Odd Aalen

Odd Olai Aalen (born 1947) is a Norwegian statistician renowned for his contributions to survival analysis, stochastic processes, and causal inference. He is particularly known for his work on the Aalen additive hazard model and the development of counting process theory in survival analysis.

Aalen received his doctorate in mathematical statistics from the University of California, Berkeley in 1975. He has held professorships at the University of Oslo and currently holds a position at the Norwegian Institute of Public Health.

His research has focused on developing statistical methods for analyzing time-to-event data, often encountered in medical research, demography, and reliability engineering. The Aalen additive hazard model, a non-parametric regression model for survival data, allows for time-varying effects of covariates, providing a flexible alternative to the more common Cox proportional hazards model. His work has also been instrumental in establishing a rigorous mathematical foundation for survival analysis through the use of counting processes and martingale theory.

Aalen's work has had a significant impact on the field of biostatistics and has been widely applied in various areas of scientific research. He is a fellow of the Institute of Mathematical Statistics and has received numerous awards for his contributions to statistics. Beyond his technical contributions, Aalen has also contributed to the philosophy of causality in statistics, offering insights into the nature of causal inference and its limitations.