Abstract
This study examines the effect of extra-school educational investment at an early age upon the study hours of high school students. The result of Tobit analysis shows that the experience of participating in shadow education at an early age (when the respondent was in elementary school) positively affects student study hours net of other variables including whether or not he/she has participated in shadow education after going on to high school. This result suggests that extra-school educational investment at an early age contributes to enhance student's ability that enables to study longer outside school.
