The point system for a migrant resident, which took effect in July 2013, was one way to control the population rise, experts said.

The system translates migrants' personal circumstances and contributions into points on their residence permits corresponding to the public services that they are eligible for. The points will be accumulated and a total of 120 can win the migrant resident major social benefits, such as social insurance or allowing their children to take the national college entrance exam in Shanghai.

High-end talents will be prioritized in applying for permanent residence as Shanghai's quest to become a global science and technology center by attracting top talent from home and abroad is quickly gathering pace.

Ren Yuan, a professor from the School of Social Development and Public Policy at Fudan University, said the economic boom in neighboring Zhejiang and Jiangsu provinces will reduce the pressure on the city.

"When the root cause of the development gap between regions is alleviated, the one-way flow of population migration will slow down," he said.

Zhou forecast that it's very possible Shanghai will have 30 million people by 2030, and he believed the rise will be essential to improve the age structure of the population in the long term.

"Moreover, decisions in every aspect of social and economic development should be based on consideration of population growth. Otherwise the difficulty of admission to kindergartens and primary schools will go on and the fact that a doctor in a hospital in Shanghai will see hundreds of patients on a daily basis won't change," Zhou said.