Multi-level relationship patterns among private-sector organizations in public–private partnerships: a network perspective with evidence from China’s transportation sectors

Purpose The nature of public-private partnership (PPP) markets, industry competition, and organizational embeddedness (e.g. collaboration experience), significantly influence how private-sector organizations in PPP establish relational ties and create project networks during the PPP procurement phase. This necessitates a multi-level perspective to unveil the relationship mechanisms and behaviors of organizations in PPP at different levels. This study aims to analyze the industry, clustering, and local characteristics of organization relationships using a longitudinal dataset of PPP transportation projects sourced from the National PPP Integrated Information Platform (NPPPIIP). Design/methodology/approach This study adopts a multi-level analytical approach, encompassing whole-network, clustering-network, and local-network levels, to explore the mechanisms of organizational relationships and behavioral patterns within collaboration networks among private-sector organizations. Findings The results indicate that (1) organizational relationships within PPP unfold spontaneously over time, driven intrinsically and collectively, devoid of prior planning, control, external direction, or imposed order at the industry level, with the evolution of four collaboration types elucidating the emergence of self-organizing networks; (2) super enterprises exhibit exceptional breadth, brokerage, and ego abilities, and relationship patterns are governed by the effects of geographic proximity and preferential attachment at the clustering level; and (3) local relationship patterns are characterized by embeddedness mechanisms, including relational and structural aspects. Originality/value The multi-level analysis framework enhances our understanding of organization interactions in the PPP procurement phase, breaking away from the traditional social network analysis (SNA) at both the network-centric and ego-centric levels. Overall, the insights are valuable for policymakers designing improved tendering processes and for PPP private-sector organizations seeking a comprehensive overview of competition and collaboration in the transportation infrastructure sector.