Who is a Stream? Epistemic Communities, Instrument Constituencies and Advocacy Coalitions in Multiple Streams Subsystems

John Kingdon’s Multiple Streams Framework (MSF) was articulated in order to better understand how issues entered into policy agendas, using the concept of a policy actors interacting in course of sequences of events occurring in what he referred to as the "problem", "policy" and "politics" "streams". In this study Kingdon used an undifferentiated concept of a ‘policy subsystem’ to organize the activities of various policy actors involved in this process. However, it is not a priori certain who the agents are in this process and how they interact. This paper argues the policy world can also be visualized as being composed of different distinct subsets of subsystem actors who engage over specific sets of interactions over the definition of policy problems, the articulation of solutions and their matching or enactment. Using this lens, this article focuses on actor interactions involved in policy formulation activities occurring immediately following the agenda setting stage upon which Kingdon originally worked. This activity involves the definition of policy goals (both broad and specific) and the creation of the means and mechanisms to realise these goals. The article argues this stage is best analyzed form the perspective of three separate sets of actors involved in these tasks: the epistemic community which finds itself engaged in discourses about policy problems; the activities of instrument constituencies which define the policy stream in which policy alternatives and instruments are formulated; and that of advocacy coalitions which make up the politics stream as they compete to have their choice of policy alternatives selected by decision makers. The article argues these different sets of policy actors personify each of Kingdon’s three different streams of policy, problem and politics and that extending Kingdon’s work to the examination of policy formulation using this basic vocabulary yields superior insights into policy formulation than other extant models.