Abstract The Panel Evaluation Method was developed to deal with complex and controversial resource allocation proposals. It links and extends the capabilities of Environmental Impact Assessment and Cost-Benefit Analysis, accomplishing a comprehensive and systematic evaluation of competing proposals. The paper focuses on the Significance Measurement Technique, which was designed to determine the relative significance of impacts so that proposals could be ranked according to the efficiency criterion. It is shown to produce replicable measurements of efficiency, thus providing a satisfactory means of assessing the benefits and costs of a proposal. This paper also reports on an investigation undertaken to further test the reliability of PEM.