I am an economist by training with advanced degrees in development economics and environmental health impact evaluation. I specialise in policy research on topics like water, sanitation and hygiene, governance and agriculture using methods like impact evaluation, systematic review and meta-analysis. I set up the Systematic Reviews Programme and London Office of the International Initiative for Impact Evaluation (3ie), based at London International Development Centre. I was elected Co-Chair of the Campbell Collaboration International Development Coordinating Group (2014-19), and continue as an editor with Campbell Systematic Reviews. I was seconded to 3ie's Impact Evaluation Office as Senior Evaluation Specialist in New Delhi (2014-16). Previously, I was employed for two years in the Ministry of Finance and Economic Planning (MINECOFIN) of the Government of Rwanda (2006-2008). I have also been employed at the World Bank's Operations Evaluation Department (now Independent Evaluation Group) in Washington D.C., the UK National Audit Office, and the Poverty Research Unit at Sussex University. I have consulted or conducted assignments for the Department for International Development, the Economist Intelligence Unit, the International Finance Corporation, Save the Children UK, and Sightsavers. My education includes BSc Economics from the University of York, MA Development Economics from the University of Sussex and PhD Infectious Disease and Public Health Impact Evaluation from LSHTM.