He is well known both in the UK and internationally for his research in financial risk management for pension plans and life insurers. In recent years his research has focused on the modelling of longevity risk: how this can be modelled, measured and priced, and how it can be transferred to the financial markets. Amongst his work in this field, he has developed a number of new and innovative stochastic mortality models.
He is an active member of the UK and international actuarial profession: he qualified as a Fellow of the Faculty of Actuaries in 1993; from 1996 to 2017 he was editor of the leading international actuarial journal ASTIN Bulletin - The Journal of the International Actuarial Association and editor-in-chief for the last 10 of these years; and in 2005 he was elected as a corresponding member of the Swiss Association of Actuaries.
His research has received several international prizes including the Halmstad Prize in 2008, the Society of Actuaries Annual Prize in 2009 and the Robert I. Mehr Award in 2016.
In 2016 he was elected as a Fellow of the Royal Society of Edinburgh, Scotland's national academy of science and letters.