Economic Research Service, United States Department of Agriculture, 1800 M St NW, Washington, DC 20036, USA.
Public Health Nutr. 2012 May;15(5):811-7. doi: 10.1017/S1368980011002709. Epub 2011 Oct 13.
To estimate the effect of the US Supplemental Nutrition Assistance Program (SNAP) on the food security (consistent access to adequate food) of recipients, net of the effect of the self-selection of more food-needy households into the programme.
The food security of current SNAP recipients and recent leavers is compared in cross-sectional survey data, adjusting for economic and demographic differences using multivariate logistic regression methods. A similar analysis in 2-year longitudinal panels provides additional control for selection on unobserved variables based on food security status in the previous year.
Household survey data collected for the US Department of Agriculture by the US Census Bureau.
Households interviewed in the Current Population Survey Food Security Supplements from 2001 to 2009.
The odds of very low food security among households that continued on SNAP through the end of a survey year were 28 % lower than among those that left SNAP prior to the 30-d period during which food security was assessed. In 2-year panels with controls for the severity of food insecurity in the previous year, the difference in odds was 45 %.
The results are consistent with, or somewhat higher than, the estimates from the strongest previous research designs and suggest that the ameliorative effect of SNAP on very low food security is in the range of 20-50 %.
估计美国补充营养援助计划(SNAP)对接受者的食品安全(稳定获得充足食物)的影响,扣除更需要食物的家庭自我选择进入该计划的影响。
使用多变量逻辑回归方法,在横断面调查数据中比较当前 SNAP 接受者和最近离开者的食品安全状况,调整经济和人口差异。在两年期纵向面板中进行类似的分析,根据前一年的食品安全状况,对不可观测变量的选择提供了额外的控制。
美国人口普查局为美国农业部收集的家庭调查数据。
2001 年至 2009 年接受美国人口普查局当前人口调查食品安全补充调查的家庭。
在调查年度结束前,继续参加 SNAP 的家庭中非常低的食品安全的几率比在评估食品安全的 30 天前离开 SNAP 的家庭低 28%。在控制前一年食品安全严重程度的两年期面板中,几率差异为 45%。
结果与之前最强的研究设计的估计一致,或略高,表明 SNAP 对非常低的食品安全的改善效果在 20-50%之间。