Part 1. The Complex Nature of Well-being: From Academic Definitions to Policy Programmes -- Chapter 1. The Notion of Well-being Across Contexts and Countries (Gary Pollock) -- Chapter 2. Child and Youth Well-Being on the European Political Agenda (Britta Busse) -- Chapter 3. A Comparative Expert Survey on Measuring and Enhancing Well-being in Europe (Jessica Ozan) -- Chapter 4. Conceptions of Well-being and Differences Among Children and Young People in Europe (Alexandros Sakellariou) -- Part 2. Measuring Children and Young People's Well-being -- Chapter 5. Strengths and Shortcomings of Survey of Children and Young People Well-being (Haridhan Goswami) -- Chapter 6. Longitudinal Research on Children and Young People in Europe and Beyond (Britta Busse) -- Chapter 7. Current Attempts to Measure Children and Young People Well-being (Zsuzsa Szántó) -- Chapter 8. How to Develop Well-being Survey Questions for Young Children: Lessons Learned from Cross-cultural Cognitive Interviews (Renata Franc) -- Part 3. Possibilities for Further Research -- Chapter 9. Challenges in Conducting a New Longitudinal Study on Children and Young People Well-being in European Union (Gary Pollock) -- Chapter 10. Strategies and Methodological Challenges for Involving Children and Young People in a Research on Wellbeing (Mariona Ferrer-Fons) -- Chapter 11. With a View Towards the Future: Different Options to Measure the Well-being of Children and Young People Across Europe longitudinally (Jessica Ozan) -- Chapter 12. The Potential Policy Benefits of Measuring Child Wellbeing Across Europe (Chris O'Leary).