Sex Ratio at Birth(SRB) Transition and the Diffusion Story: Evidence from South Korea

This study aims to examine the trends in social and geographical variations in SRB in Korea. .The data was taken from “Vital Statistics Birth” for the period from 1981 to 2005. We computed the annual male proportion of live births according to mother’s education, mother’s occupation and geography, demonstrating three year moving average. Logistic regression analysis was employed to estimate the odds ratios of male birth according to social and residential groups. SRB in Korea was more prominent in higher social groups and Seoul dwellers until the early 1980’s, but the ratio reversed to be higher in the less educated, manual-job, and country-living mothers since the late 1980’s. The socioeconomic and geographical gap in SRB was most notable in the early 1990s when the SRB in the country was at its peak, and from the late 1990s onwards, the gap has since narrowed. This unique South Korean phenomenon of a social and geographical reversal pattern in SRB supports the diffusion theory of people adopting medical technology for sex selective abortion, suggesting a model to predict the future trends in countries exhibiting an imbalance in SRB.