Essays on the bioeconomic analysis of wildlife and livestock disease problems

The spread of infectious disease among both wild and domesticated animals has become a major problem worldwide. It not only becomes a global threat to human health, but also poses great economic losses to the society. Many infectious diseases are often unobservable without investments to discover disease status, and prior bioeconomic work focuses on imperfect controls in the sense that these investments have not been made---generally because they are technologically not possible. Policies are also generally based on this situation. This dissertation focuses on analyzing two separate disease problems, Brucellosis and Bovine Tuberculosis (bTB), in order to better understand when it is worthwhile to invest in observability of disease status and how this can be used to improve management.;This dissertation is divided into two essays. The first essay applies an econometric model of US cattle trade to forecast bTB transmission across cattle herds in the US. I first develop a gravity model of livestock trade and then link it to an epidemiological model of bTB transmission, with the goal being that this information could lead to improved disease surveillance and management. The findings suggest that targeting surveillance efforts towards high disease risks states could be more effective than targeting efforts only towards states known to be infected or targeting efforts equally across all states.;The second essay is about brucellosis management in bison in Yellowstone National Park. It investigates the combination of vaccination and test-and-slaughter by applying an optimal control approach whereby the disease dynamics can be affected by both management actions and changes in human-environmental interactions. The results suggest that investments in observability (testing) are inferior because the manner in which vaccination performs is superior---it not only prevents infections, but also helps contribute to the resistant population, in turn increase the overall healthy population. Yet, the differences are relatively small, and there might be transaction costs associated with implementing the oscillated controls. Therefore, the decision of choosing vaccination or test-and-slaughter would depend on whether the transaction costs of running the program actually offset differences of social net benefits.