The world population hits 7 billion people on Oct. 31st. As the most populous nation in the world, China implemented rigorous family planning policy 30 years ago. Many policy makers in China believe it has avoided 400 million extra births.

Most Chinese experts agree the population of China would have hit 1.7 billion had it not been for the family planning policy.

In the late 1970s, China introduced the family planning policy. Previously, people were encouraged to have large families. But out of concern for natural and energy resources - and lately out of environmental concerns - families were encouraged to have one child.

The effects of the policy are debated, but for a leading Chinese demographer, the policy had postponed the arrival of the world population of 7 billion by at least five years.

Lu Jiehua, professor from Peking University, said, "The reform and opening-up policy has not just helped China’s economy. It has also promoted population control. Over the past 30 years, we have

contributed to a favourable environment for the country’s economic development and social stability."

But China still faces serious challenges. There is a serious gender imbalance due to the traditional preference for boys. Also, due in part to the family planning policy, China suffers from an ageing population.

Dean Zhai Zhenwu from Population Institute of Renmin University, said, "We must follow the family planning policy for it has decreased the world population and promoted economic development. But with the development of population, China is facing disparities between an ageing population and population distribution."

Re-evaluating and improving the existing family planning policy will be one of the major tasks in the future to promote a more balanced population development.