Expert-based and selected endogenous weighting in composite indicators: evidence from the cultural and creative cities index
摘要
The choice of weighting scheme is one of the most consequential decisions in the construction of composite indicators, yet applied evidence that systematically compares weighting schemes of different natures remains limited. This paper addresses this gap using the European Commission’s Cultural and Creative Cities Index (IC3) as a case study. In our case, we compare the official index of the European Commission, based on subjective weights derived from expert judgment, with three alternative reconstructions based on endogenous methods reflecting different methodological logics: Principal Component Analysis (PCA), Data Envelopment Analysis (DEA), and the Distance P2 (DP2). The analysis focuses primarily on two dimensions of comparison: the robustness of city rankings and changes in the way the indicator synthesizes the underlying information. As a complementary exercise, we incorporate an illustrative regression based on the DP2 reconstruction in order to show how different aggregation decisions may translate into subsequent empirical interpretation. The results show a high overall concordance between the official index and the alternative reconstructions, suggesting that city rankings are, in general terms, robust to changes in weighting. However, this ordinal stability does not imply substantive equivalence. The different methodologies generate variations in the relative contribution of the dimensions and, therefore, in the analytical interpretation of the phenomenon. Overall, the paper contributes to the methodological debate by showing that endogenous weighting methods can provide reproducible and transparent alternatives to expert judgment, while highlighting the interpretative implications of replacing normative weights with data-driven rules.