Question

n a 2011 NY Times Editorial, Ross Douthat looks at the work of Amartya Sen and discusses how the "100 million missing women" has now increased to "160 million." He laments that the increase continues to demonstrate COMPLETELY the level of misogyny and the availability of abortions throughout the world. Based on your understanding of Emily Oster's research (discussed by Dubner and Levitt), what other alternate explanation(s) is/are there for some of these "missing women"?

Answer 1

Emily Oster's Research:

In many Asian countries the ratio of male to female population is higher than in the West: as high as 1.07 in China and India, and even higher in Pakistan. It is suggested that this imbalance reflects excess female mortality and have argued that as many as 100 million women are “missing.” We have an explanation for some of the observed overrepresentation of men: the hepatitis B virus. There is new evidence, consistent with an existing scientific literature, that carriers of the hepatitis B virus have offspring sex ratios around 1.50 boys for each girl. This evidence includes both cross‐country analyses and a natural experiment based on recent vaccination campaigns. Hepatitis B is common in many Asian countries, especially China, where some 10–15 percent of the population is infected. Using data on prevalence of the virus by country and estimates of the effect of hepatitis on the sex ratio, We can say that hepatitis B can account for about 45 percent of the “missing women”: around 75 percent in China, between 20 and 50 percent in Egypt and western Asia, and under 20 percent in India, Bangladesh, Pakistan, and Nepal.

However we should know that Oster’s work stirred debate for a few years in the epidemiological literature, but eventually she admitted that the subject-matter experts had been right all along. One of Das Gupta’s many convincing counterpoints was a graph showing that in Taiwan, the ratio of boys to girls was near the natural rate for first and second babies (106:100) but not for third babies (112:100); this pattern held up with or without hepatitis B.

In a follow-up blog post, Levitt applauded Oster for bravery in admitting her mistake.