State‐mandated school‐based BMI assessments and self‐reported adolescent health behaviors

I provide novel evidence on the role of imperfect information in shaping childhood obesity. Between 2003 and 2017, 24 states began requiring schools to perform Body Mass Index assessments on students. Using the 1991 to 2017 National and State Youth Risk Behavior Surveys and a stacked difference‐in‐differences identification strategy, I show that these state‐mandated school‐based BMI assessments were associated with an increase in the likelihood that teens described themselves as overweight and reported that they were trying to lose weight. The relationship was most pronounced for overweight teens, suggesting that the assessments improved awareness about BMI status among this group, though I also find that non‐overweight teen girls were subsequently more likely to incorrectly describe themselves as overweight. While I do not detect meaningful changes in exercise or calorie‐limiting behaviors, I do find that these state‐mandated school‐based BMI assessments were associated with a modest reduction in BMI.