In yesterdays’ opinion piece in The Guardian (February 10th), Guardian columnist Zoe Williams discusses the letter from the French Health Ministry to all 29 year old men and women reminding them to have children. Williams discusses the more profound issues at stake in this French move, quoting Professor Francois Gemenne, HEC Paris, who embeds this attempt to raise childbearing within modern politics as arising from the “(native) obsession with immigration and the fear of being replaced”.
It is impossible to ignore the heated political debate surrounding international migration, and the rhetoric being variously described as toxic, racist, divisive, destructive. I do not intend to take a political stance on international migration, but let’s look at the science, at the prevailing demography in here Great Britain, and the role that international migration could play in addressing this demography.
Key here is the question of population ageing. Population ageing is when the number and the proportion of people in a population over a certain age (often an assumed retirement age, or the state pension age) is increasing relative to the rest of the population. This demographic development is a combination of more people living longer lives and very low levels of childbearing[1]. So-called period life expectancies at birth in Great Britain stand at around 79 years for men and around 83 years for women compared with around 71 and 77 years respectively in the early 1980s. Today, the average number of live births per woman in Great Britain is around 1.4 – significantly below the magical 2.1 which is necessary for a population to replace itself in the long run, and down from the baby-boom level of 2.7 in 1947.
We must note, however, as far as these indicators are concerned, as with many other socio-economic and demographic indicators, there is a significant degree of inequality. Life expectancies in England in 2022-24 were 83.3 years for females and 79.4 years for males; in Northern Ireland they were 82.6 and 78.8 years respectively; in Wales 82.2 and 78.3 years respectively; and in Scotland 81.1 and 77.1 years respectively. In 2021-23, the lowest life expectancies in England were found in the Blackpool area, standing at 78.9 years for females and 73.1 years for males, while the highest were in the Hart area, standing at 86.5 years for females and 83.4 years for females . Likewise, levels of childbearing differ ranging from 1.28 in Scotland to 1.64 in Northern Ireland . The impact of population ageing will therefore vary accordingly between countries and even regions within those countries.
As a result of these demographic trends, there are concerns over the number and proportion of workers able to support any increases in dependency. Indeed in most high income countries, the ageing of our population has been an on-going process since the beginning of the continued decline in levels of childbearing towards the end of the 19th century in the so-called demographic transition, with concerns in the UK being raised in the immediate post-war period as the ageing scenarios became recognised in government reports[2]. And along with increasing fertility and retaining older workers, migration is seen as being able to ameliorate this.
Increasingly, international migration has played a role alongside the transition, preventing populations from declining during so-called baby-busts and softening the demographic challenges of population ageing. Given that generally speaking populations strive to reduce levels of mortality and efforts to influence levels of childbearing have been unsuccessful (one the exception being the one-child policy in China), international migration is in theory a useful demographic component which can be managed to address the challenges of population ageing, replacing those unborn children and supplying labour to the economy.
However, in many countries, the toxicity of the migration debate is based more on myths, fabrications and fallacies than on facts. In Great Britain, for example, the rhetoric around the boats – boatloads of irregular or illegal migrants crossing the Channel organised by people smugglers. Reports of people arriving across the Channel in small boats go back to the 1970s but numbers did not begin to increase until 2018, and from 2020, numbers increased rapidly to over 40,000 in 2022 and since. These numbers are, however, a drop in the ocean when compared with levels of regular migration, where net migration (immigration minus outmigration) which reached over 860,000 in 2023. But the footage of the boats being stopped in the Channel and reports of drownings should not impact on the demographic case for migration.
There are other key benefits from international migration. Immigrants boost local economies in several key ways. Their spending and investments create demand for goods and services, leading to increased job opportunities for local workers. Furthermore, immigrants often fill labour needs in sectors like service and healthcare, allowing native-born workers, particularly women, to participate more fully in the workforce, increasing overall productivity. Businesses respond to this influx of people by expanding and relocating, generating further investment and jobs. Finally, many immigrants are entrepreneurs themselves, launching businesses and generating even more employment for the local community.
Immigrants often take on jobs that are different from and supplementary to those of native workers, rather than directly competing with them. For instance, immigration meets the demand for certain manual and labour-intensive positions, allowing skilled native workers to concentrate on more complex roles, which in turn enhances their productivity and wages. Furthermore, a review of the existing research suggests that the effect of immigrants on the average wages of native workers is minimal.
In ageing societies, the influx of young workers alleviates the fiscal pressures on pension systems and assists in covering the medical expenses of retirees. Importantly, native populations typically exhibit a negative net fiscal balance during their youth and old age, while maintaining a positive fiscal balance during their working years. Since immigrants often arrive in the host country at the beginning of their working lives, they tend to generate a higher net positive fiscal impact.
Science can only provide the evidence to inform policy. The decision to use the evidence or to ignore it lies elsewhere with government. Otherwise, as Williams warns young couples “will be used as pawns in the Great Replacement narrative”.
[1] For example, Leeson, G.W. (2018) The Growth, Ageing and Urbanization of Our World, Journal of Population Ageing, Vol. 11 (2), pp. 107-115 and Leeson, G.W. (2025) Extreme population and individual ageing: drivers and implications, Monograph, Institute of Social Work and Ageing, the Autonomous University of Yucatan, Mexico.
[2] Phillips Report, 1948; Harper and Thane 1989 The Consolidation of ‘Old Age' as a Phase of Life, 1945–1965
Growing Old in the Twentieth Century; Harper, s. 2000 Ageing 2000—questions for the 21st century Ageing and Society 20:1
About the Author
George Leeson is a Professorial Fellow at the Institute of Population Ageing, where he co-ordinates the Latin American Research Network on Ageing (LARNA) and the Central and Eastern European Research Network on Ageing (EAST).
Opinions of the blogger is their own and not endorsed by the Institute
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