Harnessing informal knowledge leadership in construction projects to boost project performance: the social exchange perspective

Purpose Knowledge-based informal leadership is prevalent in project teams. However, its precise impact on project performance and the mechanisms through which it operates remain unclear. This study aims to conceptualize informal knowledge leadership (IKL) and examine how and when it enhances project knowledge integration and, ultimately, boosts project performance. Design/methodology/approach A quantitative survey was conducted among 636 members of construction project teams in China, including frontline employees from client organizations, construction firms, design firms and consulting firms. Regression analysis was employed to examine the relationships between IKL, knowledge integration and project performance, as well as the moderating roles of perceived organizational support (POS) and psychological contract breach (PCB). Findings IKL significantly promotes knowledge integration, which mediates the positive relationship between IKL and project performance. POS strengthens IKL’s impact on knowledge integration, indicating that supportive environments enhance informal leaders’ effectiveness in facilitating knowledge sharing. However, PCB does not significantly moderate this relationship, suggesting that unfulfilled organizational commitments do not diminish IKL’s positive effects. Originality/value This study advances the understanding of informal leadership in construction projects by identifying the mechanisms through which IKL enhances both knowledge integration and project performance. It also underscores the critical role of organizational support in maximizing the influence of informal leaders. Offering new insights into leadership and knowledge management, this research provides practical guidance for project managers on fostering IKL to improve project outcomes in the construction industry.