Craig R. Humphrey received his Ph.D. from Brown University. He is Associate Professor of Sociology and Demography at Pennsylvania State University, where he teaches courses in environmental sociology, human ecology, and urban sociology. Dr. Humphrey's current research focuses on the application of social theories to study of world population growth, food production, energy, and environmental movements.
The late Frederick H. Buttel was Professor of Sociology and Environmental Studies at the University of Wisconsin-Madison.