Multiple-Multiple Streams: Rethinking the Multiple Streams Framework for Polycentric Governance

This paper advances the Multiple Streams Framework (MSF) by developing a polycentric Multiple-Multiple Streams Framework (MMSF) for analyzing policy processes characterized by horizontal coordination among autonomous actors. While existing MSF research has successfully extended the framework to multi-level and federal settings, it largely retains a monozentric logic in which agenda-setting and stream coupling occur within a single institutional arena. This limits its analytical leverage in governance settings where multiple formally independent decision centers operate on the same level and must coordinate without hierarchical steering. Building on Ostrom’s concept of polycentric governance and the organizational logic of the Garbage Can Model, the paper conceptualizes decision centers as collectively structured actors with internally shared problem perceptions, policy orientations, and expectations about appropriate action. Each center generates its own problem, policy, and politics streams, reflecting group-specific interpretive frames and strategic priorities. Policy change emerges not through a single policy window, but through intra- and inter-center coupling processes that enable coordination, negotiation, and collaboration across centers. The framework specifies different types of decision centers and identifies coupling mechanisms through which policy entrepreneurs broker and translate group-specific problem framings and policy ideas, thereby facilitating collaborative alignment across autonomous actors. These mechanisms capture how cooperation can emerge despite divergent preferences, resource asymmetries, and parallel agenda-setting processes. The MMSF is empirically examined through a qualitative theory-testing case study of intermunicipal cycling infrastructure planning in Germany, a prototypical case of polycentric and collaborative governance. The findings demonstrate how group-specific orientations shape problem definitions and policy proposals, how coordination challenges arise from misaligned stream constellations, and how coupling processes enable or constrain collaborative outcomes. By integrating polycentric governance and group-based dynamics into the MSF, the paper contributes to policy process theory and offers a process-oriented explanation of collaboration in complex, multi-actor policymaking environments.