Viviana Ventre

Consensus in Multiperson Decision Making Using Fuzzy Coalitions

We consider the problem of group decisions, in which decision-makers have different opinions or interests. This study proposes various metric spaces for representing the movements of decision-makers for reaching consensus. We also introduce the concept of fuzzy coalition for developing an algorithm for building a feasible fuzzy coalition, which is defined as the union of winning maximum coalitions which solve the issue of consensus among decision-makers.

Analyzing AHP Matrix by Robust Regression

The Analytic Hierarchy Process (AHP) is a powerful process to help people to express priorities and make the best decision when both qualitative and quantitative aspects of a decision need to be considered. In this paper, in order to eliminate the influence of outliers, we use an approach based on Robust Partial Least Squares (R-PLS) regression for the computation of the values for the weights of a comparison matrix. A simulation study to compare the results with other methods for computing the weights proposed to analyze comparison matrix.

On Consistency and Incoherence in Analytical Hierarchy Process and Intertemporal Choices Models

A rational choice is based on conditions of coherence, that are universally accepted rules to which a decision-maker must comply in expressing his/her preferences. In this paper, we focus on two different approaches in decision-making processes, i.e. the Analytical Hierarchy Process and Intertemporal Choices models, highlighting the consistency conditions usually adopted. After a general discussion on consistence and incoherence in the framework of these two different approaches, we show that sometimes it is preferable to weaken or reinforce coherence conditions according to the specific context.

Modelling the Intertemporal Choice through the Dynamic Time-Perception

The process of intertemporal choice is intimately linked with the concept of discounting function. Usually the benchmark in this important financial tool is the instant 0. This is an actual constraint for economic agent decision-making; indeed, in many situations, individuals have to decide at instants different from 0. Obviously, this introduces a multicriteria decision making framework in which a group of agents can (or cannot) cooperate in order to obtain greater profitabilities in function of the time variable. In this financial context, it is necessary to choose between transitive and non-transitive choice, giving rise to additive and non-additive (which includes subadditive and superadditive) discounting, respectively. Finally, another classification distinguishes between discounting with increasing or decreasing impatience.

Decision Making in Social Actions

Decision making in a social ambit involves both individual optimal choices and social choices. The theory of “perverse effects” by Boudon shows that the sum of rational individual choices can produce a very undesirable global effect. Then decision making in social action must keep into account the theory of cooperative games with many players, in order to obtain the optimal strategies. Because of the semantic uncertainty in the definition of social actions, it is preferable assume that the issues are represented by fuzzy numbers.