Consistency of the results of different MCA methods: a critical review

Multiple criteria decision analysis (MCA) has become an indispensable tool for dealing with complex and unstructured decision problems in environmental and natural resource management which involve a number of conflicting objectives and a variety of stakeholders. Despite their popularity, choosing which of the many multicriteria methods to use is tricky. Different methods may yield different results and therefore the decision may depend on the method selected. In this paper we review a number of experiments conducted to compare the results of different MCA methods when applied to the same decision problem. I compare and critically examine the hypotheses postulated and the results obtained from these experiments. Despite the equivocal results yielded in some experiments, many authors recommend applying two or more MCA methods, especially in the case of unstructured decision problems. This multimethod MCA application may be regarded as a type of validation which is more extensive than standard sensitivity analysis and which enables the decisionmaker to review the preferences and judgments previously elicited by a single method.