New results on the missing women question

This paper (pdf) came out about two years ago, by Siwan Anderson and Debraj Ray, in the highly esteemed Review of Economic Studies, yet I haven’t seen it discussed in the blogosphere, so here goes:

Relative to developed countries and some parts of the developing world, most notably sub-Saharan Africa, there are far fewer women than men in India and China. It has been argued that as many as a 100 million women could be missing. The possibility of gender bias at birth and the mistreatment of young girls are widely regarded as key explanations. We provide a decomposition of these missing women by age and cause of death. While we do not dispute the existence of severe gender bias at young ages, our computations yield some striking new findings: (1) the vast majority of missing women in India and a significant proportion of those in China are of adult age; (2) as a proportion of the total female population, the number of missing women is largest in sub-Saharan Africa, and the absolute numbers are comparable to those for India and China; (3) almost all the missing women stem from disease-by-disease comparisons and not from the changing composition of disease, as described by the epidemiological transition. Finally, using historical data, we argue that a comparable proportion of women was missing at the start of the 20th century in the United States, just as they are in India, China, and sub-Saharan Africa today.

That is a very different interpretation from what one usually hears.


"Son Preference and the Persistence of Culture: Evidence from Asian Immigrants to Canada" by Doug Almond shows that even in first world nations with universal health care the gender ratio is economically and statistically different from the expected 1.05 for Asians and quite different from the native population.

100M single men with no prospect of marriage makes for a pretty scary military.

Big countries have big needs (like big police forces and militaries); the relative values are what matter. Personally, I'm more optimistic about China's future: if it's already surviving 'peak men' and America survived something similar, that suggests I have overestimated the danger of the demographic imbalances.

....or an impending homosexual revolution.


Are you homophobic?

You will be...

you will be...

Rick Santorum finds your comments fascinating and would like to receive copies of your literature.

It doesn't seem like a different interpretation, just an additional related finding. They don't appear to be contradicting the observation that in recent years births are strongly biased in favour of male children, but I guess is not surprising that as the ability to do this without resorting to murder is only quite recent, it hasn't fed through into a big effect on the overall population just yet.

Interesting paper. Some parts are consistent with the interpretation we normally hear: "close to 44% of China’s missing women are
located “around birth”" (p. 1276). But there are many surprises as well. I'd like to also see analysis of South Korea.

It would be nice to see changes over time in various countries, although there probably isn't reliable data. For example, I would expect more missing young girls (say, ages 1 to 10) in China during the Great Leap than during the Cultural Revolution.

Recent? These results are 2 years old, and miss data from the latest Indian census which clearly shows that sex ratio under 5 years old is worse than for adults.

so invest in brothels

Finally, using historical data, we argue that a comparable proportion of women was missing at the start of the 20th century in the United States.

Wait, but didn't the US have a gender ratio disparity because of the Civil War?

Please disregard this statement.

Benny: Very likely.

Which is meaningful for discussion of causes, but less important if we are concerned (see notkevin and gwern above) with effects of such an imbalance.

Didn't war used to take care of this imbalance problem?

Could this just be a case of faulty statistics?

Benny: the civil war would have made men missing, not women.

Ooops. My mistake. I see a poster further down gives an accurate explanation.

100M single men with no prospect of marriage makes for a pretty scary military.

Some argue that de facto polygamy is producing the same result in the United States.

I remember seeing a BBC documentary about India from 20-30 years ago about the use of ultrasounds to detect female foetuses for selective abortion. It was a thriving free market practice. Later, I believe, India banned such practices (wikipedia says 1994).

So I am not surprised that India has more missing adult women.

It's hard to believe that cardiovascular disease and infectious diseases selectively effect women in India over men unless it's about access to health care rather than the diseases themselves.

The USA was an immigrant country - men from other countries would go first, leaving their family to follow when they had set themselves up. That's a totally diferent scenario to India.

That's a good point mpledger. In the 1900 U.S. men's case, the men at least chose to be in such a skewed country. I think that is a tremendous psychological difference over men being in such a skewed country through no choice of their own.

> men from other countries would go first, leaving their family to follow when they had set themselves up

Immigration was an option for a single man with few family prospects, but less so for a woman.Often, the plan was not for the family to follow, but for the men to work temporarily in the US, move home and buy a farm with what they saved up. For at least a couple of my ancestors, this plan succeeded, but I also know about people (in-law great/granduncles in my case) who stayed, or simply disappeared in the attempt.

I think the data shown in the paper is talking about the ages at which excess death occurs, not a snapshot of the age distribution of missing females today. That's how I've interpreted it here with this graph ( anyway. So I don't think it makes the case that selective abortion from +20 yrs ago causes fewer adult women today (although that follows), rather it's analysing why adult women are dying today.

How do they square their results with this data from China (as reported in the New England Journal of Medicine):

Since the onset of the one-child policy, there has been a steady increase in the reported sex ratio, from 1.06 in 1979, to 1.11 in 1988, to 1.17 in 2001.19 There are marked and well-documented local differences, with ratios of up to 1.3 in rural Anhui, Guangdong, and Qinghai provinces. Data from the 2001 National Family Planning and Reproductive Health Survey, which was carried out among a nationally representative sample of 39,600 women of reproductive age and is the most recent large-scale survey of reproductive health and fertility, show clearly that the increased sex ratio is not confined predominantly to rural China, as has been previously assumed. There is a marked gradient across birth order: in rural areas, the sex ratio for the first birth is 1.05 (within normal limits), but it rises steeply with birth order. In urban areas, the sex ratio is 1.13 for the first birth and peaks at 1.30 for the second birth but decreases for the third and fourth births (which are rare in urban areas).

The sex ratio is more skewed in urban areas than in rural areas, increased from normal levels shortly after the One Child policy and is more skewed still when considering second- or third-born children compared to first-born. What disease could account for this pattern?

I was intruiged by the claims about the United States so I looked at the 1900 census and downloaded the report on the proportion of the sexes.

This report provides the sex ratio for native-born whites between 1850 and 1900 on page 23 of this report -- it ranges between 1.02 and 1.03 except in 1870 where it is 1.01. This almost certainly reflects deaths from the Civil War as noted above. The sex ratio of the overall population of the continental U.S. was higher at 1.04 to 1.05 but this almost certainly reflects the effects of immigration. Europe at the same time had a slight excess of women so it is reasonable to think that the Americas and Australia were siphoning off a disproportionate number of males from Europe.

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