Environmental scientists employ political and economic arguments to argue for the conservation of biodiversity and the maintenance of ecosystem services. However, the economic terminology has a number of connotations which makes its usefulness for the intended effect questionable.
On the one hand, the basic assumptions underlying economic valuation are far from realistic and represent rather a caricature of human behaviour. On the other hand, the methods based on these assumptions are manifold and lead to wildly diverging results. Thus the calculated value of ecosystems and their services is not a robust figure, but varies with the valuation method applied (plus a plethora of subjective assumptions). As a result, it is not possible to ‘objectively’ calculate the value of ecosystem services. Fortunately, it is also not necessary to do so. Given the inherent flaws of the valuation process, it seems more promising for biodiversity and its conservation to restrict the economic calculus to the role of a contribution in the implementation process for a set of politically defined targets, rather than using it as the target setting mechanism itself.
The paper lists some of the core assumptions, presents a systematic overview of the most relevant valuation methods, illustrates them by providing examples and discusses their limitations. As an alternative, political target setting is suggested, based on a multi-stakeholder, multi-criteria analysis. Market prices play a role in this analysis, as one factor amongst others. For the implementation, cost-effectiveness analysis gives important hints, and economic instruments – inter alia – can play an important role as enforcement mechanisms. However, incentives should be based on criteria of (potential) effectiveness, not on value calculations.
