This article reports the findings of an analysis into the effect of one year's schooling for 15-year-olds in England on reading performance, reading engagement, and reading activities. The analyses were done on PISA 2000 data by applying a regression discontinuity approach within a multilevel framework. The effect of schooling is estimated as the difference between students from two consecutive grades minus the effect of age. A remarkably modest effect on reading performance was found, and no significant effects were found for the other two measures. The effect on reading performance was found to be somewhat stronger in schools with disadvantaged student populations. (Contains 5 tables, 2 figures, and 3 notes.)