The year 2025 will have marked the end of the natural growth of the French population: births are now lower than deaths, both because the number of children is decreasing and because the baby boom generation is starting to reach the end of its life. The country’s demographic growth therefore now depends, as in almost all European countries, on its net migration.
Some observers of these trends raise the question of the sustainability of the French social system, which would be based on assets and would be doomed to disappear with their decline. Without engaging in a discussion on the financing of national solidarity, which we could consider, for example, also based on capital income and not only on work (and therefore the number of active workers), we propose here to see whether the future of the French population is predictable or not and how.
Projection models and uncertainties
Concerning the future of populations, it is customary to propose what we call population projections. This involves producing models, which will estimate population changes over time, taking into account the number and age structure of people present today, and varying birth rates, mortality, immigration and emigration according to specific scenarios. This is the “by component” method. The further we move away from the present day, the more the uncertainty increases and the more the different scenarios diverge.
National and international statistical and demographic institutes undertake this exercise regularly. This makes it possible to provide quantified data to political decision-makers. On a global scale, the United Nations (UN) regularly publishes projections for all countries; in Austria, the Wittgenstein Center does the same with other parameters and by also offering projections on education.
The exercise of looking at past projections is always painful, since it shows the mistakes made.
In France, the National Institute of Statistics and Economic Studies (Insee) regularly produces projections at national, regional and local scale. Locally, it is the Omphale model which is mobilized. This is a model that uses local data from a given moment to project changes in the population over several decades. Omphale’s latest revision dates from 2022, is based on 2018 data and projects out to 2070.
The exercise of looking at past projections is always painful, since it shows the mistakes made. In France, since the 1970s, this has most often been an underestimation of the population, linked to assumptions of low fertility (which did not prove to be accurate), a cessation of migratory flows (which did not take place) and low growth in life expectancy (which was ultimately greater).
Some scenarios for 2070
To envisage the future of the population, we must therefore ask ourselves the question of what will happen in terms of birth rates, mortality and international migrations. The birth rate corresponds to the number of births observed. It therefore depends on the one hand on the number of women of childbearing age, which is quite easy to know, since, according to INSEE, there are nearly 14.7 million women aged 15 to 49 – and even partly to be expected.
We therefore know what the situation is for the next fifteen to twenty years, since we can count girls aged 0 to 15: there are a little less than 5.5 million. On the other hand, the birth rate also depends on fertility (how many children women have). This second element is subject to more precautions, because its determinants are difficult to predict. Thus, the recent drop in French fertility, although it had been envisaged by some demographers, had not been correctly anticipated.
Outside of periods of health crisis or war, mortality is an element whose evolution is fairly stable. By knowing the age structure of the population, we can make fairly realistic mortality forecasts. The fact remains that major accidents can happen, such as the outbreak of an epidemic.
We can nevertheless make hypotheses about the improvement in lifespan, since life expectancy continues to increase even today (the drop in tobacco consumption, particularly among young people, is good news), or about stagnation, or even a drop in it (for example in connection with the increase in sedentary lifestyle).
Migration movements (immigration and emigration) are also difficult to predict, since they depend on the one hand on individual decisions, but also on economic and political, and even environmental, contexts on the other hand. For example, the war in Syria or that in Ukraine caused an unexpected influx of refugees into the European Union. Nevertheless, we see that migratory flows in France remain relatively stable over time.
It is therefore with simple to understand and explainable scenarios that INSEE can offer projections for the years to come. On June 8, INSEE proposed its vision until 2070.
These projections remind us that, depending on the scenarios, after almost forty years, the French population could be 55 million or 78 million people, compared to 69 million today. However, many scenarios envisage a shift towards decline at the end of the 2030 decade.
To fully understand the issues surrounding the composition of the population, INSEE offers a dedicated online tool to explore the effects of different scenarios, as well as a variation at the regional and departmental level. We can consider them realistic, if we do not forget the uncertainty linked to this exercise.
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The difficulty of local estimates
If we wish to consider the future of populations in a more detailed manner, at the scale of municipal territories for example, it becomes more complicated to implement projections. Indeed, if natural population movements remain predictable to the same extent as on a larger scale, migratory movements are more difficult to take into account.
On the one hand, we cannot rely on the flows observed in the past to envisage those to come. A territory can attract at a given moment, then no longer attract later, or be saturated and no longer able to welcome new inhabitants. On the other hand, local migrations are also linked to the availability or otherwise of housing. Changes in construction policies can have strong, completely unpredictable local impacts.
Stopping immigration: an acceleration of aging
Human beings have always sought to protect themselves and demographic projections are part of the tools for understanding the future. They can nevertheless sometimes frighten, although they only constitute possible futures, on which it is partly possible to act and which should above all lead us to anticipate.
In all likelihood, the natural dynamics of the population should not start to increase again for several decades. Migration flows, for their part, are subject to more hazards, but we can envisage that they will not radically change the situation in terms of population growth. If they continue like this, they will offer a form of cushioning to the changes taking place.
We must also warn of the consequences of stopping immigration, which would accelerate both the country’s entry into demographic decline, but also its aging and its consequences.
As for worrying about the possible consequences of these demographic changes, yes, it may seem necessary. But it is not so much a question of fearing a disillusioning future as of adapting to current and future changes, for example by taking better account of demography and its consequences in the necessary reorientation of social and economic policies.
