Existing demographic analyses do not explain the negative relationship between population growth and life-support systems that are now emerging in scores of developing countries. The demographic transition, a theory first outlined by demographer Frank Notestein in 1945, classified all societies into one of three stages. Drawing heavily on the…

Aside from the growth of world population itself, urbanization is the dominant demographic trend of the late twentieth century. The number of people living in cities increased from six hundred million in 1950 to over two billion in 1986. If this growth continues unabated, more than half of humanity will reside in urban areas shortly after the turn…