Gebre Girma Gezimu, Mawia Harriet, Makumbi Dan, Rahut Dil Bahadur
Faculty of Environment, Gender and Development Studies College of Agriculture Hawassa University Hawassa Ethiopia.
International Maize and Wheat Improvement Center (CIMMYT Nairobi Kenya.
Food Energy Secur. 2021 Nov;10(4):e313. doi: 10.1002/fes3.313. Epub 2021 Jul 9.
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.
生物技术和其他植物育种举措所带来的科学进步推动了生产力增长，这为满足全球不断增长的粮食需求带来了巨大希望。这证明了对农业研发进行投资的合理性，这些投资促使非洲培育出了耐逆性玉米品种（STMVs）。虽然大多数文献记录了耐逆性玉米品种对生产力的平均影响，但本文基于这样一个事实：不同家庭采用技术所获得的收益并不相同。本文通过对来自坦桑尼亚的720个玉米种植户样本进行研究，考察采用耐逆性玉米品种在产量、收入和粮食安全收益方面的潜在异质性，以此填补这一信息空白。采用由内生转换概率模型支持的剂量反应连续处理效应方法，来估计采用耐逆性玉米品种对三个感兴趣结果的异质性影响。结果表明，总体而言，采用耐逆性玉米品种使玉米谷物产量提高了约1吨/公顷，玉米收入增加了约62美元/公顷。采用耐逆性玉米品种还分别将报告轻度、中度和重度粮食不安全的倾向降低了34%、17%和6%。根据采用规模的不同，在生产力、收入和粮食安全效应方面存在显著的个体差异，在较低采用剂量水平下影响更大。耐逆性玉米品种采用的异质性和亲贫性质还通过非参数结果得以揭示，这些结果表明，在财富和知识禀赋较低的家庭中，生产力收益更高。这些发现强调了进一步推广耐逆性玉米品种的必要性，以便对坦桑尼亚贫困小规模农户的生计产生更大影响。
