June 17, 2026 | News | Award
Henrik-Alexander Schubert receives Otto Hahn Medal
On June 17, MPIDR researcher Henrik-Alexander Schubert was awarded the Otto Hahn Medal in Frankfurt for his doctoral thesis on “The fertility puzzle. Trends and patterns of male and female fertility”. The Medal was presented at the Annual Meeting of the Max Planck Society, during the meeting of the Human Sciences Section in Frankfurt. In his thesis, Henrik investigated low fertility and its determinants. It makes major contributions to our understanding of current trends in fertility, and it does so with the highest methodological rigor.
Otto Hahn Medal recipient Henrik-Alexander Schubert (center) with Stefan Vogenauer (left), Director of the Max Planck Institute for Legal History and Legal Theory, and Christian Doeller (right), Vice President of the Max Planck Society. © David Ausserhofer / MPG
In his dissertation, Henrik explores trends in fertility and provides fascinating insights. Total fertility rates plummeted in the United States and the Nordic countries during the 2010s. This decline is an intriguing empirical puzzle because it occurred across regions, social groups, and different welfare state contexts, making it difficult to understand.
"The truly distinguishing feature of Henrik’s research is the ability to look at old things from a novel perspective. This is true throughout his thesis, and is well illustrated by his analysis of childlessness and regional male-female imbalances. Prior work has largely missed the effect that male-female imbalance – or ‘missing women’ – have on male childlessness, but when looked at the right regional scale, the effect becomes clear and strong," explains Mikko Myrskylä, Director of the MPIDR and head of the Social Demography Department.
Using large-scale population registry data from various high-income countries, Henrik examined these recent fertility declines and identified the driving factors. Throughout the dissertation, attention is given to the contributions of both – men and women. Additionally, subnational designs are employed to address the limitations of cross-country comparisons. He concludes that the drivers of recent fertility declines are multifactorial, pertaining to social, cultural, economic, structural, and biological factors.
His supervisor Christiaan Monden at the University of Oxford says about him: “From the beginning, Henrik showed a remarkable combination of independence, ambition, and collegiality. He was full of ideas, eager to tackle difficult questions, and never intimidated by complex problems. At the same time, he listened carefully to suggestions and was generous in supporting the work of fellow students and collaborators. These qualities shine through clearly in his thesis, which combines intellectual creativity with methodological rigor.”
Essential takeaways of the dissertation
- Henrik looked into factors driving fertility change in the 21st century and showed the relevance of structural and cultural factors. As a structural factor, he zoomed into economic development and regional partner markets. Both have undergone noticeable shifts in the recent decades with implications for fertility. As a cultural factor, his research revealed the role of accelerations in secularization in the 21st century that have reduced fertility.
- He showed once more that fertility measured for men deviates substantially from fertility measured for women. Henrik looked at the mean number of children and levels of childlessness. In high-income countries, fertility is lower and childlessness is higher among men compared to women.
- He made several methodological innovations such as approaches to establish cut-offs for substantial sex differences in fertility and a predictive score of couple’s fecundity, indicating a high or low biological capacity to have children.
"Henrik submitted a truly outstanding thesis. It develops a novel perspective on one of the most pressing topics in many countries, and it innovates both conceptually and methodologically. Henrik continues to impress us as a postdoctoral researcher," explains Christian Dudel, leader of the research group Labor Demography at MPIDR.
“I am thrilled and honored to receive the Otto Hahn Medal. The research environment at the MPIDR and the Nuffield College were the perfect setting in which to follow my curiosity and pursue my interests. I was extremely fortunate to have three supervisors — Christian, Christiaan, and Mikko — who encouraged, challenged, and supported me throughout this endeavor. I am really standing on the shoulders of three giants.”
Henrik completed his Ph.D. at the University of Oxford and was part of the International Max Planck Research School for Population, Health and Data Science (IMPRS-PHDS), a three-year doctoral program that merges demography, epidemiology, and data science. The thesis was supervised by Christian Dudel, Christiaan Monden, Mikko Myrskylä. He was a student at the Nuffield College, Oxford.
Publications from the dissertation
Two chapters of his dissertation have just been published in scientific journals. The joint paper with Vegard Skirbekk and Jessica Nisén, “Secularization and low fertility”, investigates how recent accelerations in secularization may have contributed to the fertility declines in Finland. The paper “Subnational birth squeezes” is forthcoming in Demography and investigates sex differences in the total fertility rate at the subnational level and provides methodological approaches to determine significant differences, which are called birth squeezes.
Otto Hahn Medal
Each year, the Max Planck Society awards the Otto Hahn Medal to a young scientist for outstanding scientific achievements, usually in the context of a doctoral thesis. The award is intended to motivate highly talented young scientists to pursue an academic or research career. Since 1978, more than 850 scientists and researchers have received the Otto Hahn Medal. The award is presented during the General Assembly of the following year.
Patrick Cramer, President of the Max Planck Society, with the winners of the Otto Hahn Medal. © David Ausserhofer / MPG