A novel framework to operationalise value-pluralism in environmental valuation: Environmental value functions

The environmental valuation literature has, to date, been governed by the single ontology/epistemology of neoclassical environmental economics and monetary valuation, which has led to a mis- or un-representation of other ways of understanding and conceptualising environmental value. Consequently, calls have been made to better represent plural values in environmental valuation studies. Additionally, the environmental valuation literature has been characterised by a prevalent focus on the assessment of total or absolute value of ecosystems. Yet, there appears to be a consensus that the examination of marginal or relative changes in value would in fact be more informative. In this study, we address these gaps in environmental valuation by presenting Environmental Value Functions (EVF), a new valuation framework that accounts for value-pluralism and develops value analysis at the margin. Our framework is based on the estimation and application of value functions, each of which describe the relationship between the value and quantity (or quality) of an ecosystem component of interest. In EVF, values are estimated in terms of change relative to the current level, instead of calculating absolute values. Recognising that some environmental values likely cannot be conceptualised in terms of marginal changes, we introduce the concept of binary/categorical value and thereby develop EVF to also account for non-marginal value conceptualisations. In sum, EVF simultaneously enables 1) the recognition of value-pluralism; 2) the integration of multiple valuation methods (monetary and non-monetary); 3) marginal and non-marginal value analysis. The coupling of EVF and ecosystem modelling can offer novel insights to the study of temporal environmental value dynamics, including the prediction and analysis of volatility, long-term trends, and temporal trade-offs.