"Billions and Billions Served" Heterogenous Effects of Food Source on Child Dietary Quality

Early decisions in human capital accumulation have direct consequences on the productivity of future investments. Skills related to health capital, for example, quickly accumulate early on in life and have persistent impacts throughout adolescence and adulthood. Therefore, it is of no surprise that the case for investing early in children, specifically the disadvantaged, is strong (Heckman and Masterov, 2007), and policymakers are particularly interested in programs that target such children. With nutrition in mind, two longstanding Federal programs have gained increasing attention in the United States: the School Breakfast Program (SBP) and the National School Lunch Program (NSLP).

Offered in over 100,000 public and non-profit institutions, the SBP and NSLP serve over 30 million students every school day. Together, these two Federally subsidized meal programs represent a substantial and repeated exposure to nutrition skill formation, which has strong implications for nutrition capital accumulation. Outside of school and home, exposure to food-away-from-home (FAFH), such as fast-food and restaurant establishments, has become much more prominent in the daily diet of American children. While the literature generally agrees that FAFH negatively impacts health, researchers are at odds with respect to the impact of school food. The findings of this paper suggest that the conflicting results may be due to a focus on the average effect.

This study adds to the current literature by considering heterogeneous effects of food source across all levels of underlying dietary quality, rather than focusing on average diet quality. I focus on dietary quality because it correlates with body weight (Jennings et al., 2011) and academic achievement (Florence, Asbridge and Veugelers, 2008) in children, is a predictor for many chronic diseases in adulthood (Chiuve et al., 2013) and is at the forefront of Federal and State policies aimed at reforming nutritional standards in schools.

I define dietary quality as a child's "proneness" to consume a healthful diet using a widely used measure, the Healthy Eating Index-2005. For example, a child that is prone to a very low quality diet, possibly due to parental or environmental factors, may exhibit large benefits from a school lunch and/or breakfast. Children prone to high quality diets, on the other hand, may experience decreases in dietary quality due to the consumption of school meals. This insight makes examining the the average treatment effect (ATE) of participating in school food programs rather unappealing.

This paper uses a quantile estimator designed for panel data developed by Powell (2012). Within-individual variation over two non-consecutive days of food intake are used to identify quantile treatement effects on the distribution of dietary quality. Food from school is found to have both significantly positive effects at low quantiles and significantly negative effects at high quantiles, indicating substantial heterogeneity. While food consumed under the SBP and NSLP may not benefit every child (especially at the mean), it does improve the diets of many children whom otherwise would have poorer dietary quality. The implication is that U.S. schools are fertile grounds to improve nutrition skill formation, especially for the most nutritionally disadvantaged.