Do Class Size Reductions Protect Students from Infectious Diseases?

We evaluate the causal effect of class size (number of students in a classroom) on incidence of class closure due to the flu, as an outcome of an infectious disease epidemic. For identification of causal effects, we apply a regression discontinuity design using discontinuous variation of class sizes, around the class size cap set by regulation, to administrative data of public primary and middle school students in one of the largest municipalities within the Tokyo metropolitan area from 2015 to 2017. Most classrooms in Japan are constructed in accordance with a standard of classroom area, 63 square meters;class size reduction improves social distancing among students in a classroom. We find that class size reduction is effective in reducing class closures due to the flu: a one-unit reduction of class size decreases class closure by about 5 percent. Additionally, forming small classes with 27 students at most, satisfying the social distancing of 1.5 meters recommended to prevent droplet infection including influenza and COVID-19, reduces class closure by about 90 percent. Moreover, we find that the older the students, the larger the effects of class size reduction. Our findings provide evidence for the effectiveness of social distancing policy in primary and middle schools to protect students from droplet infectious disease spread, including COVID-19.

Do macroeconomic shocks in the local labor market lead to child maltreatment and death?: Empirical evidence from Japan.

BACKGROUND: Japan is facing a rapid increase in the number of reported child maltreatment cases. Child maltreatment has long-term consequences for the victims, and unemployment rate is considered a strong predictor of it. However, only few studies have analyzed the causal relation between child maltreatment and the unemployment rate-particularly the effects of the latter on the former-in Japan. METHODS: Using prefecture-level longitudinal data from 2005 to 2016, we employed a fixed effects instrumental variable estimation. The estimation included a weighted average of the national unemployment rate across industries by industrial structures in 2005 as an instrument to identify the causal effects. RESULTS: The average local unemployment rate changed by approximately 50% from the peak to the bottom in the sample period. A 50% increase in local unemployment rates increased the number of reported child neglect cases and child deaths by 80% and 70% (statistically significant at the 5% level), respectively. Further, it increased cases of death due to external causes, unintentional injuries, and unintentional drowning by 146%, 217%, and 315% (statistically significant at the 5% level), respectively. CONCLUSION: The local unemployment rate is a risk factor for child maltreatment, resulting in children's death, especially as a result of unintentional drowning-the common cause of death due to child neglect. When the local unemployment rates rise, governments should allocate more financial and human resources for preventive measures to combat child deaths caused by neglect.

COVID-19's Lockdown and Crime Victimization: The State of Emergency under the Abe Administration

Abstract COVID-19 has led many governments to impose lockdowns in efforts to reduce the spread of the virus. One of the many consequences of the lockdown is a reduction in crime. We apply a difference-in-differences approach to the 2018?2020 Crime Statistics to investigate the effect of the 2020 lockdown on crime victimization in Japan. We find that the 2020 lockdown leads to 12.7% and 20.9% declines in violent and property crime victimization rates per 100,000 people, respectively. Moreover, we observe that premeditated crimes, such as breaking-and-entering and sexual assault, decline more than non-premeditated crimes, such as homicide. We also explore the heterogeneous effects of the lockdown by age groups. We observe that there is a significant decline in sexual assault victimization for those between the ages of 0 and 29, and there are significant declines in overall violent and property crime victimizations and their subtypes for those between ages of 30 and 59. Finally, we show that there is an improvement in suicide rates, which suggests that better mental health is the mechanism partially mediating the relationship between lockdown and crime victimization.