Identifying the Effects of Food Stamps on Child Health Outcomes When Participation is Endogenous and Misreported

The literature assessing the efficacy of the Food Stamp Program, now called the Supplemental Nutrition Assistance Program (SNAP), has long puzzled over positive associations between food stamp receipt and various undesirable health outcomes such as food insecurity. Assessing the impact of food stamps on outcomes is made difficult by endogenous selection into food stamp recipiency and extensive systematic misreporting of participation status. Using data from the National Health and Nutrition Examination Survey (NHANES), we apply and extend partial identification bounding methods to account for these two identification problems in a single unifying framework. Imposing relatively weak nonparametric assumptions on the selection and reporting error processes, we provide informative bounds on the impact of food stamps on child food insecurity, obesity, general health, and anemia. We find that commonly cited negative relationships between food stamps and health outcomes provide a misleading picture about the impact of the program. Without imposing any parametric assumptions, our tightest bounds identify modest favorable impacts of food stamps on child health.[...]