Is Britain's population really shrinking? And if so, should it bother us?

Demographers may sigh that the public is unable to distinguish between the total number of babies born, the birth rate and the fertility rate, but they can hardly expect that people with a hundred and one more pressing matters to attend to will be interested in the nuances of demographic terminology. Journalists, meanwhile, are also too busy to pay an awful lot of attention to the fine details – and often get birth rates and fertility rates muddled.

Nevertheless, to understand the significance of the latest data for England and Wales from the Office of National Statistics – data which has managed to grab a headline or two – it is worth pausing to distinguish between some related but subtly different concepts. The total number of babies born tells us little about a society’s proclivities until we know the total size of the population. Babies born per thousand of the population, meanwhile, is interesting, but it is bound to be skewed depending on the age of the population. Most revealing is the fertility rate – the number of children born per woman. This can ultimately only be known of a cohort when its fertility  is over, say by the age of fifty. ‘Completed fertility’ of women born in the 1940s can, now, be more or less definitively compared with those born in the 1960s. But this is a very backward-looking measure.

A more contemporary picture is shown by looking at the total number of women of fertile age in a given period, looking at the number of children those women bore in that period, and then calculating how many children the average woman would have if she followed that pattern. So, for example, if there were a million women aged 15-50 in the general population, and if in a given year they had between them a hundred thousand babies, then you could reckon that, if that year were typical, the average woman would have one tenth of a baby each of her fertile years, so one baby per decade, and 3.5 babies over a fertile lifetime.

So much for the theory. What does the latest data tell us about the practice in England and Wales? First, there were around 657,000 babies born in 2018, down more than 3% on 2017 and almost 10% on 2012. The year I was born, 1964, there was a bumper crop of 876,000 babies. But this drop-off understates the story, because back in 1964 the overall population was much smaller. Back then, at the final flurry of the post-war baby boom, the birth rate was more than eighteen per thousand; today it is just above eleven; it has never been lower since records began in 1938, which means it has probably not been lower for thousands of years. Most significantly, the fertility rate has fallen to 1.7 children per woman, one of the lowest rates ever recorded in Britain.

The implications of this are not quite as simple as the headlines might indicate. One is tempted to take up the stance of Tevyah the Milk from Fiddler on the Roof. On the one hand, one year’s data is just that, one year’s data. On the other hand, these statistics are consistent with long term trends and do not tend to dart about randomly. Back to the first hand, the fertility rate for England and Wales has moved within a fairly narrow band of around 1.6 to around 1.95 for getting on for half a century (well, since 1974 to be precise) and is still within that band. Back to the second hand, we had seen a meaningful movement towards the top of this band during the early years of the current century and are now seeing a consistent move towards the bottom of it. Once again to the first hand, there are many countries with significantly lower fertility rates than ours; to name but a few, Germany (1.6), Spain (1.3) and Japan (1.4). But on the second hand, this provides only the consolations of Schadenfreude.

All of this good news/bad news assumes that the higher a fertility rate, the better. That is clearly wrong for poor countries with burgeoning populations, trying to bring their growth rates down. That would include just about everywhere in sub-Saharan Africa (except perhaps for South Africa). But even in the UK, if Harry and Meghan are to be believed, we should all be aiming to reproduce a bit less to save the planet.

Ultimately, however, a population which is not prepared to reproduce is going to go out of business. There may well be more instances of women having problems conceiving these days, but on the whole, low levels of childbearing is about personal choice, not biological mischance.

With a mixture of immigration and assimilation (the former easy to pull off for a rich country, the latter more difficult), a nation can keep going at sub-replacement fertility (that is, fertility rates below around 2.1) but in the longer run, immigration is no panacea. First, the societies from which we recruit our immigrants are going through their own demographic transitions; Polish women today have less than one and a half children each. Second, where we recruit from higher-fertility populations (such as Pakistan or India), we find a strong tendency for immigrant fertility rates to converge quite closely with those of the local population within a generation or two.

A fertility rate of 1.7 for a single year is not a calamity, but a fertility rate consistently below replacement level for nearly half a century is. Where it has been far below for a long time, such as in Japan, we see the results; a shrinking workforce, depopulated villages and even suburbs, a fiscal crisis as government pays pensions from debt rather than taxes raised from workers. The bell tolls for us too, even if for now its chimes are heard more distantly.

What to do? The resort is always to government and policy and there are measures which governments can take which will help on the margin. But in the end it is down to the men and women in a society as to whether they value the joys which parenthood brings over the sacrifices it necessitates and whether they see themselves as part of a collective story which they wish to continue. The answer to this question for England and Wales, based on last week’s data is – not much.