Stewart is a Senior Advisor at BIT specialising in international development. His work has focused on the application of behavioural insights to public policy with international organisations and foreign governments, including the World Bank, the United Nations Development Programme and the President’s Office in Mexico. Stewart has managed a number of trials for the team including interventions aimed at increasing tax collection in Guatemala and Mexico and improving health outcomes in Moldova, Ukraine and Brazil. Prior to joining BIT, Stewart worked to apply and test the use of behavioural interventions to water and sanitation projects in India. He completed his PhD in Economics at the University of Bristol in 2016.