David supports the Open Philanthropy Project with in-depth reviews of evidence on empirical questions, such as: Do alcohol taxes save lives? Does immigration reduce pay or employment for natives? David worked at the Worldwatch Institute for nine years and the Center for Global Development for eleven. After time with the Bill & Melinda Gates Foundation, in 2014 he become an independent consultant, and soon began working with Open Philanthropy on that basis. He became an employee in 2015. David earned a degree in theoretical mathematics from Harvard, and spent an academic year on a Fulbright in Vietnam.