Growing Up Poor and Childhood Weight Problems

This paper investigates the impact of growing up in poverty on the risk of childhood weight problems. Understanding the effect of family income on childhood weight problems is important, but has been hindered by the potential endogeneity of family income. We use matched mother-child data from the National Longitudinal Survey of Youth (NLSY) to study the effects of growing up poor on risks of childhood overweight and underweight, accounting for unobserved heterogeneity that governs both children’s weight and family income. We also estimate the impacts of family income on a child’s weight measured by Body Mass Index (BMI) at different points in the conditional distribution of children’s weight, using a two-stage residual inclusion least absolute deviation approach. Our results show that the mean effects of poverty exposure on risks of obesity and underweight are not statistically different from zero, accounting for the endogeneity of family income. More importantly we find that growing up poor increases a child’s BMI by 14.7 percent if her BMI is at the 90th quantile of her cohort’s BMI distribution and reduces her BMI by 12.7 percent if her BMI is at the 10th quantile. JEL classifications: I1 I3 Growing Up Poor and Childhood Weight Problems