Paul's research is in health economics and aims to inform how limited resources committed to health care can be allocated in ways most likely to lead to improvements in population health and wellbeing.

Paul is a Professor at the Centre for Health Economics (CHE), University of York, where he leads research programmes in global health evaluation. His research is policy-orientated and aims to inform the international community and national-level policy-makers on issues of resource allocation and health. He is also involved in initiatives to support training and capacity strengthening in health economics at African public universities.

Paul has affiliated positions with the MRC Clinical Trials Unit, at University College London, and the Centre for Global Development in Washington DC, as well as with the Overseas Development Institute. In addition to research activities, he supports the ODI Fellowship scheme through country visits and training of fellows posted to ministries of health.