Intrahousehold flypaper effects — Quasi-experimental evidence from a randomized school-feeding program in rural northwestern China

Abstract This paper estimates intrahousehold flypaper effects using data from a school-based randomized nutrition intervention that aimed to reduce anemia prevalence among primary schoolers in rural northwestern China. Since randomized treatment assignment ensures that preexisting boarder–nonboarder differences in diet are statistically similar between treatment and control schools, boarder–nonboarder comparisons of treatment-control differences in students’ nutritional outcomes offers an alternative Difference-in-Differences research design allowing us to estimate credible flypaper effects. Using diet diversity of boarders in the treatment group (who presumably consumed most of the project-provided food) as a benchmark, we found that the gain in diet diversity of treated nonboarders due the intervention was reduced by more than 70% at home, which led to a significant loss of at least 4.4 g/L in their gain in Hemoglobin levels.