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 (ATE) of SNAP on child food insecurity, poor general 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.

Standard-Nutzungsbedingungen:Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden.Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen.Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. The Institute for the Study of Labor (IZA) in Bonn is a local and virtual international research center and a place of communication between science, politics and business. IZA is an independent nonprofit organization supported by Deutsche Post Foundation. The center is associated with the University of Bonn and offers a stimulating research environment through its international network, workshops and conferences, data service, project support, research visits and doctoral program. IZA engages in (i) original and internationally competitive research in all fields of labor economics, (ii) development of policy concepts, and (iii) dissemination of research results and concepts to the interested public. Terms of use: Documents inIZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper should account for its provisional character. A revised version may be available directly from the author. The higher value of the line in US dollars reflects the fact that the new PPPs yield a relatively lower purchasing power of that currency vis-à-vis those of most poor countries. Because the line was designed to preserve real purchasing power in poor countries, the revisions lead to relatively small changes in global poverty incidence: from 14.5 percent in the old method to 14.1 percent in the new method for 2011. In 2012, the new reference year for the global count, we find 12.7 percent of the world's population, or 897 million people, are living in extreme poverty. There are changes in the regional composition of poverty, but they are also relatively small. This paper documents the detailed methodological decisions taken in the process of updating both the poverty line and the consumption and income distributions at the country level, including issues of inter-temporal and spatial price adjustments. It also describes various caveats, limitations, perils and pitfalls of the approach taken.

CONTEXT: The prevalence of overweight (OW) among children in the United States has increased during the last three decades, but prevalence measures fail to reveal the extent to which OW children exceed the OW threshold. OBJECTIVE: To measure the amount by which OW children exceed the OW threshold. To examine the trend in this measure over the last three decades using data with measured weights and heights. DESIGN, SETTING AND PARTICIPANTS: Data used for analysis are from the National Health and Nutrition Examination Survey (NHANES) for persons between 2 and 19 y of age from 1971 to 2000. Anthropometric measures were obtained by trained health technicians, and the sample sizes range from 4037 in 1999-2000 to 10 590 in 1988-1994. MAIN OUTCOME MEASURE: The extent of OW is measured as the average amount by which each child's body mass index (BMI) exceeds their age and gender-specific OW threshold. This measure is examined by sex, age group and race/ethnicity. The OW threshold for those aged 2-19 y is defined as at or above the 95th percentile of the sex-specific BMI for age growth charts. RESULTS: The extent of child OW has been increasing faster than the prevalence of child OW for all classifications considered in this paper, including the analysis by age, sex, race and ethnicity. The prevalence of OW for children aged 2-19 y increased by 182% between 1971-1971 and 1999-2000, while the extent of OW increased by 247% over the same time period. CONCLUSIONS: Unlike prevalence measures, the measure of the extent of child OW is sensitive to changes in the BMI distribution of the overweight. This analysis reveals that not only have more children become OW in the last three decades, but OW children have been getting heavier.

The Policy Research Working Paper Series disseminates the findings of work in progress to encourage the exchange of ideas about development issues. An objective of the series is to get the findings out quickly, even if the presentations are less than fully polished. The papers carry the names of the authors and should be cited accordingly. The findings, interpretations, and conclusions expressed in this paper are entirely those of the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank and its affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent.

No abstract