摘要：This study estimated a dynamic logistic model to explain the diffusion Bt cotton in the United States. Regional differences in the speed and extent of Bt cotton adoption were explained by differences in availability of Bt seed adapted to local conditions, potential seed supplier profits, and economic variables affecting grower gains from adoption. The study also estimated the impact of Bt cotton on insecticide use, controlling for differences in pest infestations and prices and correcting for the endogeneity of the Bt adoption decision. Bt cotton significantly reduced insecticide applications to control target pests cotton bollworm, tobacco budworm, and pink bollworm. Bt cotton has led to an overall reduction in these applications per total US cotton acres, ranging from 0.5 in 1996 to 1.8 in 2003. Reductions in applications per infested acres ranged from 0.67 to 2.3.
