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Brent Kreider's research
Identifying the Effects of Food Stamps on Child
Health Outcomes
When Participation is Endogenous and Misreported
Brent Kreider, Iowa State University
John V. Pepper, University of Virginia
Craig Gundersen, University of Illinois
Dean Jolliffe, World Bank
Abstract. The
literature assessing the efficacy of the Supplemental Nutrition Assistance
Program (SNAP), formerly known as the Food Stamp Program, has long puzzled over
positive associations between SNAP receipt and various undesirable health
outcomes such as food insecurity. Assessing the causal impacts of SNAP, however,
is hampered by two key identification problems: endogenous selection into
participation and extensive systematic underreporting of participation status.
Using data from the National Health and Nutrition Examination Survey (NHANES),
we extend partial identification bounding methods to account for these two
identification problems in a single unifying framework. Specifically, we derive
informative bounds on the average treatment effect of SNAP on child food
insecurity, general poor health, obesity, and anemia across a range of different
assumptions used to address the selection and classification error problems. In
particular, to address the selection problem we apply relatively weak
nonparametric assumptions on the latent outcomes, selected treatments, and
observed covariates. To address the classification error problem, we formalize a
new approach that uses auxiliary administrative data on the size of the SNAP
caseload to restrict the magnitudes and patterns of SNAP reporting errors.
Layering successively stronger assumptions, an objective of our analysis is to
make transparent how the strength of the conclusions varies with the strength of
the identifying assumptions. Under the weakest restrictions, there is
substantial ambiguity: we cannot rule out the possibility that SNAP increases or
decreases poor health. Under stronger but plausible assumptions used to address
the selection and classification error problems, we find that commonly cited
relationships between SNAP and poor health outcomes provide a misleading picture
about the true impacts of the program. Our tightest bounds identify favorable
impacts of SNAP on child health.