Financial access, renewable energy, environmental quality, and health outcomes: mechanism evidence from BRICS countries

Despite growing interest in sustainable finance, empirical evidence on how financial access relates simultaneously to environmental quality and public health remains limited, particularly in large emerging economies. This study investigates the associations between financial access, environmental quality indicators, and health outcomes in BRICS countries over the period 2001–2023, with particular attention to the mechanisms linking environment and health. Financial access is proxied by commercial bank branches per 100,000 adults, capturing the institutional reach of the banking system. Panel fixed-effects models combined with mediation analysis are employed to evaluate both direct relationships and indirect environmental pathways. Environmental quality is measured through renewable energy consumption, carbon dioxide emissions, and PM2.5 air pollution, while health outcomes are represented by infant and under-five mortality rates. The empirical models control for GDP per capita and its squared term to capture potential non-linear income–environment relationships, government expenditure (GOV), energy consumption share, and urban population share to account for macroeconomic and demographic influences. The framework is grounded in Financial Development Theory, the Environmental Kuznets Curve hypothesis, and the Porter Hypothesis. Results show that greater financial access is significantly associated with higher renewable energy use and lower carbon emissions and PM2.5 concentrations. Expanded financial access is also linked to significant reductions in infant and under-five mortality. Mediation analysis indicates that improvements in environmental quality partially transmit the health benefits of financial access, confirming an environmental–health pathway. Robustness checks using alternative financial access measures support the stability of the findings. Overall, the study underscores financial access as a key policy lever for enhancing environmental sustainability and public health in emerging economies.