Changes in child mortality in Korea during the mid-twentieth century: gender, birth order and sibling composition

This study examines the changes in child mortality in Korea during the mid-twentieth century by focusing on gender, birth order and sibling composition. We hypothesize that social practices and biological factors play an important role, but this might differ by gender: while girls enjoyed genetic advantages, boys received more social care. Hence, sex differences in child mortality could reflect the relative strength of these two competing forces. Analyses of individual-level longitudinal data drawn from family registrations in a rural Korean village revealed the following results. First, maternal death increased child mortality substantially, and the association was stronger among boys than girls. Secondly, birth order was positively associated with child mortality, and this association was stronger among boys than girls. Thirdly, sibling size had a non-linear relationship with child mortality, and this association was slightly stronger among girls than boys. Finally, the implications of sibling composition differed by sex: having young siblings increased child mortality among boys and having old siblings reduced it among girls. These findings suggest that the relative strength of social and biological factors depended on the historical context and that Korean families actively responded to their circumstances under these constraints.