Ryohei Mogi | Demographer
Ryohei Mogi
Ph.D. in Demography
Pompeu Fabra University, Department of Political and Social Science (Spain)
I am a demographer who bridge scientific research with real-world action.
My mission is to turn evidence into action to tackle low fertility, through research and collaboration with policymakers, the media, and both public and private sectors.
Background
I received my Ph.D. in Demography from the Centre for Demographic Studies, Universitat Autònoma de Barcelona.
I then worked as a Research Fellow at the Department of Sociology, University of Oxford, and as an Assistant Professor at the Interdisciplinary Centre on Population Dynamics, University of Southern Denmark.
I am currently based at Pompeu Fabra University in Barcelona.
My expertise lies in comparative demographic research, analysing fertility and family change.
How I work with partners
Alongside academic research, I actively engage with policymakers, media, and the public and private sectors.
Here are the main ways I collaborate:
- Advisory & consulting: Supporting policymakers and organisations with evidence-based guidance. This includes survey design, analysis of fertility and marriage trends, and the creation of data dashboards
- Public speaking & lectures: Keynotes, seminars, and talks on fertility and population issues
- Writing & media: Articles, commentary, and fact-checking for newspapers, magazines, and international media outlets
Invited Talks (Selected)
- 06/03/2024. Challenges of dataviz and the reactions from the internet audience to our study. RAS seminar, Office for National Statistics, the UK.
At universities: Universidad Nacional de Educación a Distancia (Spain), Charles University (Czechia), London School of Hygiene and Tropical Medicine, Princeton University, Macquarie University (Australia)
Media Appearances & Interviews (Selected)

- Todo por hacer. Radio 5, rtve. 30/09/2025. (In Spanish)
- What superstition tells us about humanity. Financial Times. 25/09/2025. (In English)
- New mothers are getting older - but in East Jutland there is still a preponderance of teenage mothers. TV2 Østjylland. 05/04/2023. (In Danish)
- Over-45s in Denmark giving birth more than teens. The Copenhagen Post. 04/04/2023. (In English)
- Fertility is now a global challenge - report exposes one important truth. Nyheder TV2. 04/04/2023. (In Danish)
- Two numbers say a lot about how we have children today: Fertility expert calls it both a “triumph and an accident”. Berlingske. 03/04/2023. (In Danish)
My 4 missions as a demographer

Follow me
Blog posts on low fertility and demographic change, written for a broad audience and for policy insights
news
| Sep 30, 2025 | New media interview Todo por hacer in Radio 5, rtve. |
|---|---|
| Sep 25, 2025 | New media article What superstition tells us about humanity in Financial Times. |
| Aug 5, 2025 | New publication Exposure to non-partnership and fertility desires among childless population in Japan in Social Forces. |
| Sep 10, 2024 | New publication Lowest low fertility in Spain: Insights from the 2018 Spanish Fertility Survey in Demographic Research. |
| Jun 7, 2024 | New publication Employment conditions and non-coresidential partnership in very-low fertility countries: Italy and Japan in Journal of Family Research. |