Abstract
This article gives an overview of the empirical studies of the determinants of students' academic performance in Japan. Recent development in the availability of achievement data have enabled researchers, including economists, to identify the determinants of education outcomes. Economists have great curiosity about the determinants of students' academic achievement because achievement gaps among school-age children result in future income inequality. Education production functions are estimated using student-level achievement data for Japanese students, with emphasis on estimating the effect of ability grouping. The empirical results show that students' test scores are strongly affected by family backgrounds, whereas school resource variables have a more limited impact. We cannot reject the hypothesis that the effect of reducing class size is zero. On the other hand, the effects of family backgrounds become small when students are grouped according to their ability, suggesting a possibility that schools can succeed in reducing the gaps in opportunities among students from different family backgrounds.