Stanley L. Engerman is Professor Emeritus at the University of Rochester, New York and a Research Associate at the National Bureau of Economic Research, Massachusetts. Among his books are Time on the Cross: The Economics of American Negro Slavery (with Robert William Fogel, 1974), Slavery, Emancipation, and Freedom: Comparative Perspectives (2007), and Economic Development in the Americas since 1500: Endowments and Institutions (with Kenneth L. Sokoloff, Cambridge, 2011).