Vietnam is a latecomer among countries in Asia recording an excess of male
births. As recently as the beginning of the twenty-first century, the country
had recorded no tangible rise in the sex ratio at birth (SRB)—the number of
males per 100 females—in spite of the many social and demographic features
pointing to latent son preference. Since 2005, the increase in birth masculinity
has been rapid and the proportion of male births is now higher in Vietnam
than in India, a country where the rise in the sex ratio began more than 20
years ago.1
Vietnam’s case raises several questions about the specific factors that
sparked this sudden change, the social context that prompts couples to resort
to sex selection, and the anthropological features that may account for
the heterogeneity in sex preferences across the country. In this article I reexamine
the regional differentials in birth masculinity observed in Vietnam
and the influence of gender bias and local kinship systems, following the
lessons drawn by Monica Das Gupta and colleagues from the experience of
China, India, and South Korea (Das Gupta et al. 2003; Das Gupta 2010). My
objective is to follow the evolution of prenatal sex selection first by testing the
role played by son preference at the province level and then by relating it to
specific dimensions of local kinship systems. This exploration will seek to cast
new light on the cultural patterning of demographic behavior in Vietnam.