Conflict Analysis on the Enforced-Move-by-Majority Rule in a Group Decisionmaking Situation

Group decisions inherently contain conflicts of interests among participants. Many group decision support systems have been introduced in order to effectively and efficiently induce final decisions after group discussions. Among many group decision support systems, we focus on the Yonmenkaigi System Method (YSM) which was originally developed for the group decision situations especially for participatory community planning discussions. The debate phase of YSM where each group of debaters can decide strategies/options that belong to their individual roles, has an unique rule that an option of one group can be forced to change by other majority participants in debate. This rule is modeled by utilizing Conflict Analysis model and the effects of the rule in equilibrium are clarified. It is shown that the rule can bring about improvement in players´ overall payoffs. It is also shown that the rule can sometimes improve equality of payoffs among players especially when the result of group discussion tends to stick to the situation favorable to only one participant and not to majority.