Critical success factors of Public-Private Partnerships: political and institutional Aspects. Case study of highways in Portugal

Abstract Public-Private Partnerships (PPPs) can be defined as institutional arrangements involving public and private actors in long-term contracts. Considered incomplete contracts, PPPs tend to have increased transaction costs and are associated with the typical problems of principal-agent relationships. In this context, the academy has devoted attention to the study of the critical factors to the performance of PPPs, including political and institutional factors, which is also the focus of this article. Through a qualitative study, based on in-depth interviews and intensive documental analysis, this article aims to study the case of PPPs of highways in Portugal, which have flaws and are currently under great public scrutiny.