As China's President Hu Jintao makes his first official visit to the United States this week, his nation faces a demographic time bomb that could affect its stability.
With more than a billion people, China has too many men. According to the latest census, an average of 120 boys are born for every 100 girls, the greatest imbalance in the world.
As correspondent Lesley Stahl reports, the root of the problem is a traditional preference for sons. In China, as in other Asian countries, it is sons, not daughters, who usually take care of their parents in old age.
To deal with its population explosion, China imposed its strict and harshly enforced one-child policy in the 1980s, and that's when things started going out of whack, as couples, faced with having only one child, went to great lengths to ensure it was a boy. And 60 Minutes found they still do.
60 Minutes visited Linchuan, a small village in Jiangxi province in southern China, where the absence of girls is most acute.
When Stahl went to the No. 10 high school here, with its 7,000 students, the problem was clearly visible: there were far more boys than girls. For every 100 girls, there are 150 boys.
One class of high school juniors insisted that the lopsidedness didn't bother them, until Stahl pressed the case.
When asked whether they wished that more girls were in the school, both boys and girls answered with a resounding "yes."
The one-child policy is 25 years old, so the first generation is just now reaching marriage age, and for China that's a big problem because it is estimated that as many as 40 million of its young men could spend their lives as bachelors.
Some of these men have joined the country's floating population — 140 million migrants who move to the cities like Beijing in search of work. The 60 Minutes team came upon a group of men on a street corner, where they gather every day, illegally, hoping for day jobs.
Before the police came to shoo them and the TV crew away, Stahl asked them some questions with the help of an interpreter.
Asked if it is hard to meet women and get married, a man told Stahl through the interpreter: "He was saying you have to have a little wealth before you can get married. ... If you're poor, nobody will go with you."
The gender imbalance grew out of communist China's draconian social engineering policies, where a woman, after having one child, was forced to make a choice: sterilization or insertion of an IUD (intrauterine device).
To make sure the women kept their birth control devices in, the government — starting in 1982 — sent portable ultrasound machines all over the country. They are compact and lightweight and even some small villages got as many as two or three. But in a classic case of unintended consequences, pregnant women realized that the machines could also identify whether they were having a boy or a girl. And, as a result, by conservative estimates, more than 8 million girls were aborted in the first 20 years of the one-child policy.
The government has tried to discourage these abortions. Zhao Baige, vice minister of the Family Planning Commission, says it is now illegal to get an ultrasound in order to identify the sex of a baby.
"It is against the law," she explained.
A pregnant woman can still get an ultrasound, but only if it's medically necessary. To make sure the sex of the fetus is not revealed, two doctors are present and the exam is recorded on closed-circuit TV.
If a doctor told an expectant mother the sex of her baby, Zhao says the physician wouldn't be able to continue his or her job and would be fired.
But Chinese couples determined to have a boy can get around the restrictions on ultrasounds by going underground, in back alleys, where illegal storefronts have sprung up to meet the demand. Ultrasound machines are inexpensive in China; they cost about $360 and, as 60 Minutes saw, they are small enough to be hidden in a closet or even in the trunk of a car to do scans on the run. And that's made it difficult to crack down.
We showed the minister some Chinese newspaper photos of a van parked in a Beijing suburb doing ultrasounds in the back.
"We need a more enforcement," Zhao said.
"Well, one of the ways that this imbalance came about is through abortion. Millions and millions and millions of abortions. Why didn't the government clamp down on that?" Stahl asked.
"Let me go to another point," the vice minister replied.
Her "other point" was that China's abortion rate is going down, but she didn't explain why abortions are still free and legal right up to the ninth month, even as the boy-girl imbalance grows.