Does the Food Stamp Program Really Increase Obesity? The Importance of Accounting for Misclassification Errors

Over the last few decades, the prevalence of obesity among US citizens has grown rapidly, especially among low-income individuals. This has led to questions about the effectiveness of nutritional assistance programs such as the Supplemental Nutrition Assistance Program (SNAP), formerly known as the Food Stamps Program (FSP). Results from previous studies generally suggest that FSP participation increases obesity. This finding is however based on the assumption that participants do not misclassify their program participation despite significant misclassification errors reported in the literature. Using propensity score matching and a new method to conduct extensive sensitivity analysis, we conclude that this finding is sensitive to misclassification errors above 10% and to the conditional independence assumption.