With nations around the world failing to reproduce themselves, policy wonks now realise that too few children could be far worse than too many. The challenge now is to boost the number of births. Conventional strategies include baby bonuses, family benefits, extended maternity and paternity leave and more flexible working schedules for mothers.

Some countries have come up with creative solutions. On the sensible side there is Portugal, with a birth rate of 1.5 children per woman. Faced with the bankruptcy of its pension scheme within 10 years, it has debated making people who have fewer children pay more into their retirement fund. On the loopy side there is Japan, where local governments are subsidising speed dating to help time-poor office workers find spouses.

Butte latest fad is promoting in vitro fertilisation (IVF). Last month a conference on assisted reproductive technology in Lyon heard that the low fertility of young Danish women has been almost entirely offset by generous government subsidies for IVF. With a birth rate 0f 1.9, almost replacement level, Denmark is one of the few countries in Europe which has bucked the trend towards falling birth rates. Nearly 1 Danish baby in 20 is a test-tube baby, IVF is socially acceptable, the government pays for up to six cycles of treatment and waiting times are short.

With news like this, it's hardly surprising that other governments are turning to IVF, since nothing else seem to work. These are desperate times for small countries with extinction on the horizon. Demographers say that no country’s birth rate has ever recovered after dropping below 1.5, so governments need to do everything they can to avoid falling into a headlong decline.

Korea has one of the lowest birth rates in the world – 1.16. President Roh Moo-hyun recently vowed spend his last years in office tackling the problems of a rapidly ageing society. About 16,000 childless Korean couples will be able to obtain a government subsidy for half the cost of their IVF treatment. Estonia is also subsidising IVF and hopes to increase the number of IVF babies to about 1 in 30.

But with so much at stake – the very survival of small countries with distinctive cultures like Korea and Estonia – does this make sense? Or is IVF just a band-aid?

Despite lavish IVF subsidies, there is precious little research to support the contention that it will boost birth rates. One study which has been cited by journals like New Scientist and The Economist was published last year by the Rand Europe think-tank. It argued that if Britain supported IVF at Danish levels, there would be about 10,000more children each year.

The cost of six free cycles of IVF would be an extra US$500 to $860million a year. While this is not cheap, it is less costly than bribing women to have children by handing them government benefits. “If the countries of Europe do wish to keep their populations up, making IVF more widely available might be a good way of doing so,” The Economist chirpily concluded.

However, The Economist did not seem to have read the Rand report very closely. The authors were careful to note that this optimistic scenario assumes that women will not delay childbearing because of the greater availability of IVF. Because fertility declines steeply after 35, women who decide to postpone having a family until they have established themselves in a career may not be able to have a child, even with IVF. In fact, a recent poll by the Guardian newspaper suggests that about 35 per cent of British women might postpone childbearing because of the availability of IVF.

If this is true, says the report, “then it may actually have a negative effect on the [total fertility rate] and consequently lead to further ageing of the population”. This seems to be the case. When IVF is heavily subsidised, the Rand analysis shows that it boosts the birth rate slightly. When it is not, the availability of IVF actually depresses the birth rate. What happens is this. Many women in their fertile years balance the cost of having a child against the extra income they could earn in employment and defer having children. In the back of their minds they think that they will have IVF as a safety net.

The years tick on, and in their mid-30s, the alarm on their biological clock goes off. They begin trying for a child. Many of these older women will fail. If IVF is heavily subsidised, then many of these failures will clutch for their safety net. Some lucky ones will have children, giving a small fillip to the birth rate.

But if IVF is not subsidised, women discover to their dismay that it is horrendously expensive. They cannot afford it and they have to give up their dream of having children. So the availability of IVF acts as a will 'o the wisp, a flickering beacon of hope, allowing women to invest so heavily in their careers that they are unprepared for the inexorable fading of their precious fertility.

The report casts even more cold water on IVF as a way of rejuvenating dying countries. The health of babies born to older women and from IVF is poorer than children born to younger mothers and through natural conception. Older women have more Down syndrome children. There are far more multiple births for women with IVF treatment, which is associated with poor child health. IVF is also associated with low birth weight and prematurity and a higher risk of birth defects. “These health effects and other unintended consequences should be taken into account when assessing the impact of [assisted reproductive technology] as part of a population policy mix,” it says.

Talk of IVF as a solution for declining birth rates is a sign that clueless governments are clutching at straws. Low fertility is a complex issue with social, economic, medical and environmental factors. But addressing these alone is just tinkering around the edges.

Ultimately low birth rates are a cultural and ethical problem, a sign of a world-wide spiritual crisis. Having children is simply not viewed as a fulfilling life project any more by many couples. Only when young men and women turn away from consumerism and individualism will birth rates begin to climb beyond replacement levels.