Social Stratification and the Formation of Single Parent Household in Japan

It has been confirmed that the children who grew up in a single parenthood had many disadvantages both on educational attainment and the life course afterwards. This finding is robust  in US, but recently Japanese studies have also found it repeatedly in Japan. This is to say that parental divorce limit their children’s life chance, and hence reduce their children’s intergenerational social mobility.

 If we have concern with the intergenerational reproduction of poverty (or social stratification), we have to clarify the relationship between social attributes and the occurrence of the single parent households. We use the data of Longitudinal Survey of Newborns in the 21st Century (2001 Cohort) by Ministry of Health, Labour and Welfare of Japan. Respondent were randomly selected from men and women who nurture kids born either between at January 10th and 17^th in 2001 or at between 10^th and 17^th in July 2001. Initial survey was done in 2002 and the sample size was 47,015. Afterwards, panel survey has been done for every year, except for 2007.

We set household composition at 9^th survey (conducted in 2010) as basic dependent variable. As sample attrition was serious, we dealt with this sample selection bias by propensity score analysis and Heckman’s two stage estimation probit model (Heckit). We found that those who did not have college or university degree, those who had married at early ages, and those who had low  household income in 2002 tended to drop out from subsequent survey, but they also tended to divorce and form a single parent household in 2010. Marital relationships of those at low socioeconomic status were generally insecure and were likely to disrupt.

These findings suggest the mediating effect of divorce between parents’ low educational attainment and those of their children’s.