Integrating similarity analysis and ecosystem service value transfer: Results from a tropical coastal wetland in India

Policy demand for ecosystem service values in developing countries results in a growing use of value transfer techniques, even in the absence of primary valuations from highly comparable study sites. Current techniques provide limited guidance on how to quantitatively assess the similarity between study and policy sites and control for the effect thereof on transfer accuracy. This paper proposes a methodology for the estimation of a study-policy site similarity index and explores its application to the Akkulam-Veli wetland in Kerala, India. The use of empirical similarity weights in a meta-analytical transfer yields a narrower prediction interval for the policy site value estimate. Estimating the meta-regression model parameters on a subset of primary valuation studies with greater similarity to the policy site application is found to increase value transfer accuracy. The need for further systematic testing and potential implications of the proposed approach for value transfer practitioners are highlighted.