Does the supplemental nutrition assistance program really increase obesity? The importance of accounting for misclassification errors


The prevalence of obesity among US citizens has grown rapidly over the last few decades, 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). Previous results on the effect of SNAP participation on obesity are mixed. These findings are however based on the assumption that participation status can be accurately observed, despite significant misclassification errors reported in the literature. Using propensity score matching, we conclude that there seems to be a positive effect of SNAP participation on obesity rates for female participants and no such effect for males, a result that is consistent with several previous studies. However, an extensive sensitivity analysis reveals that the positive effect for females is sensitive to misclassification errors and to the conditional independence assumption. Thus analogous findings should also be used with caution unless examined under the prism of classification errors and of other assumptions used for the identification of causal parameters.

Journal of Applied Statistics
Andreas C. Drichoutis
Andreas C. Drichoutis
Associate Professor of Consumer Behavior

My research interests are focused on, but not limited to, the economics of nutrition/obesity, contingent valuation and experimental auctions methods to elicit consumers’ valuations, choice under risk, inter-temporal decision making and applied demand analysis. Most of my research applies experimental economics methods to answer questions relevant for agricultural economists and decision scientists.