A global meta-analysis on the monetary valuation of dryland ecosystem services: The role of socio-economic, environmental and methodological indicators

Monetary valuation of dryland ecosystem services may help to increase the salience of drylands in decision making. Yet, there is no comprehensive assessment of the indicators that determine the estimated monetary values for dryland ecosystem services (hereafter: dryland value). Having compiled a database consisting of 559 observations from 66 valuation studies in drylands worldwide, this study analyzes the relative importance of local socio-economic, environmental and methodological indicators in explaining the monetary value estimates for nine dryland ecosystem services by means of a multiple regression analysis. By explicitly quantifying the effect sizes of the indicators of dryland value, we shed new light on the driving forces behind monetary valuation of dryland ecosystem services. Our results show that local socio-economic and environmental conditions are marginal in explaining dryland value, indicating that local dryland conditions are not sufficiently captured with current valuation approaches. Simultaneously, we find that methodological factors, including valuation method and study extent, heavily influence dryland value, suggesting that monetary valuation outcomes are largely determined by the selected methodology. This emphasizes the need to improve monetary valuation methods so that they better capture local dryland conditions in order to be able to serve as a meaningful tool for decision making.