Land Use, Climate Change and the Emergence of Infectious Diseases: A Synthesis

Scientific evidence suggests that anthropogenic impacts on the environment, such as land use changes and climate change, promote the emergence of infectious diseases in humans. We provide a synthesis which captures interactions between the economy and the natural world and links climate, land use and infectious diseases. We develop a two-region integrated epidemic-economic model which unifies short-run disease containment policies with long-run policies which could control the drivers and the severity of infectious diseases. We structure our paper by linking susceptible-infected-susceptible and susceptible-infected-recovered models with an economic model which includes land use choices for agriculture, climate change and accumulation of knowledge that supports land augmenting technical change. The infectious disease contact number depends on short-run policies (e.g., lockdowns, vaccination), and long-run policies affecting land use, the natural world and climate change. Climate change and land use change have an additional cost in terms of infectious diseases since they might increase the contact number in the long run. We derive optimal short-run containment controls for a Nash equilibrium between regions, and long-run controls for climate policy, land use and knowledge at an open loop Nash equilibrium and the social optimum. Short- and long-run controls are then unified. We explore the impact of ambiguity aversion and model misspecification in the unified model. Numerical simulations support the theoretical model and provide quantitative indications of the importance of infectious diseases in policy design.