Invasive species are one of the main reasons for the loss of biodiversity. According to the Convention on Biological Diversity (CBD) national strategies have to be developed to deal with biological invasions. Economic evaluation studies of biological invasions and of measures against them can be used to support the decision process as a tool of policy advice. In this paper, we analyse whether the economic studies available so far are suitable for that task.

This will be done in a two-step procedure. In a more general analysis, 23 studies are surveyed and critically analysed in order to assess the field of application they could be used in. Out of these studies, ten are analysed in detail to assess their methodological quality, e.g., whether they consider all relevant types of values.

As general findings we note: (1) current studies mostly have methodological shortcomings compared to their theoretical basis; (2) they concentrate on ex-post assessment and neglect ex-ante considerations; (3) prevention, the strategy favoured by the CBD, has been hardly reflected; and (3) the high degree of uncertainty associated with biological invasions is insufficiently addressed. With regard to these findings we state that the results of current studies should be carefully used. For the development of a national strategy they are less suitable.