From the comments - Marginal REVOLUTION

I am a high school teacher. As this study finds, banning phones hurts our best students. Unlike Tyler, I do have a problem with these policies. Studies like this dont even measure the ways that phones help our best students the most: they allow students to access real teachers, better teachers, sources of knowledge and learning that are beyond what they are stuck with in our public schools. There are many actions we could take that would boost grades. We could adopt singapore’s culture or the Japanese juku system. We could become as draconian as you like to boost grades for low-performing students. But to what end? Maybe there is one Peter Scholze who could boost his early learning by 5 pct, even 100 or more pct depending on what schhol he is in, with a phone. Is banning it from him worth boosting the algebra 1 scores of 20,000 future real estate salesman by 3 percent? Phones are new. Teachers have no idea how to use them. They are devices that contain the entire world’s knowledge and kids want to use them – and we are banning them? Any teacher who wants to ban phones is taking the easy way out.

That is from Frank. A broader but related point is that a school without smartphones probably cannot teach its students AI — one of the most useful things for a person to learn nowadays. As Frank indicates, you should be very suspicious that the smart phone banners take absolutely no interest in measuring their possible benefits. We economists call it cost-benefit analysis. If you wish to argue the costs are higher than the benefits, fine, that can be debated. If you are not trying to measure the benefits, I say you are not trying to do science or to approach the problem objectively.

And from a later post, again Frank:

I am a high school teacher. Tyler is right to be skeptical of phone bans. “Most likely smartphone bans in schools have some modest benefits, and still unknown costs” is accurate except that we know many of the costs.

Maybe 1-5% of the student population has no one to talk to during the school day. Their phone is their only way to reach a friend. And people want to take away that lifeline? That’s cruel.

It is also obvious that the top 1-5% of students will use their phones to learn material beyond the ability of their teachers to teach. If you haven’t been in a US public school lately, teachers are dumb. Many of them are so dumb and so convinced of the fact that they are not dumb and, indeed, intelligence is just a false construct used to oppress, that they are unaware of the vast gulf that our best students have between actual and potential achievement. They have no idea how much they have failed. Phones get around that, to an extent.

Phones have also been used to mitigate or outright avert emergencies in school.

It’s hard to see the modest benefits to lower-achieving students (who won’t use algebra anyway) outweighing the benefits.

asdf wrote:

As an academically successful student in a pretty well ranked high school my recollection was that the entire experience was horrible and torturous and essentially felt like being locked up in prison. The pace of teaching was also so slow that the marginal value add of being in class was essentially 0 when compared to the textbook reading I would do after school anyway.

So… yes it was nice to have a phone and I don’t care if it distracts stupid students from learning.