International law and litigation, national security, law of war
- Served as the assistant legal adviser for political-military affairs in the U.S. Department of State’s Office of the Legal Adviser
- Embassy legal adviser at the U.S. embassy in Baghdad in 2005, during Iraq’s constitutional negotiations
- Was a 2007-08 Council on Foreign Relations international affairs fellow and a visiting fellow in residence at the Center for Strategic and International Studies
- Since joining the Law School in 2012, has been frequently quoted in the national media on topics such as legal justifications for war, the Edward Snowden affair and the use of cyber and drone warfare. (Faculty Q&A)
Tax policy, legislative process and legal ethics
- Former partner at Caplin & Drysdale in Washington, D.C., practicing federal tax and federal pension law.
- Served twice in the Office of Tax Policy at the U.S. Treasury Department.
- Most recent scholarship (two articles forthcoming in 2017) challenges conventional theory of executive compensation.
Intellectual property, patents, administrative law
- Clerked for U.S. Supreme Court Justice Antonin Scalia and for Judge Stephen Williams of the U.S. Court of Appeals for the D.C. Circuit
- Served as an attorney adviser in the Department of Justice’s Office of Legal Counsel
- In the field of intellectual property, Duffy has been identified as one of the 25 most-influential people in the nation by The American Lawyer and one of the 50 most influential people in the world by the U.K. publication Managing Intellectual Property. He was named a legal “visionary” by the Legal Times in 2009 and has been profiled in Businessweek.