The impact of population size, physical density, social density, and age of600communities upon the extent of their industrial diversification was analyzed. Hypotheses concerning each independent variable were generated from the theory of the development of the division of labor proposed by Durkheim and subsequently adopted by human ecologists. Regression analysis was employed to test the hypotheses.The standardized partial regression coefficients indicated that only social density exerts a significant impact upon industrial diversification. In addition, it was discovered that the combined influence of the independent variables fails to account for the bulk of the variation in industrial diversification. Factors which may be responsible for these results, as well as directions for future research, are presented and discussed.