In past years, Shanghai has slowly made itself more open to outsiders, allowing certain migrants to apply for Shanghai hukou. The increasing number of incomers has helped restore balance to the city's population, which had been becoming steadily older on average.

In future years, the city will continue to attract young migrant workers, especially those between the ages of 25 and 35. Its goal is to replenish a labor pool that has begun drying up, in part because more and more workers are reaching retirement age and in part because the birth rate in the city is low, said Xie Lingli, director of the Shanghai municipal population and family planning commission.

The commission predicts that, by 2015, the number of workers in Shanghai between the ages of 16 and 59 will drop from 9 million to 8.3 million.

"In this regard, the government should work harder for the migrant population and allow migrants to receive the same social welfare as registered residents and help them better integrate into the city," Ren Yuan said.

In addition, about 5.05 million Shanghai residents hold university degrees. According to the 2000 census, 109 out of every 1,000 Shanghai residents had held university degrees; that ratio has now risen to 220 out of every 1,000, according to the Shanghai municipal statistics bureau.

"The figure reflects the great achievement shown in the city's education work and it attempts to attract talented people from other areas," the bureau said.