Using Machine Learning to Estimate the Heterogeneous Effects of Livestock Transfers
评估危地马拉一个提供本地鸡种培训和转移的项目，发现对家庭消费和营养的平均效果不显著，但显著降低了女童发育迟缓，且机器学习显示最贫困家庭在饮食质量和动物蛋白消费上受益最大。
We evaluate a program in Guatemala offering training and transfers of a local chicken variety using a randomized phase‐in design with imperfect compliance. We do not find strong evidence for or against positive average intent‐to‐treat effects on household‐level outcomes, including indicators of expenditure, calorie and protein intake, diet quality, egg consumption and production, as well as chicken ownership and management. Among girls between the ages of six and sixty months, we find that the program reduced stunting by 23.5 (± 19.4) percentage points while also improving other height and weight outcomes. Boys are more likely to suffer from intestinal illness, which could explain differences in program impacts by gender. Using machine learning methods, we show that the poorest households enjoyed the largest impacts on diet quality and animal protein consumption, whereas children in the poorest households experienced the largest impacts on the probability of consuming animal source foods. Larger effects on animal source food consumption among children in relatively poor households did not translate into greater impacts on height or weight.