Multiple leadership, as a stable system of goal determination and policy setting, is most likely to be found in organizations where there are multiple goals and where these goals lack precise criteria of achievement and allow considerable tolerances with regard to achievement. Organizations with a single goal [i.e., proprietary hospitals] or a clear hierarchy of goals provide little basis for multiple leadership. Multiple leadership arises because important group interests diverge, and each group has the power to protect its interests.

Charles Perrow (1963). "Goals and Power Structures: A Historical Case Study." In: E. Friedson, (Ed.), The Hospital in Modern Society. New York: The Free Press, p. 132