You may know that birth sex ratio (the number of newborn males compared to the number of newborn females) is about 103-106 : 100. But combine ignorance (read it cultural preferences for boys), modern reproductive technology and one child policy and here is the result: by 2020 there will be over 37 million extra Chinese men.
The huge number of young Chinese men far outnumbering young women pressed the Chinese government to make tough plans against the sex-selective abortions. There are already 18 million more young Chinese men than women. A recent survey carried on by the China Youth Daily showed that 85 % of respondents were worried about the effects of the gender gap.
In the past, undesired girls were commonly abandoned; while modern technique allows their abortion. As China grows richer, more Chinese couples afford paying an ultrasound pregnancy check for practicing the gendercide.
And annually, 2 million more men are born. Statistics say there are 70 million more boys than girls in China. Official data show a sex ratio at birth of 130 - 135 boys for every 100 girls (!) in the south Chinese provinces of Canton and Hainan (these are absolute world records).
Near border with North Korea, in northeastern China, many villagers buy Korean wives.
According to the Chinese tradition only a son can do the funerary rites for his parents and ancestors.
There are two laws banning doctors to reveal to the parents the sex of the fetus, but the practice is common. One method to avoid the law is for doctors silently to show a thumb-up (when the fetus is a boy) or a thumb-down (in case of a girl, just like in the case of an execution order).
40 million young single men, concentrated in economically poor rural areas (thus sexually and economically frustrated young men) can be a source of social turmoil. Married guys are not so easily eager to go to war or start revolts.
"Some are worried that military adventurism and internal violence could be outcomes for societies with disproportionate numbers of unmarried young men. Some pervert implications of gendercide could be that the increasing global scarcity of women will turn them more "valuable" as a group, like elevating the social status of the victims. But in practice, in societies that practice gendercide, young women are treated even less humanely as they become scarcer: their current lack has in fact triggered an increased women trafficking as sex slaves, and it did not increase their social prestige." said the U.S. Census Bureau's Judith Banister.