Fearing the costs of an ageing population, policymakers here are frustrated by our low fertility rate compared to that of other nations.

It would be more relevant, though, to compare Singapore’s fertility rate against that of major cities, such as London, New York, Tokyo or Shanghai.

On Feb 26, 2008, the United Nations released a report forecasting that half the world’s population would live in cities by that year’s end, and Singapore bears witness to the rise of cities.

The tremendous urban population growth is driven not by urban birth rates, but by migration from the more fertile rural population. For large countries, it means the cities are taking in their country cousins. For city states, it means absorbing immigrants.

This distinction is significant not only for Singapore’s cultural identity but also its economy. Each adult immigrant here arrives fully paid. Another nation bore the cost of giving birth to, feeding, clothing, accommodating and educating that person.

Regardless of whether the education is in state schools or private, the cost of raising an adult to university level in Singapore is over half a million dollars, with the bulk going to education.

Thus, Singapore saves that much on every well-qualified foreign graduate that comes to work here, and perhaps two-thirds of that for an immigrant qualified to the A-Levels.

Immigrants hit the ground running and contribute to Singapore’s gross domestic product during their careers here. Better still for our economy, many of these foreigners will not stay here for good, but will leave before they retire and become a burden on our state.

This is unlike the extreme problem Japan faces with its greying population and few immigrants to refresh it.

So, we can survive the effects of an ageing Singaporean populace by cycling foreign talent through the workforce.

With careful planning, we can adjust the volume and composition of our imported workforce according to our local population’s age profile, without necessarily increasing the total resident population.