中文摘要：BT棉花是农业低收入国家最广泛种植的转基因作物之一，众多研究都证明了BT棉花所具有的优点，但是BT毒素的有效性有一定的技术限制，比如异质性。由于巴基斯坦在BT棉花监管、种子质量控制方面较薄弱，本文选择可靠的BT棉花来对其生产力进行评估，并引入品种名称、批准状态、农民信仰、植物组织实验室检测、测量BT毒素有效性的生物物理实验等指标来进行判定；在不将BT作为减少损害的工具的标准生产模型中，只有农民信仰影响棉花产量；而在损害控制框架中，所有的BT指标均可以减少害虫危害；生物物理实验指标的影响最大，但官方批准最弱；因此，对于决策者而言，在伦理和生产力的基础上，改进品种信息、监控品种销售极为必要。
外文摘要：Bt cotton remains one of the most widely grown biotech crops among smallholder farmers in lower income countries, and numerous studies attest to its advantages. However, the effectiveness of Bt toxin, which depends on many technical constraints, is heterogeneous. In Pakistan, the diffusion of Bt cotton occurred despite a weak regulatory system and without seed quality control; whether or not many varieties sold as Bt are in fact Bt is also questionable. We utilize nationally representative sample data to test the effects of Bt cotton use on productivity. Unlike previous studies, we invoke several indicators of Bt identity: variety name, official approval status, farmer belief, laboratory tests of Bt presence in plant tissue, and biophysical assays measuring Bt effectiveness. Only farmer belief affects cotton productivity in the standard production model, which does not treat Bt appropriately as damage-abating. In the damage control framework, all Bt indicators reduce damage from pests. Biophysical indicators have the largest effect and official approval has the weakest. Findings have implications for impact measurement. For policy-makers, they suggest the need, on ethical and productivity grounds, to improve variety information and monitor variety integrity closer to point of sale.
外文关键词：Bt cotton, damage abatement, Pakistan, pesticides, productivity
作者：Ma, Xingliang; Smale, Melinda; Spielman, David J.; Zambrano, Patricia; Nazli, Hina; Zaidi, Fatima
作者单位：Michigan State Univ, E Lansing, MI 48824 USA.
期刊名称：JOURNAL OF AGRICULTURAL ECONOMICS
期刊影响因子：1.795
出版年份：2017
出版刊次：2
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