Evaluating Carbon and Energy Taxation Performance in BRICS-T Countries: An Integrated WENSLO-MCRAT Approach

As global climate mitigation efforts intensify, carbon taxation has become a crucial policy tool to curb emissions and enhance fiscal-environmental sustainability. This study assesses the carbon and energy taxation performance of BRICS-T countries (Brazil, Russia, India, China, South Africa, and Turkey) using an integrated multi-criteria decision-making (MCDM) model combining WENSLO (Weights by ENvelope and SLOpe) and MCRAT (Multiple Criteria Ranking by Alternative Trace). Five indicators—Net Effective Carbon Rates (NECR), Net Effective Energy Rates (NEER), Net Energy Tax Revenues and Reform Potential (NETRRP), Revenue Forgone with NECR (RF+NECR), and Shares of Emissions Priced (SEP)—were selected to capture both fiscal intensity and environmental scope. WENSLO was used to derive objective weights, while MCRAT provided performance rankings. Findings indicate South Africa leads in overall performance, followed by India and China, with Brazil and Russia trailing. Sensitivity analysis identifies NECR and SEP as the most influential indicators, significantly impacting rankings. Rank reversal analysis reveals that Turkey’s relative position improves upon the removal of lower-performing countries. The study introduces a robust, data-driven framework for evaluating carbon taxation in emerging economies and offers strategic insights for enhancing climate-aligned fiscal policies.