The Effect of Class Size Reduction on Bullying, Violent Behavior, and Truancy

The "class size reduction" in compulsory education is becoming controversial in Japan with a sharp decrease in the number of school-aged children and under strong pressure to reduce fiscal deficits. The literature investigated the causal effect of the class size reduction on student achievements, while the policy circle has been interested in whether or not class size reduction helps mitigate the growing problems at school, such as bullying, violent behavior, and truancy. This paper thus empirically examines whether class size matters in reducing bullying, violent behavior, and truancy by using discontinuous changes in class size under the Japanese public compulsory education system. Using a unique school-level micro dataset provided by anonymous local governments in the Kanto metropolitan areas, our result show that class size reduction affects bullying in primary education, while there is no evidence that class size affects violent behavior and truancy in primary and secondary education.