Agricultural pests as common property: Control of the corn rootworm

Insecticide resistance is an increasingly widespread problem reducing effectiveness and necessitating a switch to more expensive controls. A common property resource model is used to describe potential gain from internalizing resistance externalities through regional coordination. A nonlinear programming model of an Illinois cash grain farm is used to estimate the gain for corn rootworm control where rotation to soybeans is an alternative to insecticide. Switching to rotation as resistance builds causes a relatively minor decrease in profits because soybeans are profitable. Gain from delaying resistance is slight. Co-states give price changes necessary to alter externality production.