Overall population growth has been a visceral issue since the last election, reaching a peak of discontent with the publication of the White Paper on the working assumptions up to 2030. Many were equating the matter solely with living space and job scarcity if the population grew to between six and seven million, bumped up by immigration.
Those who still hold to this position should ponder the latest population statistic showing the country had its slowest rate of growth for a decade last year - at 1.3 per cent to reach 5.47 million. Citizens accounted for six in 10 persons. With a slower intake of foreign professionals and immigrant labour, and with more rapid development in infrastructure to relieve pressure, the old complaints are less insistent but they might never dissipate.
Studying birth rates, life expectancies and net migration gain or loss in relation to a country's economic performance and quality of life, demographers see deficiencies in the profile. The nexus ought to worry the average Singaporean, too. One troubling figure is the old-age support ratio, with its implications of lower tax revenue and higher social spending. It has halved in one generation - from 10.4 working adults for each person aged 65 plus in 1990, to 5.2 last year.
For an economy without a fallback on the bounty of nature, this is unsustainable. Erosion of economic vitality has long haunted the political leadership; the challenge has been how to make sense of it to the people and convince them about what needs to be done. The furore ignited by the White Paper showed how hard it is to debate the issue dispassionately. Sooner or later, it will have to be confronted anew to seek a balance between quality economic growth and optimal population size.
Japan and some East European countries provide object lessons in uncompensated ageing and consequent loss of competitiveness. Japan would lose a third of its population by mid-century because the Japanese people will not have immigrants in their midst. A lesson for Singapore here? China has begun to ease off on its one-child stringency, alarmed that its rapid rate of ageing relative to births could see the population reduced by about half by the end of the century.
Singapore's citizen population will start to decline in about 10 years without immigration gains. While encouraging more births has been a struggle, another concern is outflow. There are 212,000 citizens abroad (10 years ago, it was 158,000), although the statistics do not indicate how many among them have their usual residence in Singapore. The bottom line is inescapable: Singapore cannot depend on indigenous growth alone to maintain its vitality.