Unveiling the spillover effects of democracy and renewable energy consumption on the environmental quality of BRICS countries: A new insight from different quantile regression approaches

This research explores the nexus of economic expansion, population, use of renewable energy, democracy, and the combined effect of democracy and GDP on carbon dioxide (CO₂) emissions in the BRICS countries. We apply an extended STIRPAT model, including the variables of democracy and democracy with GDP, to examine the case of the BRICS countries between 1990 and 2019. Quantile regression methods (Simultaneous, Powell, and MM-QR) are applied together with the Dynamic OLS (DOLS), Fully modified OLS (FMOLS), and CCR. The results indicate that economic size (GDP) and population are linked to increasing levels of CO₂. Whereas increased use of renewable sources of energy can help reduce environmental degradation. Similarly, an interaction between good democracy and economic growth is helpful for a sustainable environment. The Dumitrescu and Hurlin panel causality test highlights a bidirectional causal link between GDP, Democracy, and Population with CO₂, but only a unidirectional causal relationship between renewable energy and CO₂. Policymakers in the BRICS countries need to consider:1) pro-growth economic policies along with better democratic practices, 2) higher promotion of renewable energy resources, and 3) improving living standards for the population to achieve higher environmental quality.