Frank W. Young first became interested in the social causation of health in the context of development studies, where the central question was and still is "Why are some communities better off than others?" "Better off" was understood to mean income and wealth, but around 1970 the range of criteria was enlarged to include the "physical quality of life," especially life expectancy and infant mortality. The new criteria opened the door to broader sociological research on development and to the study of what we now call "population health." This book explores the issues that impact public health.