Marion is Professor of Health Economics at CHERE. Formerly a physiotherapist, she has a Masters of Public Health (University of Sydney), a Graduate Diploma of Applied Epidemiology (NSW Health) and a PhD (University of Sydney). A leading health services researcher for many years, Marion has extensive policy and research based experience of health services funding and financing in Australia.

Her research interests are in the application of economic analysis to policy and practice; planning and evaluating health services; incorporating health economics into health services research, including clinical trials; the application of discrete choice methods to consumer preferences in health; and understanding the impact of health policy on access to, utilisation and costs of health care services.

She is currently a chief investigator on a number of major NHMRC grants, including a CRE in Women's Sexual and Reproductive Health (SPHERE). Between 2010 and 2017, Marion was one of the leaders of the Cancer Research Economics Research Team (CREST) at CHERE. She is an honorary life member of the Health Services Research Association of Australia and New Zealand.