His research specializes in public economics, with a focus on issues of taxation and inequality. He has studied the use of taxes both for redistribution and as an instrument to change behavior. Recent work explores the use of work subsidies such as the Earned Income Tax Credit to accomplish redistribution while encouraging work, and the growing use of soda and sweetened beverage taxes to improve health outcomes. He has also studied the use of income taxes to encourage talented individuals to pursue professions beneficial to society.