From missing data to meaningful rankings: Multi-criteria performance evaluation of six global iron ore producers

This paper develops a two-step framework to benchmark the financial and environmental performance of the six largest global iron ore producers - Vale, BHP, Rio Tinto, Anglo American, Fortescue Metals Group, and Glencore - over the period 2009-2024. We first apply a novel anisotropic diffusion-based method, to complete and denoise missing emissions data (scopes 1-3) in the MCDM matrix, while preserving firm- and year-specific structure. We then use an optimized polar decomposition approach into the MCDM matrix obtained from the first stage, to derive consensus rankings across TOPSIS, VIKOR, and COPRAS under three decision scenarios: trade-off dominance, criteria-importance dominance, and balanced performance. Results show that financial indicators (operating profit, gross profit, EBITDA, revenue) dominate the consensus weights, but Scope 1 and 2 emissions consistently appear among the top trade-off pairs, suggesting that direct and energy-related emissions are becoming structurally embedded in performance assessments. Temporal analysis reveals a gradual improvement in overall performance, with BHP, Rio Tinto, and Fortescue consolidating leadership positions, while Vale, Anglo American, and Glencore are lagging behind. The findings highlight that the iron ore sector remains in a "financial primacy" regime but that integration of decarbonization efforts into asset and capital planning is emerging as a key differentiator. The proposed methodology provides a replicable framework for small-N benchmarking under incomplete and noisy GHG data conditions and offers actionable insights for academic, investors, and policymakers.