Inequality of opportunity in a land of equal opportunities: The impact of parents’ health and wealth on their offspring’s quality of life in Norway

BACKGROUND: The literature on Inequality of opportunity (IOp) in health distinguishes between circumstances that lie outside of own control vs. efforts that – to varying extents – are within one’s control. From the perspective of IOp, this paper aims to explain variations in individuals’ health-related quality of life (HRQoL) by focusing on two separate sets of variables that clearly lie outside of own control: Parents’ health is measured by their experience of somatic diseases, psychological problems and any substance abuse, while parents’ wealth is indicated by childhood financial conditions (CFC). We further include own educational attainment which may represent a circumstance, or an effort, and examine associations of IOp for different health outcomes. HRQoL are measured by EQ-5D-5L utility scores, as well as the probability of reporting limitations on specific HRQoL-dimensions (mobility, self-care, usual-activities, pain & discomfort, and anxiety and depression). METHOD: We use unique survey data (N = 20,150) from the egalitarian country of Norway to investigate if differences in circumstances produce unfair inequalities in health. We estimate cross-sectional regression models which include age and sex as covariates. We estimate two model specifications. The first represents a narrow IOp by estimating the contributions of parents’ health and wealth on HRQoL, while the second includes own education and thus represents a broader IOp, alternatively it provides a comparison of the relative contributions of an effort variable and the two sets of circumstance variables. RESULTS: We find strong associations between the circumstance variables and HRQoL. A more detailed examination showed particularly strong associations between parental psychological problems and respondents’ anxiety and depression. Our Shapley decomposition analysis suggests that parents’ health and wealth are each as important as own educational attainment for explaining inequalities in adult HRQoL. CONCLUSION: We provide evidence for the presence of the lasting effect of early life circumstances on adult health that persists even in one of the most egalitarian countries in the world. This suggests that there may be an upper limit to how much a generous welfare state can contribute to equal opportunities. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-14084-x.