Gender imbalance in China: the contribution of Hepatitis B infection

The Search for 100 Million Missing Women - An economics detective story. By Stephen J. Dubner and Steven D. Levitt

Fascinating. There are two fascinating claims here that seem reasonably persuasive:

1. Hepatitis B infection biases live births to male infants. (Hep B infection is very common in some areas of China and used to be very common in Taiwan -- until they began immunizing newborns to prevent perinatal infection.)
2. This phenomena accounts for a significant portion of China's gender bias (too few women -- the other explanations are selective neglect of liveborn girls and selective abortion, the old explanation of 'stopping after the first boy' doesn't work).

Economics and public health are meeting in increasingly interesting ways.