Non-monetary valuation using Multi-Criteria Decision Analysis: Sensitivity of additive aggregation methods to scaling and compensation assumptions

•MCDA supports the non-monetary valuation of ecosystem services.•Additive aggregation methods have important scaling and compensation assumptions.•Results are sensitive to these assumptions. Analytical methods for Multi-Criteria Decision Analysis (MCDA) support the non-monetary valuation of ecosystem services for environmental decision making. Many published case studies transform ecosystem service outcomes into a common metric and aggregate the outcomes to set land use planning and environmental management priorities. Analysts and their stakeholder constituents should be cautioned that results may be sensitive to the methods that are chosen to perform the analysis. In this article, we investigate four common additive aggregation methods: global and local multi-attribute scaling, the analytic hierarchy process, and compromise programming. Using a hypothetical example, we explain scaling and compensation assumptions that distinguish the methods. We perform a case study application of the four methods to re-analyze a data set that was recently published in Ecosystem Services and demonstrate how results are sensitive to the methods.