Beijing, China ? China’s population of 1.3 billion people would be 400 million higher if not for the government’s policy of limiting most families to one child, state media reported Thursday.

The “one-child” policy has slowed population growth and contributed positively to the country’s socio-economic development, the Xinhua News Agency said, citing a family planning official.

But Zhang Weiqing, the minister in charge of the State Population and Family Planning Commission, said China needed to address the problems of an imbalanced sex ratio and an aging population, the agency reported.

The communist government has limited most urban couples to one child and rural couples to two since the 1970s to try to restrain the growth of China’s population and conserve scarce resources.

Critics say the policy has led to forced abortions, sterilizations and a dangerously imbalanced sex ratio due to a traditional preference for male heirs, which has prompted families to abort female fetuses in hopes of getting boys.