"All but one of those just mentioned was a psychologist by education, so it should not be surprising that their view of organization theory emphasizes internal processes and resembles the micro approach of organizational behavior. Another group of theorists, all but one educated as a sociologist, viewed organizations as a product of macro environmental forces. These behavioralists were Jeffrey Pfeffer and Gerald Salancik, Michael Hannan and John Freeman, and John Meyer and Richard Scott. Pfeffer (the only nonsociologist) and Salancik presented a resource-dependent theory that postulates that organizations require support from their external environment and can only survive to the extent that this support is forthcoming. Managers form coalitions to gather support in an open system of external relationships in which there are constraints that create either a munificent or scarce resource situation. Hannan and Freeman’s organizational ecology theory offers the idea that organizational survival is a process of adaptation and success, or fail to adapt and exit. The authors recognized the Darwinian nature of their theory, but have used it to study organizational populations such as labor unions and newspapers for population entries, adaptation, and mortality. The neo-institutional theory of Meyer and Scott (and others) holds that organizational environments are shaped by societal expectations that provide legitimacy to an organization’s existence. By conforming to cultural rules, such as custom or law, formal organizations are able to take on the prevailing view of society."