To my biased cultural sensitivities, this is some fucked-up bullshit.

But beyond that: it feels like this gender unbalance simply can't be stable in the long term. At some point, women become a scarce resource and thus more valuable.

Maybe there are some hints of that happening already. For example, this episode of Vice shows that dating in China has started to become more and more difficult for men. http://hbo.vice.com/episode-four

I can't imagine what these countries will look like if this gender disparity persists for 100 years or more.