Digital platforms have become a central part of the modern digital economy. While private platforms dominate much of the scholarly discourse, public platforms are gaining traction. Yet, research on public platforms remains fragmented and provides limited insight into how core platform mechanisms operate within institutional constraints. Often, private platform concepts are transferred to the public sector without systematic adaptation, leading to untapped potential or the failure of public platforms . This study addresses this research gap by examining what defines public platforms and how they differ from private ones. Drawing on 13 case studies across education and public administration in Germany, 32 qualitative interviews, and a comparative analysis, we develop a theoretical framework that identifies core mechanisms of public platforms across constitutional, functional, relational, behavioral, structural, and contextual dimensions. These mechanisms include, e.g., multi-sided user connections, value creation, incentive systems, pricing strategies, governance structures, and market dynamics. Despite structural similarities, our findings reveal that public platforms function fundamentally differently from private platforms. They follow a distinct platform logic under institutional conditions that reconfigure their core mechanisms. By mapping and comparing these mechanisms within a coherent framework, the study advances conceptual clarity in public platform research and offers theoretical guidance on why the potential of public platforms is often not fully realized. • Multiple case study of education and administration platforms in Germany. • Develops a theoretical framework for analyzing public platforms in federal systems. • Identification of core traits distinguishing public and private digital platforms. • Differences: value creation, ownership, governance, incentives, and competition. • Similarities: user group structures, role constellations, and interaction patterns.
Rauch et al. (Thu,) studied this question.