This is an enormous problem that has been largely ignored because of the complexities of demographic forecasting. However, it is very real. Henry Luke May 5, 2015
Bare branches, redundant males
Distorted sex ratios at birth a generation ago are changing marriage and damaging societies in Asia’s twin giants
The Economist Apr 18th 2015 | From the print edition
“Missing girls, missing brides
The roots of the current squeeze go back a generation. Sex-selective abortions became common in China in the 1990s as a result of the country’s strict (now somewhat laxer) one-child-per-couple policy and a traditional preference for sons. A few years later they became increasingly common in India, also because of a preference for sons and helped by the growing availability of prenatal tests to determine sex. In 2010-15, according to the UN Population Division, China’s sex ratio at birth was 116 boys to 100 girls; in India the figure was 111. Though these ratios have fallen a little since their peaks, they are still far above the natural rate, which is 105 to 100. There are other factors that will increase the problem over the next 20 years.
The combination of other factors (described in the article) in India and China will make their marriage squeeze especially acute and persistent—much more severe than it would have been in the case of distorted sex ratios alone. Mr Guilmoto calculates that, in China, for every 100 single women expected to marry in 2050-54 there could be as many as 186 single men; in India in 2060-64 the peak could be higher: 191 men for each 100 women. This assumes the sex ratio at birth does not change. But even if the ratio were to return to normal in 2020 (which is unlikely), the marriage squeeze would still be severe, peaking at 160 in China in 2030, and at 164 in India 20 years later.
A marriage squeeze of this intensity would be unknown in China and India and extraordinarily rare anywhere in history.
A study by Lena Edlund of Columbia University and others found that in 1988-2004, a one-point rise in the sex ratio in China raised rates of violent crime and theft by six to seven points. The abduction of women for sale as brides is becoming more common. The imbalance is fuelling demand for prostitution.”