The number of older workers taking home less than $1,000 a month has doubled to nearly 35,000 over the past decade, according to figures from the Ministry of Manpower.
That number has outpaced the natural ageing of the population, which had slightly more than 400,000 residents aged 65 and above last year, up 60 per cent from around 250,000 a decade earlier.
More elderly people may be working because there are fewer children to provide support, or the children themselves may be struggling with rising costs, said Assistant Professor Ng Kok Hoe of the Lee Kuan Yew School of Public Policy.
"Studies have shown that fewer parents are living with children and fewer are receiving cash transfers from them," said the social policy expert, who has published a paper on how poor Singaporeans may not be able to depend on their children as the primary source of retirement income for much longer.
"So some older folk may have no choice but to turn to work to make ends meet."
Although there are twice as many low-income elderly workers now, there was some good news in the statistics - only one in three earned under $1,000 last year, compared with one in two just five years earlier.
This could be the result of several recent government incentives to get more of the elderly into the workforce, said labour economist Randolph Tan of SIM University.
Companies get a Special Employment Credit to hire older workers. The tightened foreign worker tap has led to more jobs in the cleaning and service industries.
The unions have also pushed for the implementation of National Wages Council recommendations for a minimum $60 hike in the pay of older workers who earned below $1,000.
"Given the tight labour market, companies are being motivated to pay higher wages than before to woo Singaporean workers back to the workforce," said Associate Professor Tan.
In 2003, only about 12 per cent of those aged 65 and above worked; last year, that proportion doubled to 24 per cent.
Workers appear to be willing too. "They can now supplement take-home pay with Workfare, which has become an important pillar of social support," said Prof Tan. "So there are more incentives to work than before."
Workfare payments are made quarterly and not factored into calculations of gross monthly wages. A worker aged 65 who earns $1,000 a month, for instance, can get $350 in cash and $525 in Central Provident Fund grants every quarter from Workfare.
Prime Minister Lee Hsien Loong announced in his National Day Rally speech last weekend that the Government planned to institute an annual "Silver Support" bonus to help low-income Singaporeans aged 65 and above.
Member of Parliament Lily Neo, whose Tanjong Pagar constituency is home to many who are old and poor, said she hoped the bonus would be paid not just to retirees but also to working low-income Singaporeans.
Among them is mother of five Lee Soon Chiew, 67, who told The Sunday Times she works as a cleaner because she does not want to be a burden on her children. "They all have their families and don't earn much. I have no choice but to work," she said.
Hawker centre assistant Yip Chin Foon, 77, a sprightly single who works five hours a day, five days a week, said: "I do not want to depend on the Government. I just want to work as long as I can."