Spatial models of animal disease control in South America: The case of foot-and-mouth disease

Outbreaks of foot-and-mouth disease (FMD) present significant costs and risks to affected countries, through the disease's rapid spread and its impact on global markets for animal products. To reduce the risk of infection, countries that have eradicated the disease impose strict phytosanitary barriers on imports of animal products. These restrictions create a segmented market in which meat exports from countries that are FMD-free sell at a price premium over products that do not have this designation. FMD has been historically problematic for countries in the Southern Cone (defined as Argentina, Uruguay, Paraguay, and Southern Brazil). After successfully eradicating the disease in the late-1990s and gaining access to FMD-free export markets, FMD re-emerged in the Southern Cone in 2000--2001, resulting in significant economic losses in the region. Certain lucrative markets remain closed as a result.;This research presents three complementary models of FMD control. The first model is a spatially sensitive epidemiological representation of disease spread. The second model is integrated with the first model to determine the short and long run regional and aggregate costs and benefits of alternative mitigation strategies. Results from the integrated epidemiological-economic model indicate that the highest long-term benefits arise from a combined strategy of vaccination in Paraguay and stamping out in the rest of the Southern Cone, though this is sensitive to the size of the outbreak and certain parameter assumptions. While this strategy yields the maximum benefit of those considered, the gains are not distributed equally over the different regions in the Southern Cone. The third model analyzes FMD control behavior in the context of spatial interactions between actors, emphasizing how countervailing incentives based on asymmetries resulting from location and endowments mitigate successful control efforts in the Southern Cone. This model is based on recent literature on social interactions and combines theoretical results using spatial games with cellular automata simulations. The analysis illustrates the difficulties in disease control efforts in the presence of spatial interactions and provides new theoretical insights on spatial games, through the incorporation of heterogeneous incentives and fixed boundaries in the analysis.