一項刊登在PNAS上的研究發(fā)現(xiàn),，至少有一種轉基因農作物——被改造成抵御常見昆蟲害蟲的棉花——已經顯著提高了印度小型農戶家庭的生活標準,。在2002年到2008年間,，Jonas Kathage 和 Matin Qaim對印度四個主要生產棉花的邦的533戶家庭進行了調查,。這些樣本包括了種植稱為Bt棉花的轉基因作物的農民以及沒有種植它們的農民,。前一組報告說棉花產量和利潤分別增加了24%和50%,。
這組科研人員把這種增加歸結為棉鈴蟲破壞的減少,。他們進一步確定了一旦這些種植者意識到這種利潤收益是可持續(xù)的,，種植Bt棉花的農民的生活標準就提高了18%,。由于這些農民大多數(shù)相對貧窮，這組作者報告說,，這種收益已經對他們的生活產生了巨大的積極影響,。
這些發(fā)現(xiàn)反駁了早先的一個主張，即轉基因作物技術因為較低的和侵蝕性的經濟收益而可能傷害到小型農戶,。這組作者說,，由于Bt棉花是唯一一種已經被小型農戶廣泛種植的作物，這項研究可能影響更廣泛的公眾生物技術辯論,。（生物谷Bioon.com）
doi:10.1073/pnas.1203647109
PMC:
PMID:
Economic impacts and impact dynamics of Bt (Bacillus thuringiensis) cotton in India
Jonas Kathage1 and Matin Qaim1
Despite widespread adoption of genetically modified crops in many countries, heated controversies about their advantages and disadvantages continue. Especially for developing countries, there are concerns that genetically modified crops fail to benefit smallholder farmers and contribute to social and economic hardship. Many economic studies contradict this view, but most of them look at short-term impacts only, so that uncertainty about longer-term effects prevails. We address this shortcoming by analyzing economic impacts and impact dynamics of Bt cotton in India. Building on unique panel data collected between 2002 and 2008, and controlling for nonrandom selection bias in technology adoption, we show that Bt has caused a 24% increase in cotton yield per acre through reduced pest damage and a 50% gain in cotton profit among smallholders. These benefits are stable; there are even indications that they have increased over time. We further show that Bt cotton adoption has raised consumption expenditures, a common measure of household living standard, by 18% during the 2006–2008 period. We conclude that Bt cotton has created large and sustainable benefits, which contribute to positive economic and social development in India.
