Inertial pressures prevent most organizations from radically changing strategies and structures. - Michael T. Hannan

Hannan and Freeman examine the ecology of organizations by exploring the competition for resources and by trying to account for rates of entry and exit and for the diversity of organizational forms. They show that the destinies of organizations are determined more by impersonal forces than by the intervention of individuals by the intervention of individuals.

Natural selection, as it is actually used in evolutionary population biology, serves mainly as an optimization process. In fact, the reasoning that underlies much evolutionary biology often strikes social scientists as strongly reminiscent of neoclassical economics.

A system with greater organizational diversity has a higher probability of having in hand some form that does a reasonably satisfactory job of dealing with the changed environmental conditions. Adaptation in such a system means reallocating resources from one type of existing organization to another, either by command or by market mechanisms, rather than trying to identify and create appropriate organizational forms.