Straightening the three streams: Theorising extensions of the multiple streams framework

Abstract This article suggests theoretical refinements to the multiple streams framework (MSF) that make it applicable to parliamentary systems and the decision‐making stage of the policy process. Regarding the former, the important role of political parties in parliamentary democracies is highlighted. Party policy experts are expected to be members of the policy communities in the policy stream and to promote viable policy alternatives in their respective parties, while the party leadership is concerned with adopting policies in the political stream. With regard to the latter, the introduction of a second coupling process to analyse decision making more rigorously is suggested. Moreover, the article provides operational definitions of the framework's key concepts when applied to parliamentary systems and derives a systematic set of falsifiable hypotheses for agenda‐setting and decision making in these systems, thus addressing one of the main critiques against the MSF – namely that no hypotheses can be derived from it.