[pavel_lishin]

> There were no statistically significant changes in test scores during the first year of the ban, when disciplinary rates were high. During the second year of the ban, in contrast, test scores increased significantly, with positive effects concentrated during the spring semester (scores increased 1.1 percentiles, on average). The researchers suggest that this may be due to the higher stakes of spring tests, which can affect grade advancement and high school graduation. Test score improvements were also concentrated among male students (up 1.4 percentiles, on average) and among middle and high school students (up 1.3 percentiles, on average).

> When comparing high-effect and low-effect schools, the researchers note significant reductions in unexcused absences during the two years following the cell phone ban. They posit that increased attendance could explain as much as half of the test score improvements noted in their primary analysis.

Seems to me like there wasn't a huge improvement, and the improvement seen could easily be attributed to other things, no?