The role of epistemic and normative similarity in inter-organizational online relations: a self-categorization perspective on the bioplastics field

Sustainability transitions unfold through the interactions of heterogeneous actors, yet the discursive mechanisms that structure inter-organizational affiliation remain poorly understood. This study examines whether organizations' publicly articulated epistemic and normative positioning is associated with the formation of interorganizational ties and the emergence of coherent relational communities in the bioplastics field. Drawing on self-categorization theory, we advance a multilevel perspective in which organizations are treated as socially recognizable collective actors whose public positions provide categorical cues for affiliation, community formation, and differentiation. Conceptualizing epistemic and normative similarity as two dimensions of symbolic proximity, this perspective extends proximity-based accounts of inter-organizational relations by linking dyadic similarity to the emergence of internally coherent and comparatively differentiated communities. We reconstruct a hyperlink network of 4161 organizations across all world macro-regions, connected by 28,151 hyperlink ties, and derive their epistemic and normative positioning from web content using a transformer-based topic model and an automated UN SDG classifier. Dyadic logistic regression shows that epistemic and normative similarity positively predict tie formation, net of geographical, institutional, and social proximity, with a significant positive interaction between the two dimensions. At the community level, OLS regression and permutation tests show that greater relational density is associated both with higher internal epistemic and normative coherence within communities and with stronger differentiation from other communities in the field. These findings suggest that the relational architecture of sustainability transitions is partly constituted by the symbolic positioning organizations publicly display, shaping how coordination, fragmentation, and transition governance unfold across heterogeneous organizational fields.