Exotic and invasive species and bioterrorism are of increasing concern for U.S. policy makers. The economic analysis of these issues, especially bioterrorism, is a fast-growing, relatively new area. It is an area where an economist can provide important input into both policy and applied theory. The two papers in this section address invasive species issues.
In the exotic species literature, one often sees control strategies divided into five levels. The first level of control is prevention, which includes those activities designed to prevent the introduction of exotic species into an ecosystem. The next level is detection and monitoring; this includes finding those species that get past the prevention measures, then discovering the range they inhabit, their population density, and how these are changing over time. Detection of an invasive species then triggers either eradication, the elimination of the species, control, which is generally taken to mean making the population density and/or area affected as small as possible; or, if control fails, adaptation. Eradication is the preferred option for dealing with exotic species outbreaks when feasible and cost effective.
Both of these papers focus on the trade-offs between monitoring and eradication costs, looking at a specific exotic species in a specific U.S. state. Elbakidze and McCarl look at Foot and Mouth Disease (FMD) in Texas; Pierre, Spreen, and Moss examine the effects of the Mediterranean fruit fly in Florida. Both sets of researchers use a stochastic, dynamic programming approach in modeling the species. They also benefit in focusing on specific species because we know what kind of technology works to eradicate these species. (We also know that these species can be eradicated; they have been successfully eradicated from the United States and other countries.) Both papers are motivated by the insight that monitoring and other preoutbreak investments can reduce the costs of eliminating an exotic species if an outbreak occurs. Monitoring by itself may allow us to catch exotics sooner, before they have a chance to spread over a wide area. Also, as Elbakidze and McCarl point out, preoutbreak investments in eradication or control can increase the effectiveness and reduce the costs of efforts in dealing with invasive outbreaks.
FMD and Mediterranean fruit flies are both controlled partly by quarantines of the infected areas. Mediterranean fruit flies are to some degree self-propelled, but can spread more rapidly in infected produce. FMD can travel in infected animals and their meat and be carried by humans, other animals, or equipment that comes in contact with infected animals. The largest part of the costs of dealing with an outbreak of either species is the disruption in trade. FMD is particularly serious because an outbreak anywhere in the United States would effectively eliminate U.S. exports of red meats for several months. The infected parts of Texas would be quarantined from the rest of the United States as well. A Mediterranean fruit fly outbreak could prevent shipments of Florida produce out of the state. Neither of these studies accounts for the costs of lost markets, which is not, in my opinion, a serious flaw. Neither claims to be a complete analysis of their pest. Both focus on the trade-off between monitoring and eradication costs. The tradedisrupting effects of these species are the reasons why we will eradicate any outbreaks. I would assign the costs of lost markets to the failures of the prevention programs. A complete analysis of either species would include linking the monitoring and eradication costs with the prevention costs.
FMD in Texas
I start with Elbakidze and McCarl. Their discussion of the pre- and postoutbreak costs and decision making is excellent. I also like the fact that they start with a simple, theoretical model showing the optimal trade-offs between pre- and postoutbreak activities. Their basic model is a type of dynamic, stochastic programming model with two levels of decisions. …