ABSTRACT
This chapter argues that the renewed interest in institutions and the emergence of neo-institutionalism within economic theory can mainly be attributed to different fields of applied research. In these fields it has been necessary to look far more closely at institutional relations, as well as at those processes which have resulted in the equilibria that are the central object of study in pure economic theory. Institutions and processes have traditionally held the status of ad hoc models which were intended to supplement the formal equilibrium theory. In recent decades, however, these ad hoc models have developed into independent ‘neo-institutionalist’ theories and research programmes. A typology of the most important of these contributions is set up in order to clarify how the concepts of rationality, institution, and process are modelled in each individual case. In this way we can attempt to clarify the differences between the individual neo-institutionalist contributions, along with their relation to orthodox theory.
