Economic profitability versus ecological entropy

There is a long-standing trade-off in bioculture between concentrating on h igh-yield varieties and maintaining sufficient diversity to lower the risks of catastrophic infection. The paper uses a simple ecology-based model of endogenous disease to indicate how a local decision to plant more of a wide ly grown crop creates negative externalities by increasing the probability that new pathogens will evolve to attack the crop globally. Society's basic issue concerns where to locate on an efficiency frontier between economic profitability and a standard formula for ecological entropy-proved here to be a rigorous measure of "generalized resistance'' to crop-ecosystem failur e.