The leadership hierarchies of 3 Mississippi communities with single major population centers of around 20,000 in 1970 were compared in terms of 3 dimensions--complexity, coordination, and openness. Similar in population size and organizational complexity, the communities were all county seats and centers for multicounty programs. They differed in: agricultural resources and history, the extent of nonagricultural employment growth since WW II, and the proportion of the population which was Negro. Data were collected from 236 persons. Complexity was measured by the extent or volume of the individual's participation in programs and organizations. Measures of coordination were the degree of generalization, represented by the number of institutional interest areas in which a leader participated and the number and proportion of leaders involved in the major voluntary coordinating organization, and the awareness and opinions that the leaders had of each other. Measures of openness dealt with the characteristics and mobility of leaders. The leadership groups were compared by age, schooling, occupation, and race. Some findings were: in each community and in each type of participation, there was a high correlation between coordination and complexity of participation; and openness did not show as much difference between the communities. (NQ)