Developing and Evaluating a Composite Index of Country Sustainability Profiles: A Multivariate Framework Complementing GDP

Cross-country sustainability assessment requires transparent integration of economic, social, and environmental information, yet composite measures are sensitive to normalization, weighting, and aggregation choices. This study developed and evaluated a composite sustainability-profile index for 174 countries using 15 World Development Indicators averaged over 2010–2019. First, the indicators were transformed, directionally oriented, min–max scaled, and aggregated into three equally weighted pillars, with GDP assigned 50% of the economic-pillar weight. Next, robustness was evaluated through Spearman correlations with equal-weight, no-GDP, and geometric-aggregation alternatives, leave-one-indicator-out analysis, k-means stability checks, and rotated principal component analysis. The results showed a positive economic–social association (0.76) and a negative economic–environmental-pressure association (−0.47). Moreover, alternative rankings were strongly correlated with the baseline (0.939–0.977), retained nine of its top ten countries, and produced mean absolute rank shifts of 8.3–12.6 places. Leave-one-indicator-out correlations ranged from 0.940 to 0.998, whereas cluster membership showed only moderate stability under alternative scaling (adjusted Rand index = 0.475–0.503); three rotated components explained 63.0% of indicator variance. Overall, the index was robust for broad comparative profiling but not for treating individual ranks or country groups as invariant. It should therefore be reported with pillar scores and sensitivity evidence rather than interpreted as a definitive national sustainability ranking.