In 2020, there will be 30 million more men than women in China.

One of the causes of this gender imbalance is the traditional preference of the Chinese for men. Sons are favored because China's vast lands need field laborers -> men! They are also the ones who can pass on the family name and are expected to take care of the parents.

Girls, on the other hand, are expensive since parents need to cough up an amount for their dowries when they get married.

Another reason cited for this gender imbalance is the one-child policy, which was implemented in the 70s to control the population. And since families can only have one child, they chose to have girls aborted to make sure that they only have a son.

The predicted gender imbalance is a big cause for worry since young Chinese men will not be able to find spouses which could cause several social problems like increase in sex outside of marriage, swindling and selling of women.

source: CNN