Mr. Duncan's practice focuses on tax aspects of acquisitions, restructurings and joint ventures; structural planning for global financial services companies, private equity funds and other multinational businesses, advice concerning the implications of domestic and multilateral regulatory and tax developments, including BEPS; derivatives and financial products; complex tax controversies.

Mr. Duncan joined the firm in 1979 and became a partner in 1988. From 1992 to 2008, he was based in the London office.

Mr. Duncan is a member of the Bar in New York and is admitted to practice before the U.S. District Court for the Southern District of New York. He is also a member of the International Fiscal Association

Mr. Duncan received an L.L.M degree from New York University Law School in 1984, a J.D. degree, magna cum laude, from Harvard Law School in 1979 and an undergraduate degree from Yale College.