Mark studies American politics and public policy, especially social welfare policy. He is currently editing a book "The Politics of Sexuality Education" (with Clyde Wilcox) and writing a monograph "Laboratories of Democracy?" He is also writing a series of papers on grading ethics. He has written Fatal Extraction: The Story Behind the Florida Dentist Accused of Infecting His Patients with HIV and Poisoning Public Health (Jossey-Bass, 1997), Public Spirit in the Thrift Tragedy (University of Pittsburgh, 1996), and Welfare Magnets: A New Case for a National Welfare Standard (Brookings Institution, 1990, with Paul E. Peterson), among other book chapters and articles.
His most recent book chapters have appeared in The Politics of Same Sex Marriage (University of Chicago Press, forthcoming) and Promoting the General Welfare (Brookings Institution, forthcoming). His dissertation, The Thrift Tragedy: Are Politicians and Bureaucrats to Blame?, was the co-winner of the 1993 Harold Lasswell Award from the American Political Science Association as the best dissertation in the public policy field.
Mark loves to teach. At the GPPI, he has led courses in Ethics and Values in Public Policy, the Public Policy Process, Quantitative Methods, among others. While at Georgetown, he has been selected as a Teaching Fellow (through CNDLS) and three times has been selected by the students as the outstanding faculty member in the Graduate Public Policy Institute.