Social impact measurement as a ‘public value guarantee’ in public–private partnerships? Evidence from a realist evaluation

Public–private partnerships (PPPs) have the potential to address societal challenges and support mission-oriented policies; however, their predominantly economic focus often overlooks the assessment of public value outcomes, which can lead to relational challenges among stakeholders, such as opportunistic behaviour. This article investigates the role of social impact measurement (SIM) in mitigating the relational challenges in PPPs, employing a realist evaluation framework and multiple case studies of Italian PPPs funded by the European Cohesion Policy. The research advances PPP theory and enriches the understanding of SIM by exploring its transactional function, emphasizing its capacity to foster negotiation spaces between stakeholders on social goals and missions. The findings suggest that SIM, when used as a strategic management tool and combined with knowledge transfer among actors, can help address opportunistic behaviour and other relational challenges.