LONELY-EU Policy Brief No. 3
Key findings
- A psychometric evaluation of loneliness measures across all 27 EU member states (N=25,646) found that the Three-Item UCLA Loneliness Scale (T-ILS) is the only measure whose scores can be compared across countries.
- In many EU countries, T-ILS scores correlate strongly with emotional states such as depression and happiness but only weakly with social activities, contact frequency, and relationships. An intervention that widens people's social networks may therefore show little change on the T-ILS.
- The Six-Item De Jong Gierveld Scale (DJGLS-6) shows the strongest construct validity, in 25 of 27 EU countries. Its scores can be compared on the same scale (scalar invariance) in only 5 countries.
- Until the EU SIL Index is validated (expected 2026 to 2027), the authors recommend the T-ILS for EU-wide monitoring, with a clear note that it mainly captures emotional distress. They also call for validated loneliness measures in the European Social Survey, the European Values Study, and the International Social Survey Programme.
- Loneliness costs Spain more than €14 billion a year, equal to 1.17% of GDP, according to the Observatorio Estatal de la Soledad No Deseada (2023).
Executive summary
Loneliness costs EU member states billions annually in healthcare and lost productivity, yet comprehensive psychometric evaluation across all 27 EU countries (N=25,646) reveals current measurement instruments vary dramatically in quality¹. The Three-Item UCLA Loneliness Scale (T-ILS) is the only measure achieving crossnational comparability, but primarily captures emotional distress rather than social connection deficits—raising concerns about whether it adequately represents how loneliness manifests across Europe’s diverse populations. Europe urgently needs investment in completing the EU SIL Index (under development, expected 2026- 2027) to achieve both comparability and comprehensive content coverage, alongside systematic measurement infrastructure including annual data collection, quality assurance protocols, and Eurostat integration. Without this evolution, the EU risks basing billion-euro policy decisions on inadequate measures that cannot effectively track whether interventions address the actual drivers of loneliness.
How to cite
Hans Rocha IJzerman, Cristiano Vezzoni, Prakhar Srivastava (2026). Europe's Loneliness Measurement Challenge: Building Evidence-Based Infrastructure. LONELY-EU Policy Brief No. 3 Zenodo. https://doi.org/10.5281/zenodo.18786591
