Speaker:    Professor Adrian Raftery, University of Washington, Seattle

Title:           Bayesian Probabilistic Subnational Population Projections

Abstract:  Population projections have until recently usually been done deterministically using the cohort-component method, yielding a single value for each projected future population quantity of interest. Starting in 2015, the United Nations Population Division changed their approach, instead adopted a fully statistical Bayesian probabilistic approach to project fertility, mortality and population for all countries, using methods developed by our group. In 2024, for the first time, uncertainty about net international migration was also included. 

In this approach, the total fertility rate, female and male life expectancies at birth, and the net migration rate are projected using Bayesian hierarchical models estimated via Markov chain Monte Carlo. These are then combined with a cohort-component model, yielding probabilistic projections for any future quantity of interest. The methodology is implemented in the bayesPop R package, which has been used by the UN to produce the World Population Prospects since 2015. We have recently extended the method to subnational population projections. I will describe the method and some recent extensions, and illustrate it with subnational demographic data from several countries. 

Bio: Adrian E. Raftery is Blumstein-Jordan Professor Emeritus of Statistics and Sociology at the at the University of Washington in Seattle. He was born in Dublin, Ireland, and obtained a B.A. in Mathematics (1976) and an M.Sc. in Statistics and Operations Research (1977) at Trinity College Dublin. He obtained a doctorate in mathematical statistics in 1980 from the Université Pierre et Marie Curie in Paris, France under the supervision of Paul Deheuvels. He was a lecturer in statistics at Trinity College Dublin from 1980 to 1986, and then an associate (1986-1990) and full (1990-2024) professor of statistics and sociology at the University of Washington. He was the founding Director of the Center for Statistics and Social Sciences (1999-2009).

Raftery has published over 240 articles in peer-reviewed statistical, sociological and other journals. His research focuses on Bayesian model selection and Bayesian model averaging, model-based clustering, inference for deterministic simulation models, and the development of new statistical methods for demography, sociology, and the environmental and health sciences.

He is a member of the United States National Academy of Sciences, a Fellow of the American Academy of Arts and Sciences, an Honorary Member of the Royal Irish Academy, a member of the Washington State Academy of Sciences, a Fellow of the American Statistical Association, a Fellow of the Institute of Mathematical Statistics, and an elected Member of the Sociological Research Association. He has won the Population Association of America's Clifford C. Clogg Award, the American Sociological Association's Paul F. Lazarsfeld Award for Distinguished Contribution to Knowledge, the Jerome Sacks Award for Outstanding Cross-Disciplinary Research from the National Institute of Statistical Sciences, the Parzen Prize for Statistical Innovation, and the Science Foundation Ireland St. Patrick's Day Medal. He is also a former Coordinating and Applications Editor of the Journal of the American Statistical Association and a former Editor of Sociological Methodology. He was identified as the world's most cited researcher in mathematics for the decade 1995-2005 by Thomson-ISI.

He is currently an associate editor, and Chair of the Statistical and Methodological Review Committee for PNAS, and a deputy editor of the journal Demography. Thirty-four students have obtained Ph.D.'s working under Raftery's supervision, of whom 21 hold or have held tenure-track university faculty positions. He has 165 academic descendants.