong governance (37). These inconsistencies highlight the importance of examining how resource dependence affects health across different segments of the population, rather than only on average.

Education and access to clean water are widely recognized as fundamental drivers of health improvement (35). However, existing studies often examine these variables as controls rather than as central determinants. Moreover, their distributional effects across different health levels have not been systematically investigated, despite their critical role in reducing health inequalities.

Given the varied economic conditions and resource endowments among E7 countries, it is essential to analyze how ECL, REC, FDI, and NRR influence LEX in this group. This study explores these relationships over the period 2000 to 2022, using advanced econometric methods such as stability analysis, matrix correlation, CIPS unit root tests, slope heterogeneity, Westerlund cointegration, and Method of Moments Quantile Regression (MMQR) to ensure robust and reliable results. By examining the key factors affecting LEX, this research offers important insights for policymakers to develop strategies that support economic level while prioritizing public health and human well-being.

Ultimately, a country’s development and prosperity depend on its Life Expectancy at Birth (LEX), which serves as a broad indicator of public health and overall well-being. The economic level is strongly linked to rising LEX, highlighting the importance of understanding how ECL, REC, FDI, and NRR impact health outcomes. This literature review emphasizes the need for a balanced strategy that combines economic level, responsible resource management, and sustainable public health initiatives to achieve lasting national and global progress.

Based on the preceding theoretical foundations, the interactions between ECL, REC, FDI, NRR, and LEX can be represented as follows:

Natural Resource Rents (NRR) → Life Expectancy (LEX): The effect of natural resource rents on life expectancy is shaped by how they are managed. Countries that steward their resource wealth effectively can enhance health outcomes, whereas poor governance can lead to adverse public health impacts.

Based on the conceptual framework, the following research hypotheses are formulated:

This conceptual framework serves as the basis for examining the complex interactions between economic factors and public health outcomes in E7 countries. The specified relationships will be empirically tested using the Method of Moments Quantile Regression (MMQR) approach, which accounts for distributional heterogeneity and offers robust insights into the determinants of Life Expectancy at Birth (LEX).

The analysis begins with descriptive statistics and normality tests for each variable. A correlation matrix for the panel data is also calculated. Correlation analysis helps evaluate data validity and reliability, as strong or weak correlations between related variables may indicate measurement consistency or inconsistency.

Prior to estimating the regression model, several steps were taken to confirm the presence of a long-term relationship between the dependent and independent variables. Given the possibility of unobserved common shocks and shared determinants across countries—which can affect the statistical properties of panel unit root tests, the study tests for cross-sectional dependence and slope heterogeneity. Cross-sectional dependence is a key issue in econometric analysis that can compromise empirical results. Applying tests for cross-section dependence enables researchers to detect and address this challenge effectively. This strengthens the accuracy and credibility of the results, supporting more reliable economic analysis and policymaking. The estimation relies on Equation 2, the Pesaran (48) CD (Cross-Sectional Dependence) test is administered:

Considering the usual panel-data model where β is a K × 1 vector of parameters that need to be estimated, α i is a time-invariant individual nuisance parameter, and x it is a vector of regressors. It is assumed to be independent and identically distributed. Spanning time periods and across cross-sectional units under the null hypothesis the alternative u it maintains the presumption of no serial correlation but allows for possible cross-sectional correlation. Which panel unit root tests need to be used is determined by the first step results. Because first-generation panel unit root tests are likely to be biased in the presence of cross-sectional dependency and slope heterogeneity, we directly investigate the CIPS unit root. The Westerlund (49) test is then used to look at the variables’ long-term connection. Besides, a statistical study is usually used to discover the variation in slopes among various groups or situations in the slope heterogeneity test. Slope heterogeneity is an advantageous test for analyzing the comparative regression in line slopes and statistical differences. Researchers can learn more about the phenomena they are researching and, depending on the test outcomes, can make better conclusions by conducting slope heterogeneity tests. Subsequently, econometric techniques such as the Cross-Sectionally Augmented IPS (CIPS) unit root test, are employed to examine time series data and mark if a variable is stationary or shows a unit root. CIPS test is specifically helpful in examining panel data or time series data that might exhibit cross-sectional correlation. In addition, CIPS test yields accurate inference since it incorporates the cross-sectional dimension. The Equation 3 for the CIPS test:

where ln ( Pt / Pt − 1 ) is the price ratio’s logarithm, α is the constant term, β is the trend term’s coefficient, t is the time variable, and εt is the error term. Westerlund analysis sheds important light on the outcomes of the intervention under inspection. The meticulous methodology and in-depth analysis add to the body of knowledge already available in the subject and provide possible directions for further examination. This Westerlund analysis is given in Equation 4 as follows:

The dependent variable in this equation is denoted by Y , and the independent variables are X and Z . The error term is ε , and the coefficients that need to be estimated are a , b and c. Once cointegration has been validated, we need to use an unbiased and consistent estimator such as MMQR model. With panel data, where extreme values and outliers might arise from individual or time-specific features, MMQR offers a strong framework for determining the correlations between variables. Equation 1 illustrates the summarization of MMQR test technique. Time-varying effects can be handled by MMQR by allowing the coefficients to change over various quantiles and time intervals. Endogeneity and selection bias problems that are frequently seen in panel research can be addressed with the assistance of MMQR. However, MMQR is significantly true for panel research because MMQR analysis can reduce biased results from sample selection or unobserved heterogeneity by permitting quantile-specific effects. Research workers can examine the heterogenous impacts, identify the non-linear connections, and offer insightful data for better plans and policy analysis through comprehensive and flexible framework of panel data.

Taken together, these theoretical perspectives provide a multidimensional lens for analyzing the determinants of life expectancy in the E7 countries. The modernization theory highlights how rising economic levels (ECL) can promote improvements in living standards and healthcare, thereby enhancing life expectancy. In contrast, the resource curse theory warns that excessive dependence on natural resource rents (NRR) may undermine long-term development and public health outcomes. Meanwhile, the ecological modernization framework emphasizes the potential of renewable energy consumption (REC) to reconcile economic growth with environmental sustainability, while theories of financial development suggest that efficient financial development (FDI) can support investment in health-related infrastructure. By linking these theories, we construct an integrated analytical framework that recognizes both the positive and negative channels through which economic and environmental factors may affect life expectancy. This provides the basis for the research hypotheses developed in the next section.

This section presents a comprehensive interpretation of the study’s findings based on various econometric analyses, including the correlation matrix, cross-sectional dependence, unit root testing, cointegration analysis, and Method of Moments Quantile Regression (MMQR). The results are discussed considering their implications for Life Expectancy at Birth (LEX) across the E7 countries.

Table 3 presents the correlation matrix. The correlation matrix reveals some intriguing patterns. Notably, LEX is positively correlated with FDI and NRR at significant levels (0.33 and 0.68, respectively), indicating that greater financial development and natural resource rents are associated with higher life expectancy. However, the relationship between ECL and LEX is weak and slightly negative (0.09), while REC shows a more substantial negative correlation with LEX (−0.58), suggesting that the expansion of renewable energy consumption might not directly correlate with improved life expectancy in the sample countries.

The correlation results show simple, unconditional associations, while the regression results (MMQR) capture conditional effects after controlling other factors. This explains why some signs are different.

For example, renewable energy consumption (REC) shows a negative correlation with life expectancy (LEX) but turns positive in the regression. This is because in several E7 countries with lower life expectancy, a large share of “renewables” comes from traditional biomass (wood, charcoal), which harms health through indoor pollution. After controlling for income, literacy, and clean water access, the positive health benefits of modern renewables (solar, hydro, wind) become clear in the regression.

Similarly, natural resource rents (NRR) appear positively correlated with life expectancy in the simple correlation, since resource-rich countries often also have higher incomes. However, once income and social infrastructure are held constant, the regression shows a negative effect, consistent with the “resource curse” (volatility, governance risks, environmental damage).

Therefore, the differences between correlations and regressions are not contradictions, but reflect the distinction between unconditional associations and conditional, distribution-sensitive effects.

Table 4 presents the results of the cross-sectional dependence analysis, indicating a statistically significant association between the independent variables (ECL, REC, FDI, NRR) and the dependent variable (LEX), with a p-value of 0.00. This confirms the presence of cross-sectional dependence among the variables, suggesting that the economic and environmental dynamics of one country can influence those of others. This finding is important, as it calls for the application of models that account for these dependencies, such as the Pesaran and Yamagata (55) test and the CIPS unit root test.

Table 5 provides the results of the slope heterogeneity analysis, which highlights significant variation across countries in terms of their responses to the independent variables. The results of this test (Delta: 11.252, adjusted: 13.088) further emphasize the necessity of accounting for individual country-specific effects in the analysis, ensuring that the heterogeneity across the E7 countries is appropriately captured.

Table 6 shows the results of the Cross-sectionally Augmented IPS (CIPS) unit root test, confirming that all variables are stationary after first differencing [denoted by the significant values at I(1) level]. This confirms the reliability of the data for further econometric analysis, allowing the investigation of long-term relationships among the variables.

Table 7 presents the Westerlund cointegration test results, which confirm the existence of a long-term equilibrium relationship between LEX, ECL, REC, FDI, and NRR. Specifically, the Gt and Pt statistics are highly significant, indicating a stable long-run relationship among these variables. This finding supports the hypothesis that the economic and environmental factors investigated in this study influence LEX over time, necessitating further analysis of these relationships using a robust model such as MMQR.

The core findings of the empirical analysis are presented in Table 8, which displays the results of the MMQR across different quantiles (0.25, 0.50, 0.75, and 0.90) of life expectancy at birth (LEX). These results reveal how the impacts of ECL, renewable energy consumption (REC), financial development (FDI), and natural resource rents (NRR) differ across various stages of life expectancy in E7 economies.

At the lower quantile (0.25), ECL and REC exhibit positive and statistically significant effects on LEX, with coefficients of 0.1821 and 0.0127, respectively. However, the magnitude of these effects remains relatively modest, suggesting that in E7 countries with lower levels of life expectancy, economic level and renewable energy consumption adoption contribute only marginally to public health improvements. In contrast, FDI demonstrates a stronger positive effect (0.1321), indicating that financial sector development is a key driver of better health outcomes at early stages of development. Interestingly, NRR shows a significant negative relationship with LEX (−0.0476), implying that reliance on natural resource exploitation in these economies may be detrimental to health progress, possibly due to governance challenges, environmental degradation, or the misallocation of resource revenues.

As we move to the median quantile (0.50), the positive effects of ECL (0.2021) and REC (0.01193) become slightly stronger, although the contribution of REC remains relatively small. FDI’s influence on LEX also intensifies (0.1616), highlighting that as life expectancy improves in E7 countries, financial development plays an increasingly vital role in fostering better living standards, healthcare access, and educational outcomes. Nonetheless, NRR continues to exert a negative effect (−0.0468), suggesting that even as countries achieve moderate levels of life expectancy, the adverse consequences of resource dependence persist.

At the higher quantiles (0.75 and 0.90), the positive coefficients for ECL (0.2201 and 0.2351) and REC (0.0112 and 0.0105) remain statistically significant but show a pattern of diminishing returns. This indicates that in E7 countries with higher life expectancy, additional economic level and renewable energy consumption use do not translate into proportionately greater improvements in public health. Meanwhile, the positive impact of FDI becomes even more pronounced (0.1887 and 0.2120), reinforcing the critical role of financial systems in sustaining health and welfare gains in more advanced stages of development. NRR continues its negative and significant influence (−0.0460 and −0.0454), suggesting that resource-related challenges remain a structural barrier to further life expectancy gains, even among relatively high-performing E7 nations.

Figure 2 shows how the impact of key independent variables on life expectancy at birth varies across different quantiles in E7 economies. Economic Level (ECL), Financial Development (FDI), Adult Literacy Rate (ALR), and Access to Improved Water Sources (AIWS) all exhibit clearly increasing coefficients across higher quantiles. This indicates that their positive influence on life expectancy becomes stronger at higher levels of health outcomes, suggesting that wealthier or healthier segments of the population benefit disproportionately from gains in these areas. In contrast, Renewable Energy Consumption (REC) displays a modest but consistent decrease in its coefficient across quantiles, implying a diminishing marginal effect. Natural Resource Rents (NRR) remain negatively associated with life expectancy throughout but become slightly less negative at higher quantiles, indicating persistent but somewhat weaker adverse effects for populations with already higher life expectancy. These findings highlight the importance of targeted policy interventions that address inequality in health outcomes, emphasizing the need for broader investments in education, water infrastructure, and financial systems while managing resource dependence responsibly.

Table 9 presents robustness checks using four alternative estimation techniques: Augmented Mean Group (AMG), Common Correlated Effects Mean Group (CCEMG), Fully Modified Ordinary Least Squares (FMOLS), and Dynamic Ordinary Least Squares (DOLS). The signs, magnitudes, and significance levels of the coefficients remain broadly consistent with the baseline Method of Moments Quantile Regression (MMQR) results, confirming the stability of the findings. Specifically, economic level (ECL), renewable energy consumption (REC), financial development (FDI), adult literacy rate (ALR), and access to improved water sources (AIWS) continue to exert significant positive effects on life expectancy (LEX), while natural resource rents (NRR) maintain a negative association. This consistency across multiple estimators underscores the robustness and reliability of the established relationships. The results emphasize that while economic level and renewable energy consumption contribute positively to life expectancy in E7, their impacts are relatively modest and tend to diminish as development progresses. In contrast, financial development emerges as a consistently strong and growing driver of life expectancy improvements across all quantiles. The persistent negative association between natural resource dependence and life expectancy highlights the need for E7 countries to manage their resource wealth more effectively and to invest in broader social and economic development to achieve sustainable improvements in public health. Figure 3 exhibits relationships of dependent and independent variables.

The empirical findings provide important insights into the determinants of life expectancy at birth (LEX) in E7 countries, offering a more nuanced understanding than previous studies:

The positive and statistically significant association between ECL and LEX at various development stages aligns with existing research linking economic level to improved public health through higher incomes, better healthcare infrastructure, and education (8). However, the relatively small effect size and the decreasing impact at higher levels of life expectancy question the traditional assumption of a strong, linear link between economic level and health outcomes (50). This indicates that in E7 countries, although economic level continues to play a vital role, their ability to further improve health outcomes diminishes as development progresses, highlighting the importance of additional social investments beyond simply increasing ECL.

The results related to renewable energy consumption (REC) add a valuable dimension to the existing literature. While prior studies (51, 52) emphasizing the environmental and health co-benefits of renewable energy consumption, this analysis indicates that REC’s impact on LEX, though positive and statistically significant, is relatively modest. Additionally, its effect diminishes slightly at higher levels of life expectancy. These findings call into question overly optimistic assertions that renewable energy consumption transitions alone can deliver major public health gains without accompanying socio-economic and healthcare sector reforms.

A particularly important finding is the consistently strong and increasingly positive effect of financial development (FDI) on life expectancy across all quantiles. This aligns with the work of Nica et al. (53) and Shi et al. (54), highlighting the essential role of financial systems in expanding access to healthcare, supporting investments in education, and alleviating poverty. Unlike traditional perspectives that often treat financial development as secondary to ECL, these findings identify financial sector growth as a key driver of life expectancy improvements across various stages of development in E7 countries. This challenges earlier frameworks that have neglected the health-promoting potential of inclusive financial systems.

The inverse relationship between natural resource rents dependence (NRR) and LEX provides strong evidence in favor of the resource curse hypothesis (46), but broadens its relevance to the public health sphere, which is often overlooked in discussions of the resource curse. The consistently negative impact across all levels of life expectancy indicates that governance issues, environmental damage, and poor management of resource wealth substantially impede health improvements. This challenges the belief held by some scholars and policymakers that resource revenues can easily be used to fund better health outcomes, underscoring the importance of improved governance, greater transparency, and economic diversification strategies.

Overall, these findings present a more nuanced perspective than is often found in the existing literature. Instead of treating economic level, renewable energy consumption adoption, or resource wealth as simple routes to better health outcomes, this study demonstrates that their impacts are conditional, generally modest, and can even be counterproductive without strong institutions and inclusive development policies. By contrast, financial development consistently stands out as a reliable and increasingly important driver of improvements in life expectancy, indicating that promoting financial inclusion and strengthening financial systems is crucial for achieving lasting public health gains in the E7 countries.

The results also show that the links between economic factors and life expectancy vary across countries and stages of development. This underscores the importance of future research employing more flexible and nuanced analytical approaches that account for institutional quality, income distribution, and healthcare system performance as key moderating factors in understanding the economic drivers of life expectancy.

Drawing on the empirical findings, several policy recommendations are offered to support higher life expectancy and sustainable development in the E7 countries.

First, enhancing financial development should be a core priority. Governments need to expand access to financial services, promote financial inclusion, and establish strong regulatory frameworks that encourage savings, investment, and credit growth. An effective financial system can channel resources into healthcare, education, and social protection key areas essential for raising life expectancy.

Second, while economic growth remains vital, growth strategies should be inclusive and human centered. Investments should target sectors that directly enhance human capital, such as healthcare, education, and social welfare programs. Without simultaneous investment in these social sectors, the health benefits of economic progress may remain limited.

Third, promoting renewable energy consumption must be paired with equitable and sustainable implementation. Renewable energy policies should ensure that new technologies contribute to public health improvements while minimizing environmental and social risks.

Fourth, the consistently negative effect of natural resource dependence highlights the urgency of resource governance reforms. E7 countries should diversify their economies, invest in value-added industries, and strengthen institutional capacity to ensure that resource revenues are used transparently and effectively. Evidence suggests that corruption and weak governance undermine environmental regulations and sustainable energy transitions (17). Establishing transparent, low-corruption, and accountable institutions is therefore a prerequisite for ensuring that natural resource benefits translate into improvements in human welfare.

Finally, the findings underscore the importance of social infrastructure, particularly adult literacy and access to clean water in shaping health outcomes. Expanding access to education and safe water is not only cost-effective but also foundational for achieving health equity and sustainable development. For E7 countries, prioritizing these social determinants can amplify the benefits of economic growth, financial development, and resource management, while reducing health disparities.

In conclusion, E7 countries should adopt an integrated development strategy that strengthens financial systems, fosters inclusive and sustainable economic growth, supports renewable energy transitions, reforms resource governance, and invests in social infrastructure. Such a comprehensive approach is essential to ensure that economic and environmental progress translates into sustained increases in life expectancy and overall well-being.

This study is subject to several limitations. It relies on secondary data sources, which may introduce measurement errors and inconsistencies across countries and overtime. Although econometric methods were applied to mitigate these concerns, data quality could still influence the robustness of the findings. The analysis also focuses on a limited set of determinants economic levels, renewable energy consumption, financial development inflows, and natural resource rents while excluding other important factors such as healthcare spending, education quality, and social policies that may shape life expectancy outcomes. Furthermore, the assumption of linear relationships among variables may overlook potential non-linear dynamics or interactions. Although the MMQR approach effectively addresses unobserved heterogeneity across quantiles, it does not fully resolve the issue of endogeneity, particularly the bidirectional relationship between economic development and health outcomes. Future research could employ instrumental variables (IV) or dynamic panel approaches such as generalized method of moments (GMM) to strengthen causal inference. Additionally, while governance quality is theoretically important in mediating the relationship between natural resources and health, this study does not explicitly incorporate governance indicators due to data constraints; their inclusion in future work would enrich the analysis. Additionally, this study does not explicitly incorporate governance quality indicators—a notable limitation. Future research should address this by integrating measures of corruption and bureaucratic inefficiency, as emerging evidence confirms their critical influence on sustainable development pathways. For instance, Xu et al. (17) demonstrate that corruption-related risks undermine the effectiveness of environmental regulations and the success of green electricity transitions, suggesting that governance quality is essential for improving health and development outcomes.

Future studies could broaden the scope by testing non-linear relationships through advanced modeling techniques, such as machine learning or polynomial regression. Expanding the set of macroeconomic and microeconomic determinants such as healthcare infrastructure, education quality, or political stability would also provide a more comprehensive understanding of life expectancy outcomes. Investigating interaction effects, for instance between renewable energy consumption and financial development or resource rents, could yield valuable insights for maximizing benefits while minimizing drawbacks. Moreover, country-specific case studies and longitudinal analyses would refine policy recommendations by capturing long-term dynamics and national heterogeneity within the E7. Such extensions would advance the evidence base for designing more precise and inclusive health and development policies.

This research advances the literature by moving beyond mean-based analyses and uncovering how the determinants of health outcomes differ across the life expectancy distribution. By applying the MMQR approach, the study provides fresh evidence that health inequalities are not uniform; rather, economic development, financial growth, renewable energy, and resource use exert distinct effects at lower and higher levels of life expectancy. Such heterogeneity underscores the importance of tailored policy responses and demonstrates that addressing health disparities requires more than average-level solutions. This study investigated the heterogeneous effects of economic level (ECL), renewable energy consumption (REC), financial development (FDI), and natural resource rents (NRR) on life expectancy at birth (LEX) across different quantiles in the E7 economies using the Method of Moments Quantile Regression (MMQR) technique. The findings highlight substantial variation in how these factors affect LEX at different stages of development. Both ECL and REC have positive impacts on LEX across all quantiles, though their effects are relatively modest and exhibit diminishing returns at higher life expectancy levels. In contrast, FDI consistently shows a strong and increasing positive influence on LEX, underscoring the essential role of a well-developed financial sector in enhancing health outcomes and living standards in emerging economies. Conversely, NRR maintains a consistently negative relationship with life expectancy, indicating that dependence on natural resource rents creates structural barriers to achieving sustained improvements in public health.

Overall, the results indicate that although economic level and renewable energy consumption adoption are important contributors, they alone are insufficient to achieve substantial improvements in life expectancy. Financial development stands out as a stronger and more consistent driver of public health progress in the E7 economies, whereas mismanagement or excessive dependence on natural resource rents continues to hinder these gains. Tackling these challenges calls for integrated policy approaches that emphasize financial sector development, sustainable resource governance, and investments in social infrastructure to ensure that economic advances effectively translate into better health outcomes.