Association for Public Policy Analysis & Management

The goal of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is to support the health and well-being of low-income women, infants, and children by providing pregnant women and children up to five years old with access to nutritious food. While the health benefits of WIC for young children have been well studied (Cole & Fox, 2008; Mackey-Bilaver, 2007), its potential non-health benefits, including improvements in children’s early cognitive and socio-emotional wellbeing, have been practically unexplored. The one study to examine non-health outcomes found that prenatal WIC exposure predicted better cognitive outcomes at age 2 and educational outcomes at age 11 (Jackson, 2015). The goal of the present study is to expand that work by examining associations between WIC during early childhood (ages 0 – 5) and a broad set of cognitive and behavioral outcomes at school entry, between ages 5 and 7.

Data are drawn from the National Longitudinal Survey of Youth – Child Study (NLSY-CS) (N = 5,095) and are analyzed using comparisons across siblings to address the substantial bias associated with families’ selection into the WIC program. To capture WIC use, we compute a ratio of reported WIC receipt at each parent interview between child ages 0 and 5 relative to the number of times parents were asked about WIC use during that period. Across models, we regress each child outcome on WIC exposure and a series of child-level covariates in a sibling fixed effects framework. The Peabody Picture Vocabulary Test (PPVT) and math and reading subscales of the Peabody Individual Achievement Test (PIAT) are used to measure cognitive skills, and the internalizing and externalizing behavior problems, hyperactivity, and total behavior problems subscales of the Behavior Problems Index (BPI) are used to measure socioemotional skills. All child outcomes are taken from the first available score between the ages of 5 and 7, to most closely represent skills present at school entry.

Results of the sibling fixed effects models suggest that WIC use is unassociated with children’s cognitive outcomes but predicts lower total behavior problems (B = -3.304, SE = 1.620, p < 0.05), and internalizing behaviors (B= -4.457, SE = 1.719, p < 0.001) specifically, at school entry. These results suggest that after accounting for family level variation, WIC is associated with modest decreases in behavioral problems, between 15 to 20% of a standard deviation.

This study is the first to document the association between WIC participation and decreased behavior problems using sibling models to account for families’ selection into WIC. While we did not find evidence of an association between WIC and cognitive outcomes at school entry, the effect of WIC on behavioral problems is both statistically significant and meaningful in magnitude. While the relationship between WIC participation and health outcomes is widely documented, these findings suggest the benefits of WIC extend beyond health outcomes to include outcomes important to children’s early school success.