Modelling of Bt Corn Production under Choice of Abatement Specification

For modelling Bt corn production, we proposed a joint abatement function to capture pest life cycle. Simulation of pest adaptation to popular Bt corn varieties was developed and applied to generate random sample of abatement, where in-field parameters were adopted in favor of practical corn production. On the basis, logistic model was used to fit the sample data. The estimates were compared to those from exponential model for choice of abatement specification. At last, Cobb-Douglas production model was integrated with the pre-estimated abatement function along with farm level data and distribution of corn growers’ choices, where instrument variables estimator and delta method were adopted to solve simultaneity problem induced by farm level data. The estimated marginal net return was positive, suggesting that Bt corn as pesticide is underutilized. However, the value kept decline in recent three years. We attributed the decline of marginal net return to the widespread adoption of new Bt corn varieties with blended refuge, and the insect resistance management would benefit from it.