This book argues that rationality and market equilibrium assumptions are inconsistent with rigorous strategic management research so that strategic management should adopt behavioral assumptions. When strategy scholars assume that firms can make better or worse decisions, they implicitly adopt a behavioral view. After examining the problems that rationality and equilibrium assumptions create, the author outlines the basics of a behavioral approach to strategic management. The book addresses how a behavioral approach relates to several major strains of strategic management scholarship and explores relevant methodological issues. Overall, the book argues persuasively that a behavioral perspective offers the best foundation for strategic management scholarship.