How many missing women are there really?

Last year I read a fascinating book, Unnatural Selection: Choosing Boys Over Girls, and the Consequences of a World Full of Men, by Mara Hvistendahl. She talks about the issue of missing women, how demographically, there should be more women than there are in many different countries of the world. The issue was the subject of an Economist cover nearly two years ago.

Tyler Cowen has alerted me to a  paper on the subject, soberly entitled, Missing women: age and disease, by Siwan Anderson and Debraj Ray.

The authors, instead of doing a fairly high level comparison of ratios between men and women at birth, and men and women in the population as a whole, look at projections of the relative proportions of men and women given the same relative birth and death ratios between genders that happen in the first world. They readily point out that there are many different ways to work out what the “appropriate” relative birth and death rates are, but nevertheless they come up with some fascinating conclusions.

Our study of excess female deaths by age yields two key findings. First, once we control for natural variations in the sex ratio at birth, sub-Saharan Africa has as many missing women as India and China: significantly more as a percentage of the female population. Second, the majority of missing women are of adult age. Sub-Saharan Africa has no missing females at birth, while the corresponding proportion for India is under 11%. China’s missing females, in contrast, are largely prenatal. About 37–45% of them may be classified as missing at birth. But all these regions display missing women at a variety of ages. For instance, excess female mortality up to age 15 does not account for more than a third of the total in India or sub-Saharan Africa.

So the insight from this study for me is the complexity it adds to the story. While the standard story of why there are “missing women” is sex specific abortion and female infanticide, that is only really the explanation in China. In other countries, the story is much more complex, with relative female death rates much higher than males at a variety of ages, and in sub-Saharan Africa, particularly because of maternal death rates and deaths from HIV-AIDS.

Ultimately, the conclusion of the paper is not that different from the Economist’s attention grabbing “100 million missing women”. But the reasons are far more interesting.

We find approximately 20 million missing women in India, 58 million missing women in China, and 8 million missing women in sub-Saharan Africa. Look at the enormous difference between China and the other two regions (in flows all three regions were about the same). This comes from the fact that excess female deaths in China are clustered at age 0. We reiterate, though, that these estimates must be treated with a great deal of caution.

The missing women in India and sub-Saharan Africa are largely because a variety of causes (injury, suicide, various diseases) disproportionately kill the women there.  That’s a reason to worry, and potentially an easier issue to fix, if the will and the resources are available.