The 2025 winner of the Pierre Robillard Award of the Statistical Society of Canada is Liyuan Lin. Liyuan’s thesis, entitled "Measures for risk, dependence and diversification", was written while she was a doctoral student at the University of Waterloo working under the supervision of Ruodu Wang and Alexander Shied.

Liyuan’s main research area is quantitative risk management. Under a unifying theme of dependence and risk problems, the thesis contains nine different papers, including seven that were either published or accepted when the thesis was nominated for the award. They vary from topics on the quantitative theory of finance and actuarial science to more foundational ones in probability and statistics motivated by understanding different concepts of dependence. Notably, she introduces a new diversification index called the diversification quotient (DQ) to address the fundamental question of “How diversified is an investment portfolio?” The DQ is based on six economic axioms, and it can be applied to different risk measures. It addresses several theoretical and practical limitations of existing indices. The special cases of DQ built from industry-standard risk measures offer a strong link to advances in the modern risk management literature. This new diversification index has the potential to have a large impact on the field.

Several other papers are devoted to various aspects of dependence including joint mixability and notions of negative dependence, pairwise counter-monotonicity, negatively dependent optimal risk sharing, invariant correlation under marginal transforms, optimal transport theory, and the checkerboard copula. With publications in management science, actuarial science, operations research, mathematical finance, and statistics, Liyuan’s thesis shows an incredible breadth with strong theory and potential for applications in finance, actuarial science, as well as other scientific areas where statistics and dependence play a major role.

Liyuan is a Senior Lecturer in the Business School at Monash University, Australia. She obtained a Bachelor (2017) and a Master (2020) degree in Economics from the Central University of Finance and Economics (CUFE) in China. She completed her PhD in Actuarial Science at the University of Waterloo. She is an Associate of the Society of Actuaries.