Mind the gap: the health advantages that accompany parental marriage vary by maternal nativity

Using data from the UK Millennium Cohort Study (MCS), we examine whether and how the health benefits of having two biological parents in a continuous marital relationship vary by maternal nativity and ethnicity, comparing UK-born White mothers with: (1) White mothers born in wealthy countries; (2) ethnic minority mothers from South Asia; and (3) ethnic minority mothers born in Africa. Making novel use of classification and regression tree (CART) methods, we examine whether marital status is a uniform marker of economic advantage or better health-related behaviours across the four maternal nativity and ethnic groups. The findings, which indicate that the health-related advantages associated with parental marriage are not uniform across the four nativity and ethnic groups, have implications for future research on family gaps in well-being and the socio-economic determinants of health.