The new institutionalism in organization theory and sociology comprises a rejection of rational-actor models, and interest in institutions as indepen… - Paul DiMaggio

purportedly represents a distinctive approach to the study of social, economic, and political phenomena; yet it is often easier to gain agreement about what it is not than about what it is.

Both the old and new approaches share a scepticism toward rational-actor models of organisation, and each views institutionalisation as a state-dependent process that makes organisations less instrumentally rational by limiting the options they can pursue. Both emphasise the relationship between organisations and their environments, and both promise to reveal aspects of reality that are inconsistent with organisations’ formal accounts. Each approach stresses the role of culture in shaping organisational reality.

What makes organizations so similar? We contend that the engine of rationalization and bureaucratization has moved from the competitive marketplace to the state and the professions. Once a set of organizations emerges as afield, a paradox arises: rational actors make their organizations increasingly similar as they try to change them. We describe three isomorphic processes—coercive, mimetic, and normative—leading to this outcome. We then specify hypotheses about the impact of resource centralization and dependency, goal ambiguity and technical uncertainty, and professionalization and structuration on isomorphic change. Finally, we suggest implications for theories of organizations and social change.