Missing Women, Hepatitis B, and Sex Ratios at Birth: A Reappraisal of the Evidence

Amar A. Hamoudi, University of Michigan

Counts of "missing women" have been cited as an indicator of reduced women's welfare, especially in several Asian contexts. It has recently been argued that this demographic indicator is confounded by Asia's high prevalence of chronic infection with Hepatitis B Virus (HBV). The medical literature contains empirical evidence that those parents who are chronic carriers of HBV are especially likely to have sons rather than daughters. In recent work, Emily Oster (2005) presented evidence that the relationship was causal, drawing largely on a natural experiment represented by a mass vaccination campaign in Alaska in the mid-1980s. However, I find that analyzing this same event with data from a different source--one which is better suited to addressing the question--produces strikingly different results. My findings may help to ameliorate concerns that age-specific sex ratios and counts of "missing women" are confounded by a HBV-sex of offspring relationship.