In the first evaluation of loneliness measurement across all 27 EU countries, Annecy Behavioral Science Lab grades the tools behind billion-euro policy — and releases a traffic-light system to tell reliable measures from weak ones.
Annecy, France, July 31, 2026 — Europe is pouring billions into tackling loneliness — Spain alone estimates it costs over €14 billion a year — yet of the survey questions governments use to measure it, only one produces scores that can be reliably compared from one EU country to the next. And that measure, new research shows, captures emotional distress more than the lack of social connection that policies are meant to fix.
That is the central finding of an evaluation of loneliness measurement across all 27 EU member states (25,646 respondents), released today by Annecy Behavioral Science Lab (ABSL) in two policy briefs. The underlying evaluation was conducted by ABSL with the European Commission’s Joint Research Centre (JRC) and is published in the peer-reviewed journal Collabra: Psychology. ABSL led the two briefs, produced under the European Union’s Horizon Europe LONELY-EU project.
Without measures that can be trusted, the briefs warn, interventions can look effective when they are not, estimates for the same population can diverge sharply, and vulnerable groups can go uncounted; and there is no dependable way to tell whether loneliness across Europe is rising or falling.
A traffic light for loneliness data
To help governments tell a reliable measure from a weak one, ABSL is releasing a traffic-light rating system that grades each instrument green, yellow or red on three dimensions: whether scores can be meaningfully compared across EU countries (cross-EU comparability), whether the measure captures loneliness rather than related states such as depression (construct validity), and whether it reflects the full range of lonely experiences (content coverage). The verdict? No measure in use today scores green on all three.
“A loneliness figure is only as good as the instrument behind it. Right now Europe is making billion-euro decisions on numbers that often can’t be compared between countries, or that measure the wrong thing. This rating lets policymakers see how much weight a given measure can bear, before they act.” – Dr Hans Rocha IJzerman, Director of the Annecy Behavioral Science Lab and Associate Researcher, University of Oxford
Good measures need infrastructure behind them
Even the strongest questionnaire cannot deliver a trustworthy European picture on its own, the briefs argue: it needs the surrounding infrastructure such as coordinated annual data collection, quality assurance, and integration with Eurostat similarly to how the EU already tracks employment, health and education.
“Tackling loneliness isn’t just about monitoring low mood. If a measure misses the people whose social disconnection and isolation is driven by structural issues, policy will miss them too.” – Dr Miguel Silan, Annecy Behavioral Science Lab
ABSL is developing the EU SIL Index (expected 2026–2027), a new measure designed to score well on all three dimensions. It is being built to be modular: a common core that keeps countries comparable, plus components adapted to how social connection more generally is experienced by specific groups (e.g., older people in rural areas, young adults, migrants) so that comparability does not come at the cost of missing the populations most at risk. Like any measure, it will receive independent validation before implementation.
Key findings
- Only the Three-Item UCLA Loneliness Scale (T-ILS) compares reliably across all 27 countries but it captures emotional distress more than gaps in social connection, the dimension most interventions target.
- No existing measure earns a green rating on all three quality dimensions. The De Jong Gierveld scale has the strongest content coverage but reliably compares across only a handful of countries; the widely used single-item question fails validity thresholds in 8 countries.
- Measurement choices change the picture dramatically. Different surveys produced loneliness estimates diverging by up to 8 percentage points within the same EU country in a single year — and by 20 points across two US reports in 2025.
What ABSL recommends
Standardise on the T-ILS today while being open about what it captures; lobby to embed validated measures into established European surveys such as the European Social Survey; and begin infrastructure planning now with Eurostat and national statistical offices. That investment, the briefs argue, should sit alongside the EU’s existing statistical monitoring.
Over time, the briefs call for the rating system to become a shared quality standard, an accreditation for the measures behind official loneliness statistics, so governments can show that the numbers driving policy meet an agreed bar. ABSL, which developed the framework, is advocating for such a standard and can support national statistical offices in applying it.
Resources
- Policy Brief No. 3 — Europe’s Loneliness Measurement Challenge: Building Evidence-Based Infrastructure
- Policy Brief No. 4 — The LONELY-EU Evidence Quality Rating System
- Peer-reviewed study — Paris et al. (2026), Evaluating Loneliness Measurements Across the European Union, Collabra: Psychology
- About ABSL and the LONELY-EU project: lonelinessineurope.eu · absl.io
Get involved
● Join the LONELY-EU network by taking the survey — open to everyone with lived experience of social connection or loneliness, across every EU member state. Researchers can use the technical version (access code for both: LONE2A).
● Subscribe to the ABSL newsletter
● Follow ABSL on LinkedIn
About
Annecy Behavioral Science Lab (ABSL) is an independent research organisation specialising in the measurement and psychometrics of psychological and social phenomena, and advising governments and statistical bodies on the quality of the data behind policy. ABSL led the loneliness-measurement research described here.
The work was completed under LONELY-EU, a Horizon Europe project set up to sharpen how Europe understands, tracks and makes policy on social isolation and loneliness. The consortium is coordinated by Prof. Maike Luhmann (Ruhr University Bochum) and includes scientific and policy leads at Università Cattolica del Sacro Cuore, the University of Milan, SWPS University, Vrije Universiteit Amsterdam, and ABSL.
This work is supported by the European Union’s LONELY-EU project (Grant Number: 101177225). Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them.
Media contact
Dr Miguel Silan, Annecy Behavioral Science Lab – migs@absl.io
