Shanghai, like many major cities around the world, is entering a gray area.
About a third population with local residency would be aged 60 or above in 2020, while families in the city were getting smaller and with fewer children, the Shanghai Population and Family Planning Commission said Friday.
Shanghai is China's most populous city, with 18.58 million residents in 2007. There were 6.6 million migrants in the city, including the 4.99 million staying in the city for more than six months.
The city saw an annual increase of 300,000 residents between 1990 and 2007, mainly due to the migrant influx.
About 20.8 percent of local residents were 60 or older in 2007. In 2020, 34 percent of local residency will enter that bracket.
At present, 3.05 million families have only one child, accounting for 61.06 percent of the total number of families. The percentage is 39.09 higher than the national average.
"Shanghai has an unbalanced population structure," said Xie Lingli, commission director. "However, the family-planning policy really cut an estimated 7 million people, effectively enhancing local economic development and easing pressure on the environment."
According to Xie, the city had an improper population distribution.
"Over half of people, which is about 9.76 million, live in downtown areas covering only a tenth of the local area," she said. "Overcrowding results in busy traffic, rising living costs and poor environmental quality."
Officials said the city would work out plans to control population in line with the local economy and resources, study urban-development strategy and infrastructure under the increasing population, ensure better population distribution in urban and rural areas, perfect population management and the public service system and establish an alarm system on urban-population safety.