Uitdagingen bij het evalueren van de kosten­effectiviteit en meerwaarde van PPS bij publieke infrastructuurprojecten

The core argument to develop public projects and deliver public services through PPPs is that PPPs are cost-effective and would deliver added value over traditional public procurement. Little is known, however, about the extent to which PPPs are indeed cost-effective and deliver added value. This article uses empirical examples to demonstrate and discuss three evaluation strategies to assess the performance of PPPs. The first strategy involves the ex-ante comparison of PPP performance with benchmark data – based on business cases, the public sector comparator, and the public-private comparator – for traditionally public procured projects. The second strategy involves the ex-post comparison of PPP projects with very similar projects that have traditional contracts not including private financing. The third strategy involves the ex-durante comparative evaluation of projects’ operational costs taking a one-year cutout of those operational costs. The three strategies focus, respectively, on the planning and procurement phases, the implementation phase, and the operational phase. Advantages and disadvantages of the strategies are discussed and proposals are offered for combining the strategies and how such combined evaluation strategies can improve decision-making on the use of contract types for the delivery of public projects and services.