Nikulkov Alex, Barrett Christopher B, Mude Andrew G, Wein Lawrence M
Graduate School of Business, Stanford University, Stanford, California, Unites States of America.
Charles H. Dyson School of Applied Economics and Management, Cornell University, Ithaca, New York, United States of America.
PLoS One. 2016 Dec 20;11(12):e0168432. doi: 10.1371/journal.pone.0168432. eCollection 2016.
The U.S. is the main country in the world that delivers its food assistance primarily via transoceanic shipments of commodity-based in-kind food. This approach is costlier and less timely than cash-based assistance, which includes cash transfers, food vouchers, and local and regional procurement, where food is bought in or nearby the recipient country. The U.S.'s approach is exacerbated by a requirement that half of its transoceanic food shipments need to be sent on U.S.-flag vessels. We estimate the effect of these U.S. food assistance distribution policies on child mortality in northern Kenya by formulating and optimizing a supply chain model. In our model, monthly orders of transoceanic shipments and cash-based interventions are chosen to minimize child mortality subject to an annual budget constraint and to policy constraints on the allowable proportions of cash-based interventions and non-US-flag shipments. By varying the restrictiveness of these policy constraints, we assess the impact of possible changes in U.S. food aid policies on child mortality. The model includes an existing regression model that uses household survey data and geospatial data to forecast the mean mid-upper-arm circumference Z scores among children in a community, and allows food assistance to increase Z scores, and Z scores to influence mortality rates. We find that cash-based interventions are a much more powerful policy lever than the U.S.-flag vessel requirement: switching to cash-based interventions reduces child mortality from 4.4% to 3.7% (a 16.2% relative reduction) in our model, whereas eliminating the U.S.-flag vessel restriction without increasing the use of cash-based interventions generates a relative reduction in child mortality of only 1.1%. The great majority of the gains achieved by cash-based interventions are due to their reduced cost, not their reduced delivery lead times; i.e., the reduction of shipping expenses allows for more food to be delivered, which reduces child mortality.
美国是世界上主要通过跨洋运输以实物形式提供粮食援助的国家。这种方式比现金援助成本更高且及时性更差，现金援助包括现金转移、食品券以及在受援国或其附近采购食品的当地和区域采购。美国的这种方式因一项要求而加剧，即其跨洋粮食运输的一半需要由悬挂美国国旗的船只运送。我们通过制定和优化供应链模型来估计这些美国粮食援助分配政策对肯尼亚北部儿童死亡率的影响。在我们的模型中，选择跨洋运输的月度订单和现金干预措施，以在年度预算约束以及现金干预措施和非美国国旗运输的允许比例的政策约束下，将儿童死亡率降至最低。通过改变这些政策约束的严格程度，我们评估了美国粮食援助政策可能的变化对儿童死亡率的影响。该模型包括一个现有的回归模型，该模型使用家庭调查数据和地理空间数据来预测社区中儿童的上臂中部周长Z评分均值，并允许粮食援助提高Z评分，以及Z评分影响死亡率。我们发现，现金干预措施是比美国国旗船只要求更有力的政策杠杆：在我们的模型中，转向现金干预措施可将儿童死亡率从4.4%降至3.7%（相对降低16.2%），而在不增加现金干预措施使用的情况下取消美国国旗船只限制，儿童死亡率仅相对降低1.1%。现金干预措施取得的大部分收益归因于其成本降低，而非交付提前期缩短；即运输费用的降低使得能够运送更多粮食，从而降低了儿童死亡率。
