Educational differences in mental health and subjective well-being (SWB) are among the most consistent findings in social epidemiology. In general, lower educated people experience more psychological distress, a higher prevalence of depressive symptoms 1 and less SWB 3-8. Is this the result of selection effects leading more fit individuals toward higher credentials? Although we know that selection processes are present 9 educational attainment remains quite stable after entering the labor market, and hence, during adulthood, acquired schooling is more likely to influence mental health, rather than to result from it 4,10-14. How does a degree of schooling earned during young adulthood translate into better mental health outcomes later in life? One would expect that this core social epidemiological finding has been studied in depth. This is actually not the case. Conventional risk factor epidemiology considers education merely as a control variable or a proxy indicator of, so-called, more relevant, mental health risk behaviors, such as lack of social competence or inadequate stress coping strategies. In the present research proposal we take education more seriously. We understand education as an acquired status of an individual as well as an institution in modern advanced economies and/or credential societies 15 and wonder how in different European countries schooling translates into better mental health and SWB. We are not the first to wonder about the mental health benefits of education. But we go two steps further (a) by studying these mental health benefits in a broad set of European countries; and (b) by developing a macro sociological theory of the impact of the expansion of tertiary education on the mental health of populations. We use several datasets of the European Social Survey (ESS) and depart from a multilevel model both in theory and in methods. At the individual level, we will explore the consequences of education on mental health and SWB from a human capital perspective with special attention to overeducation as a form of person-job misfit. On a societal level, we study the impact of education-labour market misfit and educational
expansion on population mental health.