A novel deliberative multicriteria evaluation approach to ecosystem service valuation

Although efforts to address ecosystem services in decision making have advanced considerably in recent years, there remain challenges related to valuation. In particular, conventional economic approaches have been criticized for their inability to capture the collective nature of ecosystem services, for their emphasis on monetary metrics, and the difficulty of assessing the value of ecosystem services to future generations. We present a deliberative multicriteria evaluation (DMCE) method that combines the advantages of multicriteria decision analysis with a deliberation process that allows citizens and scientists to exchange knowledge and evaluate ecosystem services in a social context. Compared with previous applications we add the following: (i) a choice task that can be expected to lead to a more reliable assessment of trade-offs among ecosystem services, and (ii) an explicit consideration of the future by both presenting specific socioeconomic scenarios and asking participating citizens to serve as “trustees” for future generations. We implemented our DMCE framework with 11 panels of residents of the upper Merrimack River watershed in New Hampshire with the goal of assessing the relative value of 10 different ecosystem services in the form of trade-off weights. We found that after group deliberation and expert scientific input, all groups except one were able to reach internal consensus on the relative value of these ecosystem services. Additionally, the pattern of trade-off weights across groups was reasonably similar; there was no statistically significant effect of the specific future scenarios that were presented to the groups. Results of a survey given to participants after the deliberative process revealed that most felt that their opinion during the deliberation was heard by the others and that they were influential on the outcome. Further, the vast majority were satisfied with the outcome of the deliberation. We conclude by discussing the strengths and limitations of our framework at an operational level