Investing to Both Prevent and Prepare for COVID-XX.

One cause of the high rate of COVID-19 cases in the USA is thought to be insufficient prior capital investment in national health programs to preemptively reduce the likelihood of an outbreak and in national capacity to reduce the severity of any outbreak that does occur. We analyze the choice of capital investments (e.g. testing capacity, stockpiles of PPE, and information sharing capacity) and find the economically efficient capital stock associated with mitigating pandemic risk should be dramatically expanded. Policymakers who fail to invest in public health forgo significant expected cost savings from being prepared.

Chronic wasting disease undermines efforts to control the spread of brucellosis in the Greater Yellowstone Ecosystem.

Wildlife diseases pose a substantial threat to the provisioning of ecosystem services. We use a novel modeling approach to study the potential loss of these services through the imminent introduction of chronic wasting disease (CWD) to elk populations in the Greater Yellowstone Ecosystem (GYE). A specific concern is that concentrating elk at feedgrounds may exacerbate the spread of CWD, whereas eliminating feedgrounds may increase the number of elk on private ranchlands and the transmission of a second disease, brucellosis, from elk to cattle. To evaluate the consequences of management strategies given the threat of two concurrent wildlife diseases, we develop a spatiotemporal bioeconomic model. GPS data from elk and landscape attributes are used to predict migratory behavior and population densities with and without supplementary feeding. We use a 4,800 km2 area around Pinedale, Wyoming containing four existing feedgrounds as a case study. For this area, we simulate welfare estimates under a variety of management strategies. Our results indicate that continuing to feed elk could result in substantial welfare losses for the case-study region. Therefore, to maximize the present value of economic net benefits generated by the local elk population upon CWD's arrival in the region, wildlife managers may wish to consider discontinuing elk feedgrounds while simultaneously developing new methods to mitigate the financial impact to ranchers of possible brucellosis transmission to livestock. More generally, our methods can be used to weigh the costs and benefits of human-wildlife interactions in the presence of multiple disease risks.

Economic Incentives for Managing Filterable Biological Pollution Risks from Trade.

Infectious livestock disease problems are "biological pollution" problems. Prior work on biological pollution problems generally examines the efficient allocation of prevention and control efforts, but does not identify the specific externalities underpinning the design of efficiency-enhancing policy instruments. Prior analyses also focus on problems where those being damaged do not contribute to externalities. We examine a problem where the initial biological introduction harms the importer and then others are harmed by spread from this importer. Here, the externality is the spread of infection beyond the initial importer. This externality is influenced by the importer's private risk management choices, which provide impure public goods that reduce disease spillovers to others-making disease spread a "filterable externality." We derive efficient policy incentives to internalize filterable disease externalities given uncertainties about introduction and spread. We find efficiency requires incentivizing an importer's trade choices along with self-protection and abatement efforts, in contrast to prior work that targets trade alone. Perhaps surprisingly, we find these incentives increase with importers' private risk management incentives and with their ability to directly protect others. In cases where importers can spread infection to each other, we find filterable externalities may lead to multiple Nash equilibria.

The Economic Case for a Pandemic Fund.

The rapid urban spread of Ebola virus in West Africa in 2014 and consequent breakdown of control measures led to a significant economic impact as well as the burden on public health and wellbeing. The US government appropriated $5.4 Billion for FY2015 and WHO proposed a $100 Million emergency fund largely to curtail the threat of future outbreaks. Using epidemiological analyses and economic modeling, we propose that the best use of these and similar funds would be to serve as global insurance against the continued threat of emerging infectious diseases. An effective strategy would involve the initial investment in strengthening mobile and adaptable capacity to deal with the threat and reality of disease emergence, coupled with repeated investment to maintain what is effectively a 'national guard' for pandemic prevention and response. This investment would create a capital stock that could also provide access to safe treatment during and between crises in developing countries, lowering risk to developed countries.

Managing Disease Risks from Trade: Strategic Behavior with Many Choices and Price Effects.

An individual's infectious disease risks, and hence the individual's incentives for risk mitigation, may be influenced by others' risk management choices. If so, then there will be strategic interactions among individuals, whereby each makes his or her own risk management decisions based, at least in part, on the expected decisions of others. Prior work has shown that multiple equilibria could arise in this setting, with one equilibrium being a coordination failure in which individuals make too few investments in protection. However, these results are largely based on simplified models involving a single management choice and fixed prices that may influence risk management incentives. Relaxing these assumptions, we find strategic interactions influence, and are influenced by, choices involving multiple management options and market price effects. In particular, we find these features can reduce or eliminate concerns about multiple equilibria and coordination failure. This has important policy implications relative to simpler models.

Managing Wildlife Faced with Pathogen Risks Involving Multi-Stable Outcomes.

Most models designed to understand how to manage infected wildlife systems with bioeconomic multi-stability take the initial conditions as given, thereby treating pathogen invasion as unanticipated. We examine how ex ante management is an opportunity to influence the ex post conditions, which in turn affect the ex post optimal outcome. To capture these ex ante management choices, we extend the Poisson "collapse" model of Reed and Heras (Bull Math Biol 54:185-207, 1992) to allow for endogenous initial conditions and ex post multi-stability. We account for two uncertain processes: the introduction and establishment of the pathogen. Introduction is conditional on anthropogenic investments in prevention, and both random processes are conditional on how we manage the native population to provide natural prevention of invasion and natural insurance against establishment placing the system in an undesirable basin of attraction. We find that both multi-stability of the invaded system and these uncertainty processes can create economic non-convexities that yield multiple candidate solutions to the ex ante optimization problem. Additionally, we illustrate how the nature of natural protection against introduction and establishment risks can play an important role in the allocation of anthropogenic investments.

Managing dynamic epidemiological risks through trade.

There is growing concern that trade, by connecting geographically isolated regions, unintentionally facilitates the spread of invasive pathogens and pests - forms of biological pollution that pose significant risks to ecosystem and human health. We use a bioeconomic framework to examine whether trade always increases private risks, focusing specifically on pathogen risks from live animal trade. When the pathogens have already established and traders bear some private risk, we find two results that run counter to the conventional wisdom on trade. First, uncertainty about the disease status of individual animals held in inventory may increase the incentives to trade relative to the disease-free case. Second, trade may facilitate reduced long-run disease prevalence among buyers. These results arise because disease risks are endogenous due to dynamic feedback processes involving valuable inventories, and markets facilitate the management of private risks that producers face with or without trade.

Managing the Endogenous Risk of Disease Outbreaks with Non-Constant Background Risk.

There is a growing concern that risks of disease outbreak and pandemics are increasing over time. We consider optimal investments in prevention before an outbreak using an endogenous risk approach within an optimal control setting. Using the threat of pandemic influenza as an illustrative example, we demonstrate that prevention expenditures are relatively small in comparison to the potential losses facing the USA, and these expenditures need to be flexible and responsive to changes in background risk. Failure to adjust these expenditures to changes in background risk poses a significant threat to social welfare into the future.

Merging economics and epidemiology to improve the prediction and management of infectious disease.

Mathematical epidemiology, one of the oldest and richest areas in mathematical biology, has significantly enhanced our understanding of how pathogens emerge, evolve, and spread. Classical epidemiological models, the standard for predicting and managing the spread of infectious disease, assume that contacts between susceptible and infectious individuals depend on their relative frequency in the population. The behavioral factors that underpin contact rates are not generally addressed. There is, however, an emerging a class of models that addresses the feedbacks between infectious disease dynamics and the behavioral decisions driving host contact. Referred to as "economic epidemiology" or "epidemiological economics," the approach explores the determinants of decisions about the number and type of contacts made by individuals, using insights and methods from economics. We show how the approach has the potential both to improve predictions of the course of infectious disease, and to support development of novel approaches to infectious disease management.