Hearing Before the Committee on Finance, United States Senate, One Hundred Thirteenth Congress, Second Session, on the Nominations of Darci L. Vetter, to be Chief Agricultural Negotiator, with the Rank of Ambassador, Office of the United States Trade Representative; Stefan M. Selig, to be Under Secretary for International Trade, Department of Commerce; Henry J. Aaron, to be a Member of the Social Security Advisory Board (reappointment); Lanhee J. Chen, to be a Member of the Social Security Advisory Board; and Alan L. Cohen, to be a Member of the Social Security Advisory Board, May 8, 2014