Weighted multi-criteria decision-making with coalition strategies: a framework for citizens public participation

Abstract Public planning decisions affect the living conditions of diverse categories of people differently. Therefore, voters should express their support and/or rejection to each alternative. Since their opinions tend to be subjective, intensities of support and rejection should be collected and processed (rather than binary yes , no voting) to reveal whether an agreement is in favour or against each alternative. However, inconsistent responses (simultaneous high levels of support and rejection) for the same alternative represent a challenge. The next challenge is the different influence of alternatives to diverse citizens subgroups. To address these issues, this work proposes strengthening the consistent answers and weakening the contradictory responses by the convex combination of t-norm and t-conorm function. Next, the impact of coalitions (agreement) among subgroups is formalised by fuzzy measures and Choquet integral, because the impact is different when two of the most affected subgroups or two lightly affected subgroups agree on a specific alternative. In real-life problems through the Traffic Strategy Case Study in the Street of Unterdorf in Geuensee, Lucerne (Switzerland), 13 alternatives were evaluated by four subgroups of voters. Fuzzy measures or weights are assigned to each subgroup and their possible coalitions considering their features. In addition, the sensitivity analysis is performed by Monte Carlo simulation. Finally, topics for future work are outlined.