William Arthur Niskanen (March 13, 1933 – October 26, 2011) was an American economist noted as one of the architects of President Ronald Reagan's economic programme and for his contributions to public choice theory.
Between 1985 and 2008, Niskanen was the chairman of the Cato Institute, following service as a member and acting chairman of President Reagan's Council of Economic Advisers. Niskanen also served as director of economics at the Ford Motor Company, professor of economics at the University of California at Berkeley and Los Angeles, assistant director of the federal Office of Management and Budget, a defense analyst at the Rand Corporation, the director of special studies in the Office of the Secretary of Defense, and the director of the Program Analysis division at the Institute of Defense Analysis. He wrote on many public policy issues including corporate governance, defense, federal budget policy, regulation, Social Security, taxes, and trade. Niskanen's 1971 book Bureaucracy and Representative Government is considered a classic. His final book was Reflections of a Political Economist: Selected Articles on Government Policies and Political Processes.