economics Practical Magic

If you want to know when the next big animal disease outbreak is coming, look at the price of meat, not the weather or biology.

March 25, 2026

Original Paper

Seasonal Impacts on Brucellosis Transmission Mediated by Live Sheep Supply-Demand Dynamics

Qi Wang, Liu Yang, Meng Fan

SSRN · 6458316

The Takeaway

This study shows that market demand creates a 'competition' between government disease culling and private profit. When market prices for sheep are high, farmers are incentivized to hide sick animals to sell them rather than report them, making stricter detection policies counter-productive during peak demand seasons.

From the abstract

To explore how market supply-demand dynamics mediate seasonal brucellosis transmission, a non-autonomous periodic model with market feedback is developed, addressing the oversight of market-driven dynamics in existing models by integrating seasonal fluctuations of core market factors with epidemiological processes. Theoretically, coincidence degree and evolution operator theories confirm the existence and globally asymptotic stability of periodic solutions in the market-disease framework, achiev