THE proverbial stork now comes much later and on fewer occasions, too.

Not surprisingly, the size of the average Singapore family has shrunk sharply.

Among women aged 40 years or older who have ever married (that is, among those who are quite likely to have already completed their child-bearing) the average number of children has fallen continuously since the 1990s - this, despite a slew of generous procreation incentives introduced in recent years.

Singapore women in their 40s, for instance, gave birth, on average, to a total of 2.75 children in 1990.

But by last year, most of them would have had babies, at most, only twice in their lifetime (an average of 2.07 children).

(My own better half is in this category and we have two grown-up daughters.)

Dwindling dramatically

Even among the older generation (women 50 years or older), the average number of children has also dwindled dramatically - from 4.69 in 1990 to only 3.03 by last year.

Amazingly, despite a faster-growing population in Singapore since the start of the new millennium (arising chiefly from the influx of new immigrants), the number of locally-born children has stayed consistently below 40,000 a year since 2003 - when a serious Sars epidemic placed a big dampener on the local economy.

Earth Dragon high

This low birth rate situation in 21st century Singapore pales in comparison to the all-time high of 52,957 newborns in 1988, during the auspicious year of the so-called Earth Dragon, when the Singapore economy was also on the up and up.

To be sure, with three-quarters of all Singaporeans still of Chinese descent, zodiac signs will likely remain an important consideration as to when many newlyweds should start their families (and when we can expect a bumper harvest of new babies).

More recently, however, the cyclical ups and downs of the Singapore economy have become equally important for the many married Singaporeans who remain childless by choice, especially during their first five years of marriage.

But what do oxen, tigers and dragons (plus nine other zodiac sign animals) have to do with when our newlyweds will take their first plunge into parenthood?

And how has this time-tested formula for family planning been rudely interrupted by the periodic economic dislocations that we've experienced since the mid-1980s?

Back in 1985 (a year of the Ox, a beast of burden), when Singapore experienced the onset of its first full-blown post-Independence recession in 1985, there was widespread workforce retrenchment.

Lag time

But given the (ahem) unavoidable lag of about nine months between conception and birth, the sharp drop in new babies showed up only in the following year (which back then also coincided with an avoid-it-if-you-can year of the Tiger).

A similar delay-parenthood-if-we-can pattern showed up in mid-1997 (another year of the Ox) when the onset of the Asian currency crisis led to another sharp economic downturn (this time, on a much broader, region-wide, basis).

Not surprisingly, Singapore went through a prolonged two-year baby bust - starting in 1998 (another year of the Tiger) and spilling over into 1999 - before the return of confidence and a new Dragon year in 2000 (at the height of the dotcom boom) helped our newlyweds overcome their fears about first-time parenthood.

Short-lived boom

But this baby boom soon proved short-lived when the ensuing dotcom bust of 2001 and then (horrors) the subsequent Sars slowdown of 2003 all but ensured that the number of new babies thereafter would stay permanently below 40,000 a year.

And just when you think the worst is over, here we are, once again, about to set off for yet another economic (and family-planning) roller-coaster ride.

The Ox returns

With the onset of the global credit crunch in late 2008 - and with further economic uncertainties in store for us next year (another year of the Ox!) - expect the next baby bust to last at least two years (inclusive of another Tiger year!).

But if life is an ever-repeating zodiac cycle (like what most Chinese families think it should be), expect a rebound in new babies by 2012 (another Dragon year).

That's when, thankfully, you can also expect a full-fledged global economic recovery.

Zhen Ming, a Harvard-trained economist based in Singapore, is a freelance contributor.

This article was first published in The New Paper on Dec 14, 2008.