In my judgment this book in honor of Donald T. Campbell will be very influential and highly cited. . . . It will become a must read for Ph.D. students and scholars in strategy and organization theory. —Arie Lewin, Duke University "The topics in this volume are cutting edge, and the contributors are first-rate. The book is well anchored—Donald T. Campbell has had a profound influence on the field. Moreover, the book is well-conceptualized—socio-cultural evolution, co-evolution, methods modeling, and epistemology are key issues in organization science right now. —Michael Tushman, Harvard University If he were an assistant professor today, what would social science giant Donald T. Campbell be pursuing in the field of organization science? Joel A. C. Baum and Bill McKelvey explore this question in Variations in Organization Science. This volume reveals and celebrates Campbell′s many contributions to organization science by presenting new variations that stem directly from his work. Rather than analyze Campbell′s theories, the authors present ideas that Campbell might have pursued if he were currently a doctoral student. This volume is unique in its focus on coevolution and multilevel coevolutionary analysis, as well as in its range of subject matter from empirical studies to leading-edge epistemological discourses. Each of the book′s four main sections focuses on a major aspect of Campbell′s legacy: blind variation, selection, and retention; multilevel coevolution; process level analysis and modeling; and epistemology and methodology. In addition, the volume includes a Foreward by Barbara Frankel Campbell and an unusual Appendix: Donald Campbell′s complete curriculum vitae. Variations in Organization Science should be on the top of the reading list for any organization scientist interested in organizational evolution, change, and competitiveness. This volume will also appeal to any scholar interested in the human and social capital base of firms and how organizational knowledge and learning work to provide the basis of competitive advantage.