From atoms to allies: a social network analysis of information and resource exchange in hubs for circularity

Hubs for Circularity (H4C) represent collaborative networks, where multiple stakeholders work together to implement circular industrial practices, such as waste reduction, resource sharing, and material reuse, supporting the EU’s sustainability goals outlined in the Green Deal and Circular Economy Action Plan. Despite the acknowledged importance of communication and knowledge sharing in industrial symbiosis (IS), the specific social structures underlying these networks within H4C remain underexplored. This study applies Social Network Analysis (SNA) to examine stakeholder communication patterns and resource flows within four distinct H4C sites from the European IS2H4C project, located in the Basque Country, the Netherlands, Germany, and Türkiye. Data was collected through the workshop and desk research, for both communication (undirected, unweighted) and resource (directed, unweighted) networks. Our analysis suggests that H4C networks may represent a variation of traditional IS arrangements, with some characteristics that could enhance generalizability to other collaborative sustainability initiatives. The findings highlight varied stakeholder roles: industrial entities typically occupy central positions, research institutions function as knowledge brokers, community actors, while generally peripheral, can assume leadership roles through effective local engagement mechanisms, and regulatory bodies predominantly maintain peripheral positions. We find that stakeholder diversity and governance structures play key roles in network effectiveness, with implications for how circular economy (CE) collaborations might be designed.