The benefits and costs of specific phytosanitary campaigns in the UK: examples that illustrate how science and economics support policy decision making

Three examples of benefit/cost analyses (BCA) conducted in recent years in the UK to support phytosanitary policy are summarized. Following the first UK outbreak of Thrips palmi, the costs incurred during the eradication campaign were compared with potential-losses forecast by modelling the spread and impact of T. Palmi in glasshouse crops over ten years. The resultant BCA justified the strict statutory action taken to achieve eradication. The second example, the eradication of a plant pathogen, Ralstonia solanacearum, from a river system showed that the expense of a statutory campaign is justified only if eradication can be achieved within a few years. A more protracted campaign would lead to costs outweighing benefits. A third analysis examining the economic impact of implementing EU control measures on Diabrotica virgifera virgifera, an insect pest of maize that is currently spreading across Europe, highlights the importance of assessing the cost of implementing measures as well as the benefits of avoiding losses caused by the target pest. This last example shows that strict implementation of control measures can be more costly than the damage likely to be caused by the pest. The strengths and weaknesses of benefit/cost studies, and their future use in relation to plant health issues are discussed. I am grateful to Prof. Lansink and the Frontis organization for inviting me to participate in the workshop. Benefit/cost analyses were funded by Defra Plant Health Divisio