Strategic Manipulation of Preference Information in Multi-Criteria Group Decision Methods

When group decisions involve the allocation of resources to group members, the members might have an incentive to strategically distort any information they provide in order to increase their share of resources. The paper compares several multi-criteria group decision methods with respect to this problem. We show, using a computational model, that strategic manipulation of preference information is possible in all of the methods considered, although to a different extent. Furthermore, when the solution a method generates under correct information is not Pareto-optimal, manipulation attempts might even improve the efficiency of outcomes.