I am Director of the Centre for the Analysis of Taxation (CenTax) and a Professor of Economics at the University of Warwick. I am also a Research Fellow at the Institute for Fiscal Studies, and have affiliations with the International Inequalities Institute, the CAGE Research Centre, CESifo, and the IZA. I am an Editor at International Tax and Public Finance where I manage the Policy Watch section, Associate Editor at Fiscal Studies, and on the Editorial Board of the Economics Observatory.

I study issues of migration, tax compliance, tax design, and inequality with a focus on those with high incomes or wealth. I am a Commissioner at the Wealth Tax Commission. I also work on issues of environmental taxation, economic development, migration, and tax in low- and middle-income countries.

I am co-chair of the Discover Economics campaign, aiming to increase the diversity of people who study and work in economics. From 2020-22 (creation to abolition) I was a member of the Department for Education Skills and Productivity Board.