1.1. What if the conditions of 2024 persist ?

The changes observed since these projections were published do not match those of the baseline scenario, while remaining within the bounds of the ‘high’ and ‘low’ scenarios. This is not surprising, as all projections are inevitably challenged and sometimes contradicted by reality. The aim is not to foresee the future but to determine how it would look under different sets of conditions.

We made a new projection based on a ‘2024’ scenario which assumes that fertility remains stable at its 2024 level (1.62 children per woman rather than 1.8 as in the INSEE baseline scenario). Fertility may continue to fall in coming years, it may stabilize, as in some European countries, or move up again, as it did after the period 1993–1994 when it dipped to a low of 1.68 children per woman. The assumption that fertility will remain at its current level represents a compromise between several possibilities.

Thanks to a sharp decrease in mortality between 2022 and 2023, life expectancy recovered to the level recorded in 2019 before the COVID-19 pandemic, and even exceeded it. Life expectancy continued to increase in 2024, but more slowly (Figure 3). The progress observed in the last few years is ­finally below that of INSEE’s baseline scenario and is closer to the low assumption, for women especially. For the ‘2024’ scenario, we apply this low assumption for female life expectancy improvement, and an intermediate assumption for males (see online appendix ¹).

For net migration, we assume a stable level of 152,000 per year (equal numbers of males and females), the provisional estimate for 2024, rather than 70,000 as chosen for the 2021 baseline scenario on the basis of trends observed in the 2000s.

1.2. Natural increase continues to fall…

The 2024 projection up to 2070 sees a decrease in births and a rise in deaths, with natural increase becoming negative in 2027 (Figure 1). From then on, the deficit widens steadily, reaching –256,000 by around 2060 before stabilizing. The increase in deaths corresponds to the gradual extinction of the large baby-boom cohorts as they reach advanced ages. Meanwhile, births increase slightly in the next 2 decades as the large cohorts born around 2010 reach reproductive age (Figure 4).

1.3. … but population growth continues for 2 more decades

Although natural increase will soon become negative, the 2024 scenario projects that the French population will increase to 70 million in the 2040s before declining to 68 million in 2070 (Figure 2). This projection is very similar to that of INSEE’s 2021 baseline scenario, although different factors are at play, with higher net migration in the 2024 scenario making up for lower fertility and the slower increase in life expectancy. The ­population ages substantially and in a similar manner under both scenarios, with slightly more males and slightly fewer children and older women in 2070 in the 2024 scenario than in the baseline scenario (see detailed projections in the online appendix).

1.4. A stalling of progress in life expectancy

Let us examine why progress in life expectancy is projected to stall under the 2024 scenario.

There were 646,000 deaths in France in 2024 [1], 7,000 more than in 2023 (639,000 deaths) (Table 1). This rise is due partly to demographic growth and ageing, which increase the number of older adults in the population. Calculating life expectancy provides a means to eliminate components of mortality linked to variations in population size and age distribution, so that only the risk of dying is taken into account. Life expectancy at birth increased by 0.1 years for males in 2024 and stagnated for females, reaching 80.0 years for males and 85.6 years for females versus 79.9 years and 85.6 years, respectively, in 2023 (Table 1 and Figure 3). As mentioned above, life expectancy increased sharply between 2022 and 2023, by 0.6 years for males and 0.5 years for females.²

Viewed in relation to longer-term trends, the recent annual life expectancy fluctuations show that progress is slowing (Figure 3). For what reason?

1.5. Why was life expectancy increasing up to now?

Since the mid-20th century, life expectancy at birth has increased by around 3 months each year in France, rising from 66.4 years for both sexes in 1950 to 82.8 years in 2024. This upward trend is due mainly to progress in reducing adult mortality, especially at advanced ages when an increasing number of deaths occur. Child mortality, whose decline was a key driver of life expectancy increase from the late 18th to the mid-20th centuries, has practically no effect today, as it has now reached an extremely low level.³

In the mid-20th century, it was the decline in infectious disease mortality that drove the rapid increase in life expectancy. But the share of these diseases in overall mortality has fallen sharply, so any additional gains resulting from their further decline will be small.

1.6. A decline in cardiovascular and cancer mortality

Cardiovascular diseases and cancer are now the leading causes of death (Figure 5). Progress in combating these diseases has reduced mortality levels since the 1970s and driven the steady increase in life expectancy.

Mortality from diseases of the heart and circulatory system has plummeted in the last half century thanks to the ‘cardiovascular revolution’, with major advances in the prevention and management of these pathologies [4]. Cancer mortality, which increased between 1925 and 1995, is now declining thanks to earlier diagnosis, improved treatments, and a reduction in risk behaviours such as smoking.

The slower increase in life expectancy over the last decade is perhaps a sign that the benefits of the cardiovascular revolution have now reached a plateau and that future progress may depend increasingly on the fight against cancers, now the leading cause of death. So far, the benefits of cancer reduction in terms of life expectancy have been less spectacular than those linked to the cardiovascular revolution. Male cancer mortality has fallen substantially, and the decrease is ongoing. Female cancer mortality is lower but has declined more slowly in recent years due to the rise in smoking-related cancers. Many women born in the 1930s were smokers between the 1950s and 1980s and are suffering the consequences several decades later [4].

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The future is not written in stone, and the 2024 scenario projection is just one of many possible developments. Fertility may continue to decline, net migration may rise or fall, and new mortality crises may occur. This projection nonetheless shows that if fertility and net migration remain stable after 2024 and life expectancy continues to rise, the population of France should not start to fall within the next 2 decades. Until then, positive net migration should more than offset future negative natural increase.