Another monumental demographic mistake?

The world's most populous nation, which has built its economic strength on seemingly endless supplies of cheap labor, China may soon face manpower shortages. An aging population also poses difficult political issues for the Communist government, which first encouraged a population explosion in the 1950's and then reversed course and introduced the so-called one-child policy a few years after the death of Mao in 1976.

That measure has spared the country an estimated 390 million births but may ultimately prove to be another monumental demographic mistake. With China's breathtaking rise toward affluence, most people live longer and have fewer children, mirroring trends seen around the world.

Those trends and the extraordinarily low birth rate have combined to create a stark imbalance between young and old. That threatens the nation's rickety pension system, which already runs large deficits even with the 4-to-1 ratio of workers to retirees that it was designed for.

Demographers also expect strains on the household registration system, which restricts internal migration. The system prevents young workers from migrating to urban areas to relieve labor shortages, but officials fear that abolishing it could release a flood of humanity that would swamp the cities.

As workers become scarcer and more expensive in the increasingly affluent cities along China's eastern seaboard, the country will face growing economic pressures to move out of assembly work and other labor-intensive manufacturing, which will be taken up by poorer economies in Asia and beyond, and into service and information-based industries...

The sheer magnitude of the aging phenomenon has Chinese officials and academics grasping for answers, but almost everyone agrees that there are no easy fixes. Population experts here speak of "patching one hole and exploding another."

China has a wide range of retirement ages, generally from 50 to 60. Raising the retirement age would relieve pressures on the pension system but make it harder for young people to find jobs. And it would be resented by many elderly people, most of whom have missed out on China's economic boom.

Lifting restrictions on internal migration raises the unwelcome prospect of a mass migration, while abandoning the one-child policy would be politically unpalatable.

The government has already tinkered with the policy. It now allows husbands and wives who were their parents' only children to have a second child, for example, and has eliminated a four-year waiting period between births for those eligible to have a second child.

But Chinese demographic experts say the leadership is unlikely to abolish the one-child rule, because it is reluctant to admit that one of its signature policies was in any way a failure — particularly in view of the disastrous population boom encouraged by Mao in the 1950's.

Moreover, lifting child-bearing restrictions might not help. Poorer people in the interior might have more children, but the rising middle class probably will not, experts say.