Abstract This paper analyzes the implications of the interrelationships (linkages) between the Sustainable Development Goals (SDGs) for measuring sustainability, using a synthetic indicator based on the distance P2. This indicator solves several problematic aspects of aggregating data, such as the choice of weightings and the existence of interrelationships, and verifies the mathematical properties necessary to be a rigorous measure. An extensive database is used that collects the sustainable development index and the seventeen SDGs of one hundred and ten countries during the period 2000–2023. As a starting point, the existence of important interrelationships between the SDGs that justify adopting the P2 distance is established. The analysis reveals notable differences between the statistical distributions of the indicator based on the P2 distance and the sustainable development index of the United Nations Development Programme (UNDP) and that, from the point of view of the P2 distance, the UNDP index overestimates the sustainability of the countries with the greatest advances and underestimates that of the countries with the greatest lag due to its weighting scheme, which is based on equal weights. In contrast, the P2 distance gives more importance to environmental goals and the SDG17 (partnerships). The composition of the distance P2, as well as other aspects derived from its methodology, has significant implications in the orientation of measures to improve sustainability. Additionally, the convergence analysis with both indicators shows that the convergence results depend crucially on the indicator used and that the level of income is a relevant differential factor for evaluating convergence.
Abellán-Salinas et al. (2026) studied this question.