While three working people now feed one economically inactive person - children and retirees - they will have to feed two in 30 years' time, according to Census and Statistics Department figures released on Tuesday.

Convoy Financial Services associate director Eva Leung Tsz-ki said employees should have greater say in the percentage of their MPF contributions and choice of service providers.

"There is much more room for the MPF system to make improvements, especially to increase flexibility for employees to make their own investment choices on their MPF accounts," she said, adding that those aged 40 or older should think of higher-value-added investment plans.

University of Hong Kong associate professor Law Chi-kwong, a population expert, said the elderly's quality of post- retirement life will be maintained only by optimizing the current MPF scheme.

More study should be done before establishing the controversial universal retirement protection scheme, he added.

"We have to carefully calculate whether society could afford such an expanding aging population in future decades, otherwise, it will only burden the younger generation," Law said.

Many worry their MPF savings will not be sufficient for their retirement. Ho Chor, 60, started his MPF savings in the past decade and worries he will have to apply for Comprehensive Social Security Assistance after retiring.

"I feel so upset to see homeless elderly who cannot financially support themselves and have to sleep on streets," he said. "I always wonder if a longer life would mean poverty to me?"

Teresa Tsien Wong Bik-kwan, co- director of the Institute of Active Ageing of Hong Kong Polytechnic University, said the elderly should be encouraged to to use their skills in the community.

For example, some seniors worked as part-time tourist ambassadors in Harbour City or promotional ambassadors for the Senior Citizen Home Safety Association or Housing Society Elderly Resources Centre.