Here is a new paper by Sara Abrahamsson. Perhaps there is Norwegian exceptionalism at work, but the results reflect my expectations reasonably closely. The basic setting is that smart phones were banned in middle school, but at varying (and exogenous) rates around the country. Here are some of the core findings, noting that reading the paper gives some different impressions from some of the Twitter summaries:
1. Grades improve, for instance for the girls it goes up by 0.08 standard deviations. Worth doing, but hardly saving a generation. For girls, the biggest improvement comes in their math scores.
2. The girls consult less with mental health-related professionals, with visits falling by 0.22 on average to their GPs, falling by 2-3 visits to specialist care.
3. “I find no effect on students’ likelihood (extensive margin) of being diagnosed or treated by specialists or GPs for a psychological symptom and diseases.” So more visits, but those visits don’t lead to much.
4. Bullying falls, by 0.42 of an SD for girls, 0.39 of an SD for boys. That is a larger effect than I would have expected.
5. The grade gains are highest for students with lower SES backgrounds.
6. When you look into the details of the data (p.22), the improvement in grades does not seem correlated with the decline in the number of visits to mental health professionals.
So if you ban smart phones from schools, grades go up by a very modest amount, bullying falls by a less modest amount, and actual mental health diagnoses stay the same. In the United States at least, parents seem to hate cellphone bans, because they cannot reach their kids at will.
And there you go. Here is some commentary on the p values in the paper.
