SINGAPORE: South Korea, Hong Kong, Taiwan and Singapore have over 40 years averaged roughly the highest consistent economic growth rates in the world. All but Korea have steadily accumulated massive surplus savings and foreign reserves.

But change the national accounting principles behind these rosy numbers and a different picture emerges, one that the societies concerned have barely begun to grapple with. In one vital respect these countries (soon to be joined by China) collectively may have the worst record of investment in the future since homo sapiens evolved: Investment in the next generation.

They have the lowest fertility rates in the world. Hong Kong is at the bottom (excluding births to non-residents), with around 1.0 births per woman of child-bearing age (the replacement rate is 2.1). Taiwan, Singapore and Macau come in at 1.1, while South Korea, at 1.2. is on par with Europe's lowest, Belarus. None of these economies has had replacement-rate fertility levels since the late 1980s.

Now, imagine if national income data included all spending by parents and government on food and clothing, education and health care as investment, and gave an economic value to time spent in child-rearing rather than paid employment. The GDP of Asian countries like Malaysia and Indonesia, or much of the middle income developing world of Latin America and the Middle East, would be a lot higher, while South Korea, Hong Kong, Taiwan and Singapore would show a steadily declining proportion of investment in the future. Economists forget that people as well as buildings depreciate at a roughly predictable rate. Child-rearing is at least as essential as building roads.

Imagine if these four economies had invested less in infrastructure and reserves and more in people. They would now most likely have much lower foreign-exchange reserves, but they would not be facing a situation in which their work forces - unless replaced by immigrants - will decline dramatically within 20 years as the population over 65 continues to grow. The payback for years of what may well have been the misallocation of resources is not far in the future.

Relying on immigration may be a partial answer, particularly for Singapore and Hong Kong. But this prospect does not explain why neo-Confucian East Asia is consistently showing the lowest global fertility rates. (Singapore's non-Chinese have higher rates than the Chinese majority. In China, too, cities such as Shanghai show similar patterns to Hong Kong, which have little to do with the One Child policy.)

Governments in Singapore and South Korea have made efforts to increase fiscal incentives for child-rearing, but they are still only a fraction of the income a family loses when a parent stays at home, and the results have been modest. The problem may run deeper than simply the cost of parenthood, even in places like Singapore, where the middle classes have ready access to cheap foreign domestic help and where social engineering policies once tried to encourage the higher-educated to have more children while discouraging births among lower income (and by implication non-Chinese) families.

These countries, despite their shared Confucian traditions, have varied records in equality and workforce rights - from reasonable in Singapore and Hong Kong to poor in Korea and mainland China, where gender imbalances are endemic. Society puts much emphasis on the family rather than the state or individual. However, in practice this has led not to child-rearing but to high household savings rates, whether to buy an apartment or prepare for old age.

All four economies have costly housing but high home-ownership rates. So even at the family level, the value of the future workforce is not given its due.

The scramble for wealth and a shift to unitary living has undermined the belief that children are a protection against the uncertainties of old age. Yet the state, on the assumption that old values should prevail, has yet to fill the gap. State budgets show huge surpluses, but by taking scant heed of the needs of parenthood or the elderly. (Hong Kong is a particular disgrace when it comes to treating the latter).

Government and society alike seem reluctant to look at experience in Western countries, which are normally condemned for costly welfarism. Yet fertility rates tend to be highest in the Scandinavian countries, the Netherlands, France and New Zealand, where both women's rights, workforce equality, maternity leave, and state support for nurseries and other support services are mostly high - and where births outside marriage are also sometimes high - in the 1.7 to 2.1 range. (The relatively high U.S. fertility rate is mainly attributable to immigrant groups).

Neo-Confucian Asia has provided education and jobs to women, but has yet to make the adjustments to achieve the fertility levels that countries need and that most women say they want.

Almost all developed and many developing countries now face demographic challenges from a reverse in the high fertility rates of the past. There are no easy solutions. But by changing national accounting principles to make child-rearing a priority, attitudes toward it might change too.