Abstract: Insight into the future of the world population is key for policy planning. At present, several organizations engage in developing global long-term population projections and provide varied results in terms of projected population size and structures. This diversity demonstrates that there is a need to reflect on the ingredients that feed into the projections. This Special PAA Session presents findings from The Global Demography Survey, which asked experts in demography belonging to population associations from around the globe to assess the validity and relevance of alternative arguments about the forces that could shape future fertility, mortality, and migration trends in the country of their choice. The results show that experts almost unanimously support the roles played by urbanization, reductions in child mortality, greater educational attainment, and employment opportunities for women in decreasing fertility in high-fertility countries. At the same time, life expectancy is expected to continue increasing across world regions, with the most significant improvements projected by experts in current 'low mortality' countries. Experts on migration mostly agree that climate change will lead to a rise in immigration. However, there is less agreement on the forces driving emigration. As a broad conclusion, the expert opinions seem to indicate that demographic challenges of the future do not necessarily have demographic solutions, and will instead necessitate improved adaptive capacities among all societies. In the session, we will reflect on how the findings can shape future global population projections.

Session plan: The survey was a joint project by the European Commission’s Joint Research Centre, the Institute for Applied Systems Analysis, and the United Nations Population Division. The special session will feature four presentations providing an analysis of the survey results concerning experts’ opinions on the drivers and future trajectories of the components of demographic change (fertility, mortality, and migration) (1), as well as on population policies (2). In the second part, the United Nations and IIASA will reflect on the findings in relation to the methodologies and assumptions supporting their global population projections (3) (4). The session builds on the descriptive findings published in the Technical Report “Global Demography Expert Survey on the Drivers and Consequences of Demographic Change”. The survey results are considered in the context of demographic foresight, which involves anticipating future population shifts, to inform policymaking.

Chair: Nicholas Gailey


Results from the 2023 Expert Survey on Future Drivers of Population Change
P. Ueffing; European Commission Joint Research Centre.

Expert Opinion and the United Nations World Population Prospects
M. Wheldon; United Nations Population Division.

Expert Opinion and the IIASA Projections
A. Goujon; International Institute for Applied Systems Analysis.

The Global Demographic Convergence: A Multi-Scale Analysis
P. Eloundou-Enyegue; Cornell University.