This paper compares population growth and affluence in developed nations in which per capita income and consumption have been relatively high, and in developing nations in which per capita income and consumption have been relatively low. The paper is one in a series of occasional publications intended to increase understanding of the interrelationships between population growth and socioeconomic and cultural patterns throughout the world, and to communicate this understanding to scholars and policy makers. In this publication, the author uses the consumption of energy and steel between 1950 and 1970 as primary indicators because of the obvious implications of the growth of such parameters upon the environment and the world resource base. Graphs and tables are provided. (Author/RM)