Men start having fewer children than women globally. Why? And what does this mean?
Fertility rates are up across the world, but a new demographic analysis points to a less obvious change: For the first time, men are expected to have, on average, fewer children than women over a lifetime.
According to the new modeling study, in PNAS on April 20, the male total fertility rate fell below the female one in 2024.
This indicator, known by the acronym TFR, has been used to measure women’s fertility. Among these, the global average went from 4.9 children per woman in 1952 to around 2.3 in 2023. In the case of men, researchers had to resort to indirect estimates, based on previously estimated population data.
For much of recent history, men had, on average, slightly more children than women. Now, it appears that this difference has disappeared and reversed.
The explanation, according to the authors, is not mainly in a cultural or behavioral change, but in a demographic transformation: There are now more men surviving into adulthood and the reproductive period.
Historically, around 105 boys were born for every 100 girls, but this difference tended to decrease throughout life, due to the higher male mortalityassociated with factors such as illness, diet, excessive alcohol or tobacco consumption and other risks. With the improvement of living conditions and survival, this male surplus stopped disappearing so soon and began to be reflected in the adult population.
The result is simple, from a statistical point of view: with more men than women of reproductive age, the average number of children per man falls. It doesn’t necessarily mean that men are individually choosing to have fewer children than before; it means there are more men sharing the same potential number of births.
The trend has been visible for decades in North America and Europe, but is now becoming more relevant in Asia as well. In some Asian countries, such as China or Vietnam, the imbalance is worsened by prenatal selection depending on sex, which raised the birth rate to around 110 boys for every 100 girls.
In practice, this could mean an increase in the proportion of childless men, especially in regions where the imbalance between the sexes is greater. In the long term, the phenomenon may have consequences important social issues, including more elderly men without direct family support and greater pressure on social protection and elderly care systems, warn the authors, cited by .
