Explicit and Implicit Weighting Schemes in Multi‐criteria Decision Support Systems: The Case of the National Innovative Housing Quality Program in Italy

While institutionalized and purely contractual public-private partnerships (PPPs) are supposed to be helpful to carry out urban regeneration interventions, many of such projects - especially in Italy - are developed under the framework of negotiation-based PPPs, also known as negotiating partnerships. The structuring process of negotiation-based PPPs extensively uses various valuation approaches and methods, with a remarkable role played by multi-criteria decision support systems. The literature focuses on using valuation approaches and methods in this field, pointing out the potentialities that can be exploited and the limitations that should be addressed. This paper places itself within this debate and tries to address an inherent issue in multi-criteria decision aid (MCDA) techniques. Here we show that there could be a gap between the explicit weighting system used in MCDA analysis and the implicit weighting system actually employed. The issue is discussed using the National Innovative Housing Quality program, lastly adopted in Italy, as a testbed. As a case study, we consider the program proposal defined by the municipality of Treviso, North-eastern Italy. Implicit weights are identified ex-post according to the allocation of funding to the intervention projects. While confirming a difference in comparison to the importance of the criteria identified a priori by the public body that governs the program, we also argue that the gap narrows if assuming that the project options match the criteria according to a nonlinear relationship. The originality and value of this paper lie in addressing a topic that is underestimated in the reference literature. Instead, its thorough consideration might help structure program proposals based on negotiating partnerships that are more effective.