When it comes to piloting new policies, Shanghai has never been shy in taking the driving seat - including with pensions.

In October 2010, this eastern metropolis became the first to introduce a flexible retirement plan, allowing some people to delay the day they need to punch out for the final time.

Today, roughly 80 percent of high-skilled workers who have reached pensionable age are still working, according to the city's human resources and social security bureau.

Under the pilot regulations, people in professional and technical positions can decide to push back their retirement, while lower-skilled employees can also apply if they reach an agreement with their company, regardless of ownership or size.

For men, that means they can extend their working life from 60 to 65, while women can continue working until their 60th birthday, instead of calling it quits at 55 (civil servants) or 50 (ordinary workers).

Liu Fenghua, a 56-year-old forensic pathologist for Shanghai Public Security Bureau, was among those who opted to keep on working last year. She said applications are open only to female workers at a level of deputy department head or higher, which means just a small proportion of potential retirees qualify under the pilot.

"To do my job in the laboratory demands experience and skill," she said. "It's also better for newcomers to be observed and coached by veterans."

Liu explained that one of her motivations for staying on was the large difference in income between someone who is employed and someone who is retired.

"I get considerable allowances for meals and commuting, and other subsidies, but that would all stop if I retired," she said.

Li Min, also 56, works at a quality inspection agency. She also chose to continue working last year and said she believes many of her peers will do likewise.

"I didn't calculate too much about whether it's a gain or loss. I like the working atmosphere, and I'm afraid of the sense of loss (if I stop)," she said.

According to Shanghai's population and family planning commission, more than one in five residents are aged 60 or older, making the city one of the "oldest" in the country. Meanwhile, the gap between the incomings and outgoings of the city pension fund is 10 billion yuan ($1.57 billion) a year.

"The pilot policy will help ease the pressure and respond to people's varied needs," Bao Danru, deputy director of the Shanghai Human Resources and Social Security Bureau, told Xinhua News Agency in October 2010. "People can make their own minds up."

The policy is only promoted among highly skilled workers, rather than all workers, which will avoid limiting the employment opportunities for younger generations too much, he added.

However, not everyone covets the chance to work longer.

"Can we compete with the young in terms of energy, enthusiasm and thinking?" said Wang Jiaming, a senior manager at a State-owned factory in Shanghai. "It isn't worth it to keep on fighting in old age."

Meanwhile, some people said they would rather look for a new job after retirement to ensure double pay a salary from a new boss and a pension. Businesses are also keen on hiring them, because they are not required to pay their social insurance.

"I'm considering a job offer from a foreign company, because I feel it will be meaningless to keep on repeating the work I've done for 20 years," said 53-year-old Fan Yifang, who works at a banking institution.