Abstract
This study focuses on the creation mechanism of relative age effect and investigates the relationship between children's birth month and parents' (mother's) socioeconomic status and involvement in education. Previous studies have investigated the relative age effect on children's academic ability, academic achievements, and participation in sports. Unlike previous studies, this study does not investigate the direct effet of birth month on educational outcome, but instead performs quantitative research on the uninvestigated relationship between children's birth month and their mother's socioecomonic status and involvement in education. The results reveal that mothers who are enthusiastic about educational expenses tend to not have children who are born between January 1 and April 1 (end of the school year). Furthermore, this tendency differed among regions and was found mostly in regions with a high attendance rate of cram schools. This study cannot verify whether the birth month of a child is an intentional result of the parents (whether parents choose to have children in a specific month) or an unintentional result. However, the study was able to indicate the type of parents who have children that are not born at the end of the school year. This study provides a basic analysis for clarifying the critical mechanism of children's birth month.
