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.