Enhancing transparency in circular economy assessment: A fuzzy distance-based multi-criteria framework

The growing importance of the circular economy has underscored the need for reliable measurement frameworks that not only track progress but also enhance the transparency and credibility of environmental policies. Robust composite indicators are essential to integrate diverse dimensions of circularity into a single, comparable metric, enabling policymakers to assess performance and communicate results effectively. Nevertheless, assessing circular economy outcomes is hindered by data limitations, since information on material flows, recycling rates, and circular material use often suffers from inconsistencies, incomplete records, and subjective evaluations. To address this uncertainty, we propose a novel framework that represents each performance indicator as a Triangular Neutrosophic fuzzy number (TNN), capturing both quantitative variability and linguistic assessments. A new fuzzy distance measure is defined to quantify three established multi-criteria methods. Unlike conventional score-based approaches, this model preserves inherent ambiguity by directly applying distance metrics, yielding a more accurate representation of each country’s circular performance. The empirical analysis of EU member states shows a high degree of agreement across methods, consistently identifying the Netherlands, Germany, Italy, and Belgium as the top-performing countries. Sensitivity analysis confirms the stability of these rankings under alternative weighting schemes. In addition, the proposed Possibilistic Hamming distance improves the representation of uncertainty compared to traditional approaches. Overall, the proposed framework offers a transparent and robust tool for evaluating circular economy performance, supporting more informed policy design and sustainability strategies.