Pest Externalities from Agricultural Inputs

Agricultural inputs such as water, pesticide, and even time may have the unintended effect of stimulating some pest populations, leading to crop losses. A conceptual model is developed to contrast optimal use of pesticide and nonpesticide inputs with myopic use patterns which ignore pest externalities. Under most conditions, optimal management is found to entail reduced input levels. These issues are illustrated for Imperial Valley cotton using biological simulation. Correct calculation of the relative profitability of conventional and integrated pest management techniques, such as a shortened growing season, are found to depend crucially on whether pest externalities are taken into account.