In China the male-female ratio has been rising at least since the 1980s, and the unmarried males, or “bare branches”, alone are not the whole problem:
In any country rootless young males spell trouble; in Asian societies, where marriage and children are the recognised routes into society, single men are almost like outlaws. Crime rates, bride trafficking, sexual violence, even female suicide rates are all rising and will rise further as the lopsided generations reach their maturity (see article).
So how can we resolve it?
In the 1990s South Korea had a sex ratio almost as skewed as China’s. Now, it is heading towards normality. It has achieved this not deliberately, but because the culture changed. Female education, anti-discrimination suits and equal-rights rulings made son preference seem old-fashioned and unnecessary. The forces of modernity first exacerbated prejudice—then overwhelmed it.
The author inevitably mentioned the one-child policy of China and criticized it. In respect to this matter, I choose to withhold my opinion. It may not be a perfect solution, probably not even a good one – but any other alternative may be even worse for China, with a culture so headstrong to believe that “more children, more happiness”, especially in the rural areas. Here for the full article at The Economist.