Despite comparable living standards and an extensive healthcare provision, European countries exhibit varying levels population health. While a part of the differences in health can be explained by variation in biological factors, a consistent relationship between socio-economic status and health suggests that population health is strongly affected by the distribution of material, social and behavioural factors within society. This raises both ethical and economic concerns, considering the instrumental role of health in productivity and well-being.Existing literature suggests that population health varies across countries and over time, yet little has been done to try to disentangle socio-economic factors that shape variation in health in a systematic manner. Micro-econometric decomposition methods are often used in income inequality literature in order to examine the sources of such inequalities, yet the applications of these methods to analyse health inequality are more limited. This project aims to fill this gap in order to provide a more detailed explanation on the nature of this variation across countries and over time, with an aim to advise policymakers on ways to target health inequality.The proposed research project is structured as follows: first, it aims to explicitly decompose cross-national variation in self-assessed health status across a number of European countries (including Luxembourg) into driving factors, such as differences in demographics, education, income, labour market and occupational structure; second, it extends the decomposition framework to explore the factors shaping changes in population health in a country affected by a severe economic crisis (Ireland); finally, it explores cross-country variation in health between two European countries with similar levels of development but different institutions (Germany and the UK). The goal of this project is to provide empirical evidence for policymakers as well as to contribute to the development of theory on social determinants of population health and cross-country health inequality.