Strategic experts’ weight manipulation in 2-rank consensus reaching in group decision making

Abstract

In group decision-making (GDM) problems, decision makers may prefer to divide the alternatives into two preference-ordered categories, which is called a 2-rank GDM problem. In the process of 2-rank GDM, consensus is of great significance for the aggregation of individual opinions, in which the experts’ weight plays a key role in the consensus level among experts, and different expert weights may lead to different 2-rank consensus results. Thus, a coordinator may strategically set experts’ weight to attain the desired consensus level, which we call strategic experts’ weight manipulation in 2-rank consensus reaching in GDM. In this study, first, we provided the concept of 2-rank consensus level range, and then we constructed a few mixed 0–1 linear programming models to compute the strategic experts’ weights to obtain the coordinator’s desired 2-rank consensus level, and the property is provided. Finally, we conducted a numerical example and a few simulation experiments to validate the effectiveness of our proposed models, and to show the effect of the number of experts and alternatives, respectively, on the process of strategic experts’ weight manipulation in 2-rank consensus reaching in GDM.