Patrilineality, Son Preference, and Sex Selection in South Korea and Vietnam

Recent advances in promoting the rights of women and girls globally have been partially offset by increasing implementation of son preference through offspring sex selection, leading to rising sex ratios at birth1 (SRB) and child sex ratios throughout Asia, as well as parts of Eastern Europe and Africa. The past two decades have seen the number of countries with high child sex ratios increase from five to nineteen (Hudson and den Boer 2015). In recent history, only one country has reduced its sex ratio at birth from extremely high levels to biologically normal levels: South Korea, from a peak of 116.5 males per 100 females in 1990 to 106.2 in 2007. While South Korea's sex ratio at birth was declining throughout the early to mid 2000s, the sex ratio at birth in another Asian country, Vietnam, began an erratic rise, reaching 113.8 in 2013 (see Figure 1). How can we explain this recent rise in Vietnam's sex ratio, and are there lessons for Vietnam, or for other countries facing high sex ratios at birth, from the experience of South Korea?