Modelling Gender Preference: Regional Perspectives on Sex Ratio at Birth in Vietnam

Valentine Becquet, Université Paris Descartes and Institut National d'Études Démographiques (INED)

Vietnam has been facing unbalanced sex ratio at birth since 2006, and the phenomenon is rapidly increasing (112 in 2012). However, important regional disparities exist, partly associated with differences in fertility and prosperity levels. But discrepancies in son preference appear to be the main factor. Thus, this paper aims at modeling fertility behaviors and showing "revealed" preference for sons, through the probability for a woman to have a third child, according to the sex composition of the previous children. Using Kaplan-Meier estimates and Cox regression analyses, it describes regional variations of gender preference, and compares the distinct effects of several characteristics (rural/urban areas, education level, socio-economic status, ethnicity). While Northern Vietnam presents a strong preference for sons, linked to a patriarchal descent system, mixity of offspring is privileged in the South, since cultural mixing of bilateral Khmer and matrilineal Cham people, with Kinh population traditionally patrilineal, developed through centuries.