Changbao Wu is a Professor of Statistics in the Department of Statistics and Actuarial Science at the University of Waterloo. He obtained his PhD in Statistics from Simon Fraser University in August 1999 and joined Waterloo as an Assistant Professor in September 1999. He became an Associate Professor in 2005 and a Full Professor in 2011. 

Changbao’s doctoral dissertation was titled “The Effective Use of Complete Auxiliary Information from Survey Data” and was written under the supervision of the late Professor Randy Sitter. It was Professor Sitter who taught him that a good researcher should possess abilities in both “problem formulation” and “problem solving”, a lesson Randy learned from his own PhD supervisor, Professor Jeff C.F. Wu. For his dissertation research, Changbao proposed the concept of “model-calibration”, initially as a generalization of conventional calibration methods to handle nonlinear working models. In a series of papers published from 2001 to 2003 in the Journal of the American Statistical Association, Biometrika, and Statistica Sinica, he showed that model-calibration techniques provide an optimal strategy for the efficient estimation of general parameters and revealed the intrinsic connection between linear working models and the conventional calibration methods. His subsequent work with collaborators and students further demonstrated a wide range of applications of model-calibration in missing data analysis and causal inference. 

Empirical likelihood methods for complex survey data are another major topic of Changbao’s research. In collaboration with Professor Jon Rao of Carleton University and Professor Puying Zhao of Yunnan University, Changbao addressed several fundamental problems in survey data analysis, along with computational implementation of the proposed methods. These include pseudo empirical likelihood ratio confidence intervals and regions for general finite population and/or analytic model parameters, estimation with dual- and multiple-frame surveys, Bayesian empirical likelihood methods, inferential tools for analyzing public-use survey data files, and strategies for estimating parameters of interest in economic studies such as inequality measures. Major results from this work were published in the Journal of the American Statistical Association, the Journal of the Royal Statistical Society (Series B), and the Journal of Econometrics. 

One of Changbao’s recent research topics is the analysis of non-probability survey samples. Together with doctoral student Yilin Chen and her co-supervisor Professor Pengfei Li, they proposed a pseudo maximum likelihood method for estimating participation probabilities and a general framework for combining information from multiple sources to achieve valid and efficient inference. The research was published in 2020 in the Journal of the American Statistical Association and has been widely cited in the recent literature. Changbao’s 2022 single-author discussion paper in Survey Methodology, with five prominent researchers as discussants, has become a regular reference on the topic.  

Changbao was a member of methodology teams for several large-scale real-world surveys, including the International Tobacco Control (ITC) Policy Evaluation Project and the Canadian Longitudinal Study on Aging (CLSA). He has provided advice and consultation to agencies and organizations on statistical methodology, serving as a member of Statistics Canada’s Advisory Committee on Statistical Methods since 2015, and as an advisor to survey projects conducted by Canadian Institute for Health Information (CIHI) and the First Nations Information Governance Centre (FNIGC). Some of the practical issues, along with methodological advances arising from these projects, became part of his book (co-authored with Professor Mary Thompson), Sampling Theory and Practice, published by Springer in 2020. The book has become a popular reference among survey researchers and practitioners and has accumulated more than 116,000 online accesses/downloads on Springer Nature Link as of March 2026. 

Changbao has provided important service and leadership to the Canadian statistical sciences community. He served as President of the Survey Methods Section of SSC in 2005, Program Chair of the 2014 SSC Annual Meeting in Toronto, and SSC Meetings Coordinator (2015 – 2020). He was a member of the NSERC Liaison Committee for Mathematics and Statistics (2016 – 2019) and President of the ICSA – Canada Chapter (2015 – 2017). As a co-team leader with Professor David Haziza (formerly University of Montreal and currently University of Ottawa), they have successfully led three CANSSI Collaborative Research Teams (CRT) over the past ten years. At the University of Waterloo, Changbao has served as Chair of the Department of Statistics and Actuarial Science since 2022.  In addition, he has served as an Associate Editor for several statistical journals, including The Canadian Journal of Statistics, Survey Methodology, Biometrika, and the Journal of the American Statistical Association (Theory and Methods). 

Changbao was born in 1963 and grew up in a small Wu village in Anhui Province, China. None of his parents or earlier generations had the opportunity for formal schooling. Although the family endured hardships before the1980s, as many Chinese families did, Changbao was fortunate to be among the first group of students at the village elementary school, which opened in 1969 with a single teacher who himself had not finished high school. Changbao was the first person not only in his family but also in several nearby villages to gain admission to university in 1978, when the national college entrance examinations were reinstated after the Culture Revolution. He graduated in 1982 from Anhui Laodong University (later disintegrated into three other universities) with a bachelor’s degree in mathematics and the highest GPA in his class, and became a full-time faculty member at Hefei Normal University at the age of nineteen. He pursued graduate studies in statistics (MS Diploma) at East China Normal University (1985-1986) and remained a faculty member at Hefei Normal University until 1995. His desire to pursue high-level research, along with the only full financial support package he received from Simon Fraser University, led to his remarkable academic journey in Canada. 

Changbao is extremely grateful to his professors at Simon Fraser University, his colleagues at the University of Waterloo, his collaborators in North America and beyond, and all the students and postdoctoral research fellows who helped shape his academic journey over the past 30 years. 

Changbao and his wife Jane raised their two daughters, Domeny and Miranda, in Waterloo. They are extremely proud of what the two daughters have accomplished, both in their career pursuits and as remarkable individuals. Domeny and her husband Bryan now work and live in Los Angeles; Miranda is completing her second master’s degree in the Faculty of Medicine at the University of Toronto. The family enjoys every opportunity to get together, either in person or through chat groups.