The Effects of the Food Stamp Program on Energy Balance and Obesity

The Food Stamp Program (FSP) administered by the U.S. Department of Agriculture (USDA) is the cornerstone of the U.S. federal income and food safety-net policy. The FSP has subsidized the food budget for millions of American households for over forty years, spending more than ;In this dissertation I develop new conceptual and empirical models linking FSP participation, calorie consumption, physical activity, and weight gain, while controlling for genetic variation, weight history, and other physiological characteristics of individuals. The models enable us to test whether participants gained more weight, ate more calories, or engaged less in physical activity; or if previously omitted variables and individual health characteristics explain the higher prevalence of obesity among female FSP participants. In addition, I investigate the possibility that individual propensities for obesity influence the decision to participate in the FSP. To do so, I construct a model that allows body weight to influence the choice to participate in the FSP and then use an instrumental variables (IV) framework to identify the local average treatment effect (LATE) of body weight on the probability of FSP participation.;I do not find a positive and significant relationship between FSP participation and weight gain for women. More specifically, I do not find convincing evidence for the hypothesis that FSP participation causes obesity by increasing caloric consumption, decreasing physical activity, or some combination of the two. The results from the IV model estimation contribute new insights into the personal and household characteristics that influence the decision to participate in the FSP and corroborate the findings in previous studies. The results suggest that a positive association between FSP and weight exists, but I find no evidence of a causal link from one to the other. Rather, the IV results suggest that omitted variables likely contribute to a higher body weight and a greater propensity to participate in the FSP. This research has demonstrated the difficulty of identifying a causal link between FSP participation and obesity, in part because the decision to participate in the FSP likely depends on many factors that the econometrician will never observe. I find no justification for making changes to the FSP on the grounds that FSP participation causes weight gain.