Explaining immigrant-native differences in health at birth: The role of immigrant selectivity in Spain

A vast literature finds that immigrants have better health than natives, despite being socio-economically disadvantaged – the so-called “Immigrant Health Paradox” (IHP). A key question is whether and how this advantage is passed on to their children, especially in Europe where the research is less developed and conclusive. Moreover, theoretical explanations for the IHP are rarely empirically verified. This includes the popular “selectivity hypothesis”, according to which immigrants are healthier because positively selected at origin in terms of health or socio-economic status (SES). Using 2007-2019 Spanish birth registries, we investigate immigrant-native gaps in health at birth (birth weight and gestational age) and whether they are explained by immigrants’ educational selectivity. We find that immigrants are less likely to deliver low birth weight (LBW) children, but are disadvantaged in terms of macrosomia and gestational age. Selectivity is associated with reduced LBW also net of parental SES, which explains the lower risk of LBW children among immigrants and especially those from Northern Africa and Latin America. Nevertheless, some groups have higher LBW risks despite being positively selected, and educational selectivity is not associated with macrosomia and gestational age. We confirm the selectivity hypothesis but question its universality across groups and health outcomes.