Long-term Heterogeneous Effects of a Mega Natural Disaster on Physical Health Capital Accumulation among School-aged Children (Japanese)

An unexpected mega natural disaster that dramatically changes the living environment disrupts educational opportunities for school-aged children, which has a significant negative effect on the cognitive and non-cognitive skills and educational achievement necessary for human capital development. However, little attention has been paid to the impact on their physical health of the reduction in physical activity opportunities that are simultaneous side-effects of the disaster. Given the positive correlation between academic and athletic performance, the educational returns from the negative shocks resulting from a mega disaster may have been underestimated. This study uses individual data including detailed athletic ability from government statistics to estimate the impact of a local mega natural disaster on the development and athletic performance among school-aged children. Using a difference-in-differences approach, the results show that the disaster has little overall effect on children’s development but significantly increases their bodyweight and obesity in the specific areas where more stricter restrictions on outdoor activity were imposed. These effects persist even after terminating the severe restrictions. I also find that the disaster has significantly negative average treatment effects on athletic performance, but that such effects are temporary, with limited long-term effects. Moreover, the negative effects on physical health capital accumulation are consistent with the literature on the fetal origin hypothesis and on early health shocks in the life course. This evidence strongly suggests that athletic performance during school age would be an important confounder in the causal inference models on educational achievement and its return for future socioeconomic outcomes.