AnalysisImproving inspections of agricultural products

Published 7 September 2009

Agricultural goods crossing into the United States are subject to Agricultural Quarantine Inspection (AQI) by DHS’s Customs and Border Protection (CBP); current practices call for inspecting 2 percent of the items in a container; a new study says that applying decision-making theory to inspections would improve them and make them more effective

At U.S. ports of entry, the contents of air, maritime, truck, and rail cargo, as well as air passenger baggage, vehicles, and mail are subject to Agricultural Quarantine Inspection (AQI) by DHS’s Customs and Border Protection (CBP) officials. The purpose of AQI is to help ensure that U.S. agriculture is protected from accidentally or intentionally introduced pests and diseases, including the possibility of agroterrorism. In general, current practice for inspecting cargo shipments of fruits and vegetables at U.S. ports is based on inspecting 2 percent of the items in a container for the presence of pests, with some allowances for the size, contents, and origin of the container.

In a recent study, Joe Moffitt, John Stranlund, and Craig Osteen write that although simple to apply, this inspection rule appears not to have any economic content; that is, it does not consider the costs of inspections or the losses of failing to prevent an invasive species from entering the country. Nor does it account for the severe uncertainty associated with infestations in shipping containers and the potential losses from introductions of poorly understood or surreptitiously introduced invasive species. In their paper the three scholars propose an alternative decision criterion for determining inspection probabilities that incorporates economic considerations with particular emphasis on the severe uncertainties of pest introductions and damage.

Bringing risk analysis to imports inspection
They write that with probability distributions over invasive species introductions and their impacts, one could cast the problem of determining optimal inspection rules in the familiar terms of risk analysis. In would then be relatively straightforward to specify inspections rules that balanced the costs of inspections against the expected benefits of preventing introductions of pests. Doing this, however, would require information that policy makers do not possess, cannot obtain at all, or cannot obtain within a timeframe that is useful. “In many areas of economic decision making, including the management of invasive species, it is often difficult to measure and interpret probability distributions associated with uncertain outcomes. Consequently, concerns about the usefulness of risk assessment in the management of invasive species are evident among researchers and practitioners alike,” they write.

Several approaches have been developed to analyze decision making in uncertain environments, including application of the maximin, maximax, Laplace, and Hurwicz criteria (see the original paper for the references). The first two of these approaches represent polar extremes in terms of optimism and pessimism while the latter two require information similar to probabilities to be applied.