Population Association of America — 2024 Annual Meeting
The 2024 PAA Annual Meeting brought together more than 2,000 demographers, economists, sociologists, and public health researchers for four days of sessions on the science of human population. Held at Columbus Convention Center, it served as the first major gathering where researchers could engage with the freshly released UN World Population Prospects 2024 data in a live academic setting.
About the Population Association of America
Founded in 1931, the Population Association of America is the leading scientific membership organisation for population researchers in the United States and one of the most influential in the world. Its annual meeting rotates across US cities and typically draws researchers from over 50 countries. Sessions range from methodological workshops to policy-relevant plenaries, with thousands of submitted papers peer-reviewed and accepted each year. The PAA also publishes Demography, one of the discipline's flagship journals.
Key themes at PAA 2024
Fertility decline and its limits
Multiple sessions examined the continued fall in total fertility rates across virtually every world region. A central question running through the conference: is the decline in sub-Saharan Africa accelerating faster than the UN's median projections assume? Researchers from the Institute for Health Metrics and Evaluation (IHME) presented findings from their alternative fertility model, which had recently appeared in The Lancet, projecting global TFR falling to around 1.6 by 2100. The debate between the IHME and UN approaches drew packed rooms.
Country-level sessions highlighted South Korea's record-low TFR of 0.72 in 2023 and the policy responses being trialled — cash transfers, childcare subsidies, extended parental leave — with mixed evidence on effectiveness. Japan and several Southern European countries presented updates on their own below-1.5 trajectories and demographic futures. Our World in Data maintains the global TFR dataset underlying many of these analyses.
Rapid ageing in East Asia and Europe
The consequences of decades of low fertility were a recurring theme. Sessions on population ageing covered the structural pressures on pension and healthcare systems, the rise in old-age dependency ratios, and the phenomenon of "super-ageing" societies — defined as those where more than 21% of the population is over 65. Japan, South Korea, and several European countries already meet this threshold. Researchers presented projections showing China crossing it before 2035.
A plenary session examined the relationship between ageing and labour force participation, drawing on data from the ILO labour statistics database and national surveys. The consensus: without significant immigration or dramatic increases in older-worker participation rates, shrinking working-age populations will structurally constrain economic growth in high-income ageing countries through mid-century.
Migration as a demographic stabiliser
International migration featured prominently as the mechanism through which countries with below-replacement fertility maintain population size and workforce capacity. Sessions analysed the record flows of 2022–2023, using data from the IOM World Migration Report 2024 and national administrative records. Researchers examined both labour migration (filling gaps in aged-care, healthcare, and construction) and displacement-driven flows from climate-affected and conflict regions. The net migration metric and its limitations for tracking these complex flows was discussed in multiple methodology sessions.
UN WPP 2024 data: first academic reactions
The UN World Population Prospects 2024 had been released just months before PAA, and several sessions served as its first systematic academic review. Demographers noted revisions to historical estimates for several African and Asian countries, updated mortality assumptions reflecting COVID-19's lasting impact on life expectancy trajectories, and revised fertility schedules for countries with newly available survey data. The medium-variant projection still places peak population at around 10.4 billion in the 2080s — a figure that generated debate given the IHME's lower estimate.
Methods: small-area estimation and probabilistic projections
A growing strand of PAA sessions focuses on methodological advances rather than substantive findings. In 2024, two areas dominated: Bayesian probabilistic population projections (building on the BayesPop framework developed at the University of Washington) and machine-learning approaches to small-area population estimation in data-sparse regions. The latter is particularly relevant for sub-Saharan Africa and South Asia, where census coverage is incomplete and survey-based estimates carry wide uncertainty bands.
Selected notable sessions
Sub-Saharan Africa fertility transition: pace, heterogeneity, and projection uncertainty
Panel examining whether declining TFRs in Nigeria, Ethiopia, and Tanzania are following earlier-transition country trajectories or diverging. Heavy use of DHS survey data and comparison against the Demographic and Health Surveys Program time series.
The super-ageing threshold: consequences for labour, healthcare, and fiscal sustainability
Cross-national comparison of countries that have crossed the 21% over-65 threshold, drawing on OECD fiscal projections and WHO Global Health Observatory healthcare utilisation data.
Revisions in WPP 2024: what changed and why it matters for long-run projections
UN DESA Population Division staff presented a detailed comparison of WPP 2022 vs 2024 estimates, covering data sources, mortality revisions post-COVID, and updated fertility schedules. The full revision documentation is available at the UN WPP publications page.
Climate migration: current scale, future trajectories, and measurement challenges
Drawing on World Bank Groundswell projections, researchers presented scenarios of internal climate migration affecting 216 million people by 2050. Debate centred on how to incorporate climate displacement into standard demographic projection models.
Why PAA matters for population data users
For anyone working with or interpreting population data, PAA is where the methodological standards get set and contested. When the UN revises its estimates, PAA sessions are where demographers publicly examine those changes. When new data sources emerge — satellite-based population grids, mobile phone data, administrative records — PAA is where the community evaluates their reliability. The papers presented here eventually shape the data behind tools like this one.
The full programme archive and many abstract PDFs from PAA 2024 are available through the PAA 2024 conference page. Papers presented at PAA frequently appear subsequently in Demography, Demographic Research (open access), or Population and Development Review.
Frequently asked questions
What is the Population Association of America?
The PAA is a non-profit scientific organisation founded in 1931 that promotes research on population issues. Its annual meeting is the largest gathering of professional demographers in the world, drawing researchers from universities, government agencies, and international organisations including the UN, World Bank, and WHO.
What were the main themes at PAA 2024?
Key themes included the global fertility decline and its pace in sub-Saharan Africa, rapid ageing in East Asia and Europe, international migration as a demographic stabiliser, first academic reactions to UN WPP 2024, and methodological advances in probabilistic projections and small-area estimation.
Where can I find PAA 2024 papers and presentations?
Abstracts and many full papers are available through the PAA 2024 conference page. Accepted papers are often subsequently published in Demography or Demographic Research (open access).
When and where is the next PAA annual meeting?
PAA 2025 is scheduled for Washington, D.C. The PAA website publishes the call for papers and full programme details ahead of each meeting. Abstract submissions typically open approximately eight months before the conference date.