Prior research has shown that time spent in school does not close the achievement gap between students with low and high socioeconomic status (SES). We examine the effect of combining increased instruction time with information to teachers about their students' reading achievements by using a...

What appears to be ineffectiveness of educational interventions in the long run may actually be caused by statistical artefacts in the equating of tests taken at different time points or by the nature of the skill development in the absence of targeted interventions. We use longitudinal data on...