About the Author: Constance E. Helfat is the J. Brian Quinn Professor in Technology and Strategy at the Tuck School of Business at Dartmouth. Professor Helfat focuses her research on firm capabilities and knowledge, involving technological innovation and adaptation and change of firm capabilities over time. Sydney Finkelstein is the Steven Roth Professor of Management at the Tuck School of Business at Dartmouth. Will Mitchell is the J. Rex Fuqua Professor of International Management and Professor of Strategy at Duke University's Fuqua School of Business. Margaret A. Peteraf is Professor of Strategic Management and Organization at the Tuck School of Business at Dartmouth. Harbir Singh is the William and Phyllis Mack Professor at the Wharton School, and the Co-Director of the Mack Center for Technological Innovation. David J. Teece is the Mitsubishi Bank Professor and Director of the Institute of Management, Innovation and Organization, Haas School of Business, University of California, Berkeley. Sidney G. Winter is the Deloitte and Touche Professor of Management at The Wharton School of the University of Pennsylvania.