China has in recent history taken drastic measures to reduce its population, but officials in Beijing this week say they have a new problem: an underpopulation of women.
For years, experts have warned that China's birth control policies limiting urban couples to one child would lead to a surplus of men and not enough women.
Traditionally, Chinese parents have favored male offspring who some believe can take better care of them in their old age. This view and the lack of a viable social security system pressured many couples to use medical procedures such as ultrasound and amniocentesis to determine the sex of their unborn child and then abort the fetus if it is a girl.
This week, Chinese officials repeated their hard-line ban on selective sex abortions and the trafficking of children. Zhao Beige, vice minister of China's National Population and Family Planning Commission, says tougher enforcement and longer-term policies are necessary to help change people's preferences for baby boys.
"I think it is important that we establish a social security system in the rural areas. We already have regulations to ban the practice of sex selection abortions using medical equipment."
Doctors can be fined or lose their license if they agree to use medical procedures to determine the sex of an unborn child. However, officials say physicians often flout the laws, sometimes in return for bribes.
Chinese officials say that currently, there are 117 boys born for every 100 girls, compared to the international norm of 105 boys.
International experts estimate China's imbalance is about 121 boys for every 100 girls, much higher than the official figure. Some estimate it is as high as 135 in some rural provinces. U.N. officials say that without changes in the sex ratio, up to 60 million women may be missing from China's population in the next decade.
Chinese leaders recognize this as a serious issue. President Hu Jintao, at this year's annual session of the National People's Congress, China's parliament, said the government must try to raise the ratio to normal levels in six years.
Valerie Hudson is a politics professor at Brigham Young University in the United States who has recently co-written a book on sex ratio imbalances in Asia. She has drawn a link between disproportionately high male populations and violence. She sees early signs of problems in China.
"There is some evidence that crime rates are increasing dramatically in China and that most of the violent crime being perpetrated is by unmarried, single males in this young adult period," she explained.
Professor Hudson says China's leaders are heading in the right direction with educational programs on gender equality. But she says no rapid solutions are likely, as the generation born in the 1980s when sex selection procedures started, comes of age.
"The problem is that initiatives that begin now of course don't address the last 20 years in which the imbalance occurred. So China is realistically looking at another 20 years of problems," professor Hudson said.
Researchers say sex ratio imbalances are not unique to China but are endemic to much of Asia. They say India, whose population is expected to surpass China's in 25 years, has a similar gender ratio problem, as do South Korea, Pakistan, and Bangladesh.
With nearly half the world's population concentrated on the Asian continent, experts warn that the consequences of the so-called "missing" women could be wide reaching.
