At least 37 states, as well as Washington D.C., have banned phones and other electronic devices. It costs a hefty amount to do so. New York City public schools have allocated $29 million on phone pouches to hold devices during the day. Los Angeles schools spent $5.2 million. Other major metros are throwing hundreds of thousands of dollars to take phones out of the classroom.

And while that push gains steam, researchers at Stanford University, Duke University, the University of Michigan, and the University of Pennsylvania just conducted the most comprehensive study of phone bans since schools started enforcing them, and the results are mixed. 

The study, a working paper published in the National Bureau of Economic Research (NBER), found that out of data from 4,600 schools, bans have produced  virtually no net change to test scores. They’ve also not moved the needle on bullying, classroom attendance, and self-reported attention rates, many of the conditions the bans were meant to improve. 

“We do see slightly positive effects in high schools, and slightly even smaller effects, and negative in middle schools,” Duke professor and study co-author E. Jason Baron, told Fortune, speaking of the impact on test scores. “But again they’re basically close to zero, both of them.”

Meanwhile, high schoolers’ math and reading scores have continued plummeting, reaching historic lows in 2024 even as phone bans have grown in popularity. 

Computer use in schools may be hurting student test scores

Of course, there are other factors that may contribute to this decline. While phones have disappeared from the classroom, other devices have moved in. 

Computers are now a staple of the American educational experience; most students are handed one to complete assessments and homework. But recent research shows the tech may be doing more harm than good. 

Jared Cooney Horvath, a neuroscientist and former teacher, recently testified in front of Congress on the harms of computers in the classroom, citing data from the Program for International Student Assessment  that showed a correlation between a dip in test scores and increased computer use among 15-year-olds globally.

“Before 2014, computers were in schools, they were just peripheral,” Horvath, a neuroscientist, told Fortune in a recent interview. “After 2014, every school had to have digital infrastructure in order to take the state assessment.”

Kids are staying off the phone. But test scores remain elusive

But the NBER study found that student wellness is improving. While well-being worsens in the first year of the ban, the results are positive by the third year. There’s a short-term uptick in phone-related disciplinary incidents, but they fall back down soon after. 

Teachers are also satisfied as bans take away the arduous task of incessantly asking students to put their phones away. That’s another outcome that Yondr, the company that makes phone pouches schools use, has applauded.

“It reinforces what school leaders have been telling us for years: a phone-free school lays the foundation for calmer, more focused classrooms, where teachers feel supported and students have the space to develop the social skills needed in today’s world,” Yondr CEO Graham Dugoni said in a statement.

Jonathan Haidt, author of The Anxious Generation, a book that examines the impact of phone use on youth mental health, weighed in on the study in a post on X. 

The social psychologist, who is a leading figure in the push to get phones banned from the classroom, highlighted the fact that phone bans are still offering more opportunities for face-to-face interaction. 

“Phone-free schools seem to be producing more social interaction in class, and a lot more noise and laughter in the hallways, and at lunch,” he said. 

Still, the results are disappointing for anyone expecting an improvement in test scores. The findings are even more stark when compared to a similar study conducted in 2013 on the relationship between phone bans and test scores in the U.K. There, test scores improved 6.4% after phone bans were implemented, with the biggest gains observed among low-achieving students.

Baron said that while phone bans offer a host of benefits, policymakers ought to understand they’re not a panacea for a school’s issues.

“If you’re a school and you really care about getting kids off their phones, this seems to work very well,” he said. “If you really care about test scores, then what our study can tell you is that, up to three years after you’re not seeing much.”