Associate editor Vikram Khanna has given us a comprehensive analysis of the problems facing Singapore currently, namely ageing, immigration and productivity (Reframing the debate on ageing and immigration; Jan 31).

Many countries, including Singapore, are experiencing a combination of declining birth rate and increasing longevity. Greying populations pose serious issues for society, especially policymakers.

One way to overcome the economic constraints would be to boost productivity, so that more goods and services are produced from the same amount of input, hence giving society more output to divvy up.

However, while production may increase as the population ages, there comes a point where the effects of ageing begin to affect the majority of workers. Production would experience a decline.

New technologies, research and development, exports, imports and foreign direct investment have to be key drivers of productivity.

Improved education among the population aged above 60 and delays in retirement among better educated workers, will help to boost the earnings of older workers.

Meanwhile, migrants can take jobs where natives are in short supply, such as bus driving, construction jobs, healthcare services and domestic help.

Migrants help to expand an economy's productive capacity, stimulate investment and, in the long run, boost productivity.

This was seen in the United States in the 1930s and 1940s, when there was an influx of German Jewish emigres, as well as in Germany in the 1960s, when Turkish workers helped it catch up with the US in productivity terms.

Singapore's economy should do well with an ageing population and controlled immigration policies.

Heng Cho Choon