Jerald Hage is Professor Emeritus of Sociology at the University of Maryland, College Park, USA. He has written 20 books and a number of important papers. He is a fellow of the American Association for the Advancement of Science and of the American Sociological Research Association. A former president of the Society for the Advancement of Socio-Economics, he has had visiting professorships in a number of countries.Wilbur C. Hadden is Research Scientist at the Center for Innovation, Department of Sociology, University of Maryland at College Park, USA. His research has documented social inequalities and social determinants of health. He has international experience working in Thailand, Pakistan, and China.