Global livestock trade and infectious diseases

Abstract

Large-scale movement of animals through trade can spread diseases to places where they are not endemic. In this paper, we identify the causal effect of global livestock trade on the spread of infectious animal diseases through an exogenous increase in the demand for imported livestock. The instrumental variable approach exploits an increase in halal livestock imports in Muslim countries during Eid-al-Adha to determine the effect of livestock imports on related infections. Using a dataset that covers 123 countries and five livestock categories in the months between 2004 and 2019, we find an imports-to-infections elasticity of about 0.75. The relationship is stronger for countries that are likely to import infected livestock from their partners. There is also evidence that infections spread through interaction between imported livestock, some of which might be infected, and domestic livestock. These results highlight transmission-through-trade from the origin to the destination.