The world's developed nations, and many of its less developed ones in Eastern Europe and elsewhere, have reached a point where the birthrate is too low to sustain a natural increase in population. Even in the US, which has the highest birthrate among the Western nations, the total fertility rate is marginally too low for full replacement without immigration, though immigration from Mexico and elsewhere will keep the US population increasing for some time to come. In Australasia, Canada, Europe, Japan, and South Korea, the fertility rate is now at well under replacement levels.
Despite the policy panic of the past few years, this is good news, as Paul and Anne Erlich point out in a recent article in New Scientist (30 September 2006). Declining population growth in resource-hungry developed nations - or better still an underlying population shrinkage once the effect of immigration is factored out - is cause for rejoicing, and policies to reverse the trend through such methods as baby bonuses are misguided. The declining birthrate shows that men and women have embraced the freedom to opt out of having large families, or out of having children at all, which is good news in itself: this new-found freedom is not proving illusory. There will also be good consequences for a planet that undoubtedly has a limited carrying capacity for large animals like us, especially when these large animals demand significant resources for the lifestyles that we've all become accustomed to in the West.
For countries that have experienced the demographic transition to much lower birthrates, the outcome will be a significant restructuring of the age profile, with relatively more middle-aged and older people and relatively fewer children, teenagers, and younger adults. That may have some disadvantages, but it will also have advantages. The fear that there will be an inadequate economic base to fund age pensions should be put in perspective by a whole raft of countervailing factors:
* Being older is not what it used to be. Even without dramatic breakthroughs in age retardation technology, people are staying active, robust, and healthy until well into what was once old age. Admittedly, this does suggest that existing policies according to which 65 is "retiring age" need to be rethought. Those policies were never intended to provide us all with a decades-long taxpayer-funded vacation, but were introduced in the nineteenth century at a time when someone aged 65 would have had few years to live after a lifetime of hard work. In the new world of the twenty-first century, many people who live to a ripe old age will still be active and interested enough to work (at least part-time) until well beyond what is currently thought of as retirement age. In fact, here in the privileged West, we need to stop thinking of 65, or even 75, as old.
* It is possible that research such as that being conducted by Jay Olshansky and his colleagues will produce some addition to the maximum and average life spans, but if this involves an absolute, or even relative, compression of morbidity then there will be overall economic benefits rather than costs.
* More speculative and radical life extension proposals would have even greater benefits if they eliminated the ongoing frailty and chronic sickness that many people who live deep into old age have always had to put up with. However, the one thing we must do is avoid policies that are based on extending periods of morbidity. The focus must be on extending robustness and health. Government funding of medical research should reflect this.
* A more top-heavy age profile is likely to produce a continuing decline in acts of crime and violence, with their attendant social costs.
* Any additional costs to healthcare and pensions will be offset at least in part by dramatically reduced costs in the public support that would otherwise have been needed for government programs aimed at children in their dependent years.
* In any event, as productive technology advances there is plenty of economic wealth to go around, some of it to be redistributed into pensions if need be. Think of all those industrial robots we've built, and keep building, as an enthusiastic slave class with none of the obvious moral and prudential downside of keeping real slaves. All that is required here is the political will to redistribute wealth, when necessary to achieve our aims, as well as creating it.
Humanity faces many serious challenges in the coming century and beyond, including the ongoing moral catastrophe of global disease and poverty; the environmental, human, and economic cost of global warming; and the likely proliferation of massively destructive weapons to fanatical regimes, organisations, and individuals. Properly handled, however, the decline in fertility in Western, and many other, nations is not part of the problem. It is part of the solution.