William Lewis is founding director of the McKinsey Global Institute (MGI) and former partner at McKinsey & Company, where he served for 20 years. He is the author of The Power of Productivity which offers a practical look at the wealth gap between rich and poor countries. Prior to being at McKinsey, he served as acting U.S. secretary of energy, principal deputy assistant secretary of defense, associate provost at Princeton University, and senior financial officer at the World Bank. He has written various articles that have been published in the Wall Street Journal, the New York Times, and the Economist. Lewis is currently chairman of the board of Holy Cross Hospital and a member of the board of the Committee for Economic Development and the George C. Marshall Foundation.