Estimating the Effect of School Time of Instruction on Student Achievements
Hebrew University Economics Working Paper No. 01-4
35 Pages Posted: 4 Nov 2001
Date Written: August 2001
The renewed focus on the importance of human capital for social development and economic growth, and the recently published evidence on wide international disparities in student achievements, have led to a new interest in the determinants of schooling quality. This paper evaluates the effect on student achievement of an important school input, schooling hours, and compares its effect and cost to that of class size. To overcome the fact that the levels of these inputs are functions of students' ability and past achievement, I use instrumental variables that are derived from two allocation rules that partly determine the level of weekly instruction hours and class size in Israeli primary schools. The instrumental variable results suggest that increasing instruction hours and reducing class size have significant effects on students' achievements. The OLS results, in contrast, show no (or perverse) effects of both inputs on achievement. The cost equivalent tradeoff between instruction hours and class size suggest that it is more cost effective, at the margin, to augment school time than to reduce class size. These results are relevant for assessing recent educational reforms in the U.S. and the U.K. that focus solely on class-size reduction.
Keywords: school time, class size, student achievements, causal identification
JEL Classification: I0, I2, J0, J3
Suggested Citation: Suggested Citation