Parts of Asia have subtantially more males in the population than females. Male to female sex ratios are about 1.07 in China, 1.08 in India and 1.11 in Pakistan. In the west, male to female sex ratios are generally close to 1. This difference in the sex ratios has generally been attributed to discrimination against the female child, the practice of female feticide (or sex-selective abortion) and female infanticide.
Emily Roster, a post-doctoral scholar at Harvard has just released a landmark study on the issue which points part of the blame at the prevalence of hepatitis B, which boosts the likelihood of a male child being born by almost fifty percent. The much higher rates of the infection in China mean that nearly 70% of the imbalance in sex ratios can be attributed to hepatitis B while comparatively lower rates of infection mean that the infection only explains less than 20% of the disparity in Pakistan, India and Bangladesh. Roster's findings remain controversial for two reasons: a) scholars have found out that the male/female sex ratio at birth for the first child in China remains close to 1 but increases to 1.5 for the second and other additional children; b) the sex ratio in Taiwan, which also has a high incidence of hepatitis B, is closer to 1.
Whether hepatitis B turns out to be as large a cause as posited by Roster is somewhat immaterial because Roster's key contribution has been much broader. She has provided fresh insight into looking at an issue that has been bogged down by tired research relying primarily on stereotypes about culture. Her contribution to the field of demographics reminds me of another similar groundbreaking work done by Columbia anthropologist Mahmood Mamdani. In the 1970s, Mamdani wrote a book called The Myth of Population Control: Family, Caste and Class in an Indian Village that explored the economics behind why poor people tend to have more children.
To more open debate!
Ed:LisaM
Article comments
1 - vikk
Interesting subject. I'm curious. Did she say why or how hepatitis causes this problem?
2 - Victor Lana
Very interesting post. The thing I know is this: a colleague and his wife went to China to adopt a baby. All they saw in the orphange were girls. Hundreds of girls.
So, perhaps there is a cause as your post suggests, but I think this is another angle to explore.
I don't know if the same holds true throughout the rest of Asia.
3 - Jessica
The paper mentioned was published by Emily Oster, not Roster!