Does the reduction in instruction time affect student achievement and motivation? Evidence from Japan

This paper examines how instruction time affects students’ cognitive ability and motivation. It uses data obtained from the responses of 4th-grade Japanese students from the international academic survey “Trends in International Mathematics and Science Study.” The study estimates a fixed effects model using within-student between-subject variation, which, in 2002, caused a reduction in instruction time due to the revision of curriculum guidelines in Japan. To remove teachers’ fixed effects, the sample was restricted to students taught by the same teacher. The results demonstrate that instruction time positively affects student test scores and two out of three motivation variables (Like and Positive). This result suggests that the 2002 educational reform negatively impacted students’ cognitive and non-cognitive abilities. Further, instruction time had different effects on test scores and motivation variables (Like and Positive) for students’ and teachers’ gender. Additionally, instruction time also positively impacted scores and motivation variables (Like, or Like and Positive) in combination with teachers who had experience of ten or more years and students who had time to study at home.