Associate Professor of Statistics
Tutorial Fellow at Worcester College
I moved to Oxford from Queen’s University in Kingston, Ontario, where I was associate professor in the Department of Mathematics and Statistics. Before then I was a postdoc at UC Berkeley for six and a half years, in the departments of demography and statistics, following in stints at the Technical University of Delft and the Technical University of Berlin. I completed my PhD in probability theory in the Harvard University Department of Mathematics in 1996, working with Persi Diaconis.
- Stochastic processes
- Random dynamical systems
- Survival analysis
- Human sex ratio
- Markov chain Monte Carlo
I am currently interested primarily in biological and demographic questions connected with ageing and mortality. I have been working on improving the probability-theory machinery that underlies some theoretical analyses of the evolution of ageing, and developing statistical methods that help to bring together experiments with these theories. This has largely been in the area of survival analysis, but I have also increasingly been concerned with Bayesian methods for analysing longitudinal data. My demographic interests have branched out to include the human sex ratio and genetic determinants of human life history traits.
I continue to work on fundamental questions of stochastic processes, in particular the behaviour of stochastic flows, the asymptotics of killed Markov processes, and the growth rates of populations dynamics in random environments.
- With K. Wachter and A. Dahl, Statistical properties of simple random-effects models for genetic heritability, bioRxiv 087304.
- With S. Tuljapurkar, Stochastic growth rates for life histories with rare migration or diapause, (2016), arXiv:1505.00116.
- With S.H. Orzack et al., The human sex ratio from conception to birth, (2015), PNAS, 112 (16), E2102-E2111.
- With Martin Kolb, Necessary and sufficient conditions for convergence to quasistationary distributions for one-dimensional diffusions with killing, Ann. Probab. Vol. 40, No. 1, (2012), pp. 162-212.
- With Steven N. Evans and Kenneth W. Wachter, A mutation-selection model for general genotypes with recombination.
- With Shripad Tuljapurkar and Carol Horvitz, Derivatives of the Stochastic Growth Rate, Theoretical Population Biology, 80:1 (2011), pp. 1-15.