Productivity growth emanating from scientific advances offered by biotechnology and other plant breeding initiatives offers great promise for meeting the growing food demand worldwide. This justifies investments in agricultural research and development that have led to the development of stress-tolerant maize varieties (STMVs) in Africa. While most literature has documented the average impacts of STMVs on productivity, this paper is premised on the fact that benefits from technology adoption are not the same across household. The paper addresses this information gap by examining potential heterogeneity in yield, income, and food security benefits from of adopting STMVs using a sample of 720 maize-producing households from Tanzania. The dose-response continuous treatment effect method supported by an endogenous switching probit model was used to estimate the heterogenous impact of STMV adoption on the three outcomes of interest. Results show that, overall, the adoption of stress-tolerant maize varieties increased maize grain yield by about 1 ton/ha, maize income by about $62/ha. The adoption of STMVs also reduced the propensity to report mild, moderate, and severe food insecurity by 34%, 17%, and 6%, respectively. There are substantial idiosyncratic variations in the productivity, income, and food security effects depending on the scale of adoption, with a higher impact at lower dose levels of adoption. The heterogenous and pro-poor nature of STMV adoption is also revealed through nonparametric results showing higher productivity benefits among households that are less endowed with wealth and knowledge. These findings underscore the need for further scaling of stress-tolerant maize varieties for greater impact on the livelihoods of poor small-scale farmers in Tanzania.

中文翻译：

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采用抗逆玉米对坦桑尼亚玉米产量、玉米收入和粮食安全的影响

生物技术和其他植物育种计划提供的科学进步带来的生产力增长为满足全球不断增长的粮食需求提供了巨大的希望。这证明了对农业研发的投资是合理的，这些投资已导致非洲耐压玉米品种 (STMV) 的发展。虽然大多数文献都记录了 STMV 对生产力的平均影响，但本文的前提是，技术采用带来的好处在家庭中并不相同。本文通过使用来自坦桑尼亚的 720 个玉米生产家庭的样本，研究采用 STMV 在产量、收入和粮食安全效益方面的潜在异质性，解决了这一信息差距。使用由内源转换概率模型支持的剂量反应连续治疗效果方法来估计 STMV 采用对三个感兴趣的结果的异质影响。结果表明，总体而言，采用抗逆玉米品种可使玉米产量增加约 1 吨/公顷，玉米收入增加约 62 美元/公顷。采用 STMV 还将报告轻度、中度和重度粮食不安全的倾向分别降低了 34%、17% 和 6%。根据采用的规模，生产力、收入和粮食安全影响存在巨大的特殊差异，在采用较低剂量水平时影响更大。非参数结果也揭示了 STMV 采用的异质性和有利于穷人的性质，显示在财富和知识较少的家庭中生产率收益更高。这些发现强调了进一步扩大抗压玉米品种的必要性，以对坦桑尼亚贫困小农的生计产生更大影响。