DAFENG, China - When asked why she and her husband do not want a second child, Shi Xiaomei smiles at her pudgy 9-year-old son and does a quick tally of the family budget.
Her salary as a cleaning lady and the income from a mah jong parlor in their spare room barely cover their son's school fees and other expenses.
"With just one, we can give him nicer things. But if you tried to split what we have between two or three, they would all end up with nothing," the 34-year-old says at her home in Dafeng, a prosperous but still-rural county 185 miles north of Shanghai.
For years, China curbed its once-explosive population growth with a widely hated one-child limit that at its peak led to forced abortions, sterilizations and even infanticide. Now the long-sacrosanct policy may be on its way out, as some demographers warn that China is facing the opposite problem: not enough babies.
Though a little-known exception allows a second child when both parents are single children themselves, there are few takers.
Officially, the government remains committed to the one-child policy, but it has commissioned studies last year on what would happen should it eliminate the policy or do nothing. A National Population and Family Planning Commission official said privately that the agency is looking at ways to refine the limit without getting rid of it.
A people shortage may seem unlikely in a country of 1.3 billion, the most in the world. The concern, though, is not with the overall number. Rather, as the population shrinks, which is projected to begin in about 15 years, China may find itself with the wrong mix of people: too few young workers to support an aging population.
It is a combination that could slow or even reverse China's surging economic growth.
In a survey of 18,638 women in Dafeng and six other counties in Jiangsu province, 69 percent of those eligible to have a second child said they would stop at one, with economics being the major factor. The Chinese Academy of Social Sciences survey did not calculate a margin of error.
In the 1970s the average Chinese woman had five to six children. Today, China's fertility rate is 1.5 children per woman. Most families have just one, but exceptions allow multiple children for ethnic minorities and a second one for rural families whose first baby is a girl.