A latest demographic analysis jointly completed by researchers from the Max Planck Institute for Demographic Research in Germany, the United Nations Population Division, and the University of Oslo shows that with the long-term imbalance in sex ratios and changes in mortality, the differences in fertility patterns between men and women around the world are experiencing a structural turning point: starting around 2024, the total fertility rate of women globally has exceeded that of men as a whole for the first time, and the proportion of men without children has increased significantly.
The study pointed out that traditional demographic statistics usually use the "total female fertility rate" as the standard, that is, assuming that the current fertility level of each age group remains unchanged during a woman's lifetime, how many children will she have on average. But in practice, the same questions are rarely asked: how many children the average man will have in his lifetime, and how men's "total fertility rate" differs from women's. To fill this gap, the research team used data from the United Nations' World Population Prospects, supplemented by indirect population measurement and statistical methods, to conduct a systematic analysis of the historical changes and future trends in male and female fertility rates in different regions of the world.
Henrik-Alexander Schubert, one of the lead authors of the study and a researcher at the Max Planck Institute for Demographic Research, said that a "reversal" is occurring at the global level: under a long-term pattern of slightly higher total male fertility rates, in recent years it has gradually transitioned to a situation of higher total female fertility rates. This reversal will take shape on a global scale around 2024. The key mechanism behind this is the increase in the proportion of males in the population, and a series of related demographic processes, including the decline in overall mortality, the narrowing of the mortality gap between men and women, and the long-standing phenomenon of sex-selective abortion in some countries, which together maintain or even strengthen the "male-biased" gender structure from birth to adulthood.
However, the emergence of this "crossing point" in gender fertility rates does not occur simultaneously in all regions, but is closely related to the stage of demographic transition in each region. Research shows that in most countries in Europe and North America, the period in which male fertility rates were higher than female fertility ended as early as the 1960s and 1970s, and has entered a new phase in which female fertility rates are relatively higher. Most countries in Latin America have only completed this transition in recent years, while many regions in Oceania, South America and Asia have only gradually crossed this node in recent years. In contrast, sub-Saharan Africa is expected to transition from high male fertility to high female fertility only before the end of this century due to stagnant decline in overall fertility and high mortality rates for a long time.
As the proportion of men in the population increases, the gap in total fertility rates between men and women continues to widen, a trend that brings new challenges at the social level. Schubert pointed out that the most immediate risk is concentrated on men who remain childless throughout their lives - relevant studies have shown that men who are childless are often associated with poorer health and are more likely to rely on professional care services in their later years, thus putting additional pressure on social security and medical systems. The research team warns that if sufficient attention is not paid to this gender gap and its cumulative consequences, the plight of childless men may also trigger a cultural backlash against gender equality and increase the risk of social tension and conflict.
In order to deal with this emerging structural problem, the study proposes several possible policy paths. First, strengthen women’s status in society and reduce or even end sex-selective abortion through legal and social advocacy to alleviate the gender imbalance in the population starting from birth. Second, expand educational and employment opportunities for single and childless men to improve their career prospects, thereby reducing their vulnerability to economic marginalization and recruitment by organized crime. Third, build a social support system for singles and childless groups, such as encouraging community interactions and "friendship networks", and providing them with more convenient access to assisted reproductive technology at the legal level, so that people who want to have children but lack a partner have more choices.
The research team emphasized that the "masculinization" of the population and the resulting gender reversal in fertility rates are the cumulative result of long-term population processes and are difficult to reverse through a single policy in the short term, but the negative impact on individuals and society can be reduced through targeted intervention. They call on policymakers to take the issue of male childlessness into consideration when formulating population, education and social policies, along with traditional reproductive support and gender equality issues. This study, titled "Masculinization of populations reverses sex differences in fertility," was published in the Proceedings of the National Academy of Sciences in April 2026.