Although the government refuses to discuss migration numbers, the issue is likely to be forced up the agenda. This short article provides some of the background that should be required for an informed debate. Working from official projections, I have quantified the impact of immigration on the total population of Britain and on its composition.
The chart shows projections of the future population of Britain under various assumptions about net migration. With one exception, all projections are taken from the website of the government actuary's department. The curve labelled "zero net migration" shows what would happen if there were no net inflow of people into the country—if as many people left each year as entered. The high migration curve shows what would happen if net immigration were to average 205,000 a year. The curve labelled "extrapolation" is my own estimate of future population if net immigration were to average 223,000 a year. This is the rate actually observed in 2004, the latest year for which figures are available.
With zero net migration, and the assumed birth and death rates, population would rise slightly for a time and then fall away at an accelerating pace. With net migration of 85,000 a year, population would increase for some decades and then stabilise at around 65m towards the end of the century. With net migration at the rate of 223,000 a year, the population would reach 74m by 2051 and continue rising strongly thereafter. This figure—74m—is 16m greater than the 2051 population figure under the zero net migration assumption. Part of the difference is explained by the inflow of migrants and part of it by the fact that immigration would increase the number of children born in this country.
The above figures understate the impact of migration on the social composition of Britain, because they conceal the fact that British citizens are leaving the country at the same time as foreigners are arriving. In 2004, there was a net outflow of 129,100 British-born individuals and a net inflow of 351,700 foreign-born individuals. If sustained, this would mean that over the period 2006-51 there would be a net outflow of 5.8m British-born individuals and a net inflow of 15.8m foreign-born individuals.
Predicting immigration is difficult since long-run trends are often masked by short-run fluctuations. There has recently been an upsurge in immigration from eastern Europe following EU enlargement. As conditions in eastern Europe improve, this flow may eventually reverse itself as immigrants return home to take up jobs. However, unless blocked by the government, there will be a new inflow when Bulgaria and Romania join the EU next year as planned, and further ahead there may be a much greater influx if Turkey joins. There is also a rising trend of immigration from Africa and south Asia. In view of these diverse pressures, it seems likely that immigration is on an upward trend. In the absence of new measures to contain the flow, the average rate of net migration is likely in future to exceed the figure of 223,000 recorded in 2004.
There is another point to consider. The projections upon which my estimates are based assume that immigrants have the same fertility as the existing population. This is false. For example, in 2001 the total fertility rates of women born in Bangladesh and Pakistan were 3.9 and 4.7 respectively, as compared to 1.6 for women born in Britain. Most immigrant groups do not have so many children, but even so, the overall total fertility rate for women in Britain born overseas was 2.2. When such discrepancies are taken into account, the eventual impact of a given rate of immigration is even larger than our projections imply.
In the absence of new measures to reduce the inflow from overseas, the cumulative impact of immigration on the size and composition of the British population will be huge. A majority of the population already believe that immigration is excessive and want it reduced. There are also those who believe that Britain should welcome mass immigration for the economic and social benefits which they believe it will bring to the local population. Others argue that there is nothing we can do to contain it, so we may as well accept it. Even if we could cut back immigration, the price in terms of human rights would be too high.
My own view is that the present scale of immigration is excessive. This view is not based on hostility to immigrants. On the contrary, I recognise the contribution that many of them make to British society and I frequently admire their work ethic and personal values. I also believe that we have a moral responsibility to outsiders who are less fortunate than ourselves. However, like many of my fellow citizens, I am concerned about the impact on British society of mass immigration. More important, as a democrat, I believe that there should be informed debate about what is happening. This note may help to inform such a debate.