Calculating the benefit

Calculating the real benefit of a conservation action by comparing losses and gains isn’t only relevant to the way we do offsets, it applies equally to conservation planning and agri-environment schemes. NERP ED recently reviewed the literature on conservation policy in the three areas of offsets, conservation planning and agri-environment schemes (Maron et al., 2013). They found that the approaches used to calculate conservation benefit often involved assumptions about the alternative scenario that were not explicit, demonstrably wrong or both. Based on this, they believe that assumptions about how conservation value changes over time in the alternative scenario can often be substantially refined, and that making these assumptions explicit by calculating directly the expected difference between the two scenarios is likely to improve the quality of conservation decision-making.

Consider agri-environmental schemes where governments give out money to landholders to do environmental works. The increasing popularity of market-based instruments for the delivery of such funding has led to a proliferation of benefit metrics for comparison of competing bids for funding. These metrics, or utility functions, are derived through a variety of approaches and are intended to represent the benefit being purchased for a given investment in private land conservation, often in order to compare the cost-effectiveness of competing investment options. The researchers examined recent (since 2000) agri-environment schemes that used a quantitative metric of benefit to compare competing bids for funding. They found that rather than calculating conservation benefit as the difference between the ‘with investment’ scenario and the alternative scenario, the difference between the current value and the estimated future value of a site (with investment) was often used. In effect, this reflects a naive assumption that the alternative scenario for a site is one of no change from its current state.

See Decision Point #69 for the complete story

Biodiversity benefit gained at an offset site is the difference between the scenario with the offset action and the baseline scenario (modified from Maron et al. 2013).

Biodiversity benefit gained at an offset site is the difference between the scenario with the offset action and the baseline scenario (modified from Maron et al. 2013).


Maron M, JR Rhodes & P Gibbons (2013). Calculating the benefit of conservation actions. Conservation Letters doi: 10.1111/ conl.12007

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