Our beloved and esteemed colleague, Stephen Portnoy, Professor Emeritus in the Department of Statistics at the University of Illinois at Urbana–Champaign, passed away on December 28, 2025. His distinguished career leaves a lasting mark on the University of Illinois and on the field of statistics worldwide.
Steve Portnoy was born in Kankakee, Illinois, in 1942. He completed his undergraduate studies in mathematics at the Massachusetts Institute of Technology in 1966 and earned his Ph.D. in Statistics from Stanford University in 1969. He served as an Assistant Professor in the Department of Statistics at Harvard University until 1974, when he returned to Illinois to join the Department of Mathematics at the University of Illinois at Urbana–Champaign. In 1985, he was a founding member of the newly established Department of Statistics, which he served with dedication until his retirement.
Steve Portnoy was a preeminent statistician who made deep, fundamental, and highly influential contributions in several areas of statistics, including asymptotic theory, robust statistics, and quantile regression. He published more than 100 research articles and supervised over a dozen Ph.D. students. He served as an editor of the Journal of the American Statistical Association (Theory and Methods) and was an elected Fellow of the American Statistical Association, the Institute of Mathematical Statistics, and the American Association for the Advancement of Science.
The statistical community at large, and especially the Department of Statistics at the University of Illinois at Urbana-Champaign, mourn the loss of a great statistician, an exceptional mentor and teacher, and a kind, humble, and generous man.