[riverdawg]

There is no doubt that feticide, infanticide, and honor killings account for some of the imbalanced gender ratio (males >> females) we observe in many countries. However, there is an interesting hypothesis in the epidemiology literature claiming that this imbalance is due in part (and in some countries, substantially) to the prevalence of hepatitis B, carriers of which are much more likely to have sons than daughters. The exact mechanism for this is not certain, but there seems to be a strong connection to hormonal imbalance at conception that is affected by the hepatitis B virus.

[linda_22003]

I take it you've seen this article from Emily Oster at Harvard, on this subject? http://www.people.fas.harvard.edu/~eoster/hepb.pdf