Foreignpolicy.com has an exceedingly interesting paper on the gender imbalance in Asia, aptly titled The Geopolitics of Sexual Frustration. The larger number of men than women on that continent is having unforeseen consequences, of which extreme nationalism may be one. One scenario that they posit:
A Beijing power struggle between cautious old technocrats and aggressive young nationalists may be decided by mobs of rootless young men, demanding uniforms, rifles, and a chance to liberate Taiwan. More likely, the organized crime networks that traffic in women will shift their deliveries toward Asia and build a brothel culture large enough to satisfy millions of sexually frustrated young men.
One aspect of the article that goes against accepted wisdom: it is not the poor that choose boys over girls.
It would be reassuring to assume that China’s economic growth will itself solve the problem, as prosperity removes the traditional economic incentives for poor peasants to have sons who can work the land rather than daughters who might require costly dowries. But the numbers don’t support that theory. Indeed, the steepest imbalance between male and female infants is found in more prosperous regions, such as Hainan Island. And census data from India suggest that slum-dwellers and the very poor tend to raise a higher proportion of female children than more prosperous families.