JRC statistical audit of the 2024 European Skills Index

The European Skills Index (ESI) is a multidimensional index that ranks the skills systems of 31 countries (the EU27 countries, Iceland, Norway, Switzerland, and the United Kingdom) based on their performance on the three dimensions of skills development, skills activation and skills matching. The European Commission's Competence Centre on Composite Indicators and Scoreboards (COIN) at the Joint Research Centre (JRC) in Ispra was invited by the index developers to audit the ESI for the third time (Norlen and Saisana 2018; Caperna and Becker 2022). JRC-COIN aims to help ensure the transparency of the index methodology and the reliability of its results. This JRC-COIN audit focuses on data quality, the statistical soundness of the multi-level structure of the index, and the impact of key modelling assumptions on the results. The analysis suggests that meaningful inferences from the index with special attention on countries with close scores can be drawn. The ESI is a reliable tool for ranking the performance of country skills systems with a conceptual framework that is statistically coherent. ESI ranks are shown to be representative of a plurality of scenarios. They are also shown to be robust to changes in the aggregation and imputation methods and the pillar weights, except for a very few cases where ranks should be interpreted with some caution. The ESI is shown to have good statistical properties, but there always exists some room for improvement. To this end, JRC-COIN has made some suggestions towards improving the match between the conceptual framework and the statistical characteristics of the index.