Assessment of potential economic consequences in pest risk analysis (PRA) is required if the impact level of an emerging plant disease is ambiguous. Several economic methods are available to conduct a PRA. Three of those are recommended in international agreements: partial budgeting, partial equilibrium and computable
general equilibrium. However, the official authorities responsible for conducting the PRAs, base their economic assessment mostly on expert judgment and rarely on any of these objective methods. The reasons for this discrepancy between practice and theory could be multiple, but one paramount problem is lack of insight in the cost benefit relationship of each method as a tool in PRA. Each method can capture a certain range of impacts but it also has a cost in terms of data, skills and time invested. Optimality is achieved by minimizing the cost, given that the method is able to provide an acceptable level of estimating the impact. From this it follows that there is a trade off between reducing the cost of the method and increasing the accuracy of estimating the pest impact. Therefore, a balance must be found between these two objectives.
This research aims at a better understanding of the cost benefit ratio of available economic methods within the PRA framework and the development ofcriteria that can be used to identify the optimal economic method for a given pest problem.