In China there are 24 million young men unable to find wives, and in the cities of Shenzhen and Dongguan unmarried men outnumber women by as much as five to one.
So why are there so few girls?
China has a one child policy, so in the poorest parts of rural China, where hard manual labour is necessary for survival and males inherit more land, the preference is for boys.
It means that many girls are given away, abandoned, aborted, and in the past even killed at birth.
Chinese author and broadcaster Xinran talked to Lucy Ash about the untold and disturbing stories of countless mothers who have lost their daughters.