"Criticisms of Mancur Olson's theory of group membership and organizational behavior and discussions of the limits of his formulations are not new, but Terry Moe has set them forth in thoroughgoing fashion, has elaborated and extended them, and has made positive new contributions. The result is a book that is valuable and constructive, one that may well revive interest in the systematic study of political groups."--David B. Truman, American Political...