Johan P. Olsen (b. 14 August 1939 in Tromsø, Norway) is professor in political science and Director of Research at the Centre for European Studies, University of Oslo. Either alone or in collaboration with colleagues, he has written or edited 19 books and written more than 100 book chapters and articles, many of them in leading international journals. Together with James G. March and Michael D. Cohen he developed the 'garbage can'-model of organizational decision making, and together with March he launched the concept of 'new institutionalism' in the mid 1980s. He received the American Political Science Association's John Gaus Award for his life-long contribution to public administration and political science