Delaying the Inevitable? U.S. Screwworm Closures and Feeder Cattle Market Dynamics

Biosecurity trade restrictions are commonly framed as preventive measures, yet in many settings they function primarily as policies of delay: they impose immediate market costs while only postponing the arrival of biological risks. This paper evaluates that intertemporal tradeoff using the 2024–2025 US suspension of live cattle imports from Mexico in response to the northward spread of New World Screwworm (NWS). We estimate a vector autoregression (VAR) using monthly data from 2004 to 2025 to characterize pre‐ban dynamics in feeder cattle prices, Mexican import volumes, fed cattle prices, and feed costs, and construct counterfactual forecasts for prices and trade flows absent the border closures. Translating these costs into a simple break‐even framework shows that under an annual endemic‐loss assumption of $10 billion, each additional month of border closure would need to delay endemic NWS establishment by approximately 4 months to be welfare improving.