The (in)validity of benefit transfer and its consequences for policy-making

Abstract

The essence of benefit transfer is that the assessment of ecological effects of an intended project is based on information from similar studies, undertaken at other sites. Instead of performing a completely new study, which may cost a lot of time and money, key parameters from older studies are used. This approach is assumed to save valuable research time and money. In the paper it will be shown that this benefit may occur at the expense of the validity of assessments. Using these assessments for the new project may result in sub-optimal decision-making by governments and other stakeholders, like private landowners. The paper contains a meta-analysis on the validity of benefit transfer. The two basic types of benefit transfer, simple benefit transfer and benefit function transfer are being compared. It turns out that the validity of simple benefit transfer is often poor even when applied at comparable sites. This raises the question whether simple benefit transfer should be used to support policy-making regarding investment scenarios of national importance. It may be better to use benefit function transfer as an alternative, because it can compensate for differences in explanatory variables. In this way, the validity of the assessment can be increased, which may lead to 'better' decisions, provided that suitable benefit functions are available.