Extending the school year would improve learning significantly — and widen achievement gaps, writes Seth Gershenson on Brookings’ Chalkboard.
That’s because high achievers benefit more than low achievers from additional learning time. His research is discussed in this IZA paper.
For kindergarteners in the 10th percentile of achievement, the effect of a 250-day school year is about 0.75 of a standard deviation in math, while the average effect is 1.75 SD for those in the 90th percentile, he writes. Results are similar for reading.
This raises an intriguing question. Is equality (or less inequality) more important than boosting the performance of low achievers?