Evolutionary Mechanism of Trust for Public–Private Partnership Projects with Public Participation

Trust plays a pivotal role in sustaining cooperative relationships and serves as the cornerstone of successful cooperation among participants in public–private partnership (PPP) projects. A decline in trust can result in unethical behavior, fractured relationships, and even project failure. Despite its critical importance, there is an insufficiency of research exploring the evolutionary dynamics of trust, particularly from the perspective of public participation. To address this, an evolutionary game model is constructed to analyze the evolution of behavioral strategies and identify their stable state from a dynamic perspective. The model examines the influence of trust levels and public participation on cooperation, revealing that trust asymmetry negatively impacts collaborative outcomes in PPP projects. There is an optimal trust level: trust positively influences cooperation up to a certain peak, beyond which excessive trust becomes detrimental and hinders cooperative outcomes. When trust levels are equal, the selection of behavioral strategies is influenced by the initial willingness of participants. A threshold exists for this initial willingness, above which cooperation is more likely to succeed. Additionally, public participation is found to significantly enhance cooperation. These conclusions advance the theoretical advancements of trust in PPP projects and offer valuable insights for policymakers and stakeholders in addressing trust-related challenges, thereby fostering sustainable collaboration.