His research studies health care markets, with topics at the intersection of health, industrial organization, and public economics. Much of his work focuses on competition and policy design in health insurance markets, particularly in public programs like the Massachusetts/ACA health insurance exchanges and Medicaid managed care. Mark received his PhD in economics from Harvard University (2015) and his A.B. in applied math from Harvard (2008). He was a Post-doctoral Fellow (in Aging and Health Economics) at the NBER during the 2015-16 academic year before starting as an assistant professor in 2016-17. Before graduate school, Mark spent a year working at the Brookings Institution's Engelberg Center for Health Care Reform (2008-09).