U-M studies examine what schools are doing to address cell phone use among students
By Kate Barnes
As tablets and laptops have become common classroom tools, schools continue to wrestle with another device: the cell phone.
Cell phones play a critical role in youth social and societal engagement and schools are seeking information on how best to address their use during school hours. Some argue cell phones should be banned outright, while others see benefits to allowing students to access the devices throughout the school day.
Is there a middle ground? Can schools encourage attentive learning while also allowing students to have access to something so central to their daily lives?
Through separate statewide and national studies, University of Michigan researchers are working to address these and related questions to provide school communities, students and families with clear guidance.
As a parent of teenagers, Brian Jacob has seen firsthand how difficult it can be for young people to put down their phones. Whether using social media, researching something for school or texting with friends, students seemingly have endless access to content and ways to engage with others online. But during the school day, how important is it to put the phone away?
“I have heard from my own kids how distracting having cell phones in class can be,” said Jacob, the Walter H. Annenberg Professor of Education Policy at the University of Michigan Gerald R. Ford School of Public Policy. “They will be in the middle of a lesson, and the teacher has to stop and ask for the phones to be put away multiple times.”
One might think the simple answer is to ban cell phone usage during the school day.
Not so fast, Jacob notes. Despite the risk of distraction during instructional time, cell phones often give students access to important information and tools, including health data, medicine reminders and safety tip lines.
So, how can schools determine what is best for their students? What evidence shows whether restrictions work and how they impact students?
“What is really important, in both the national and state studies, is to get as much information as possible from the very diverse populations we are working with. We need to understand why certain districts are choosing certain policies and if they are having their intended effect. We also want to see how schools react to the new law — are they simply updating existing policies or adopting new ones?”
Enter Jacob and fellow U-M faculty members Justin Heinze and Elyse Thulin. Both are faculty members in the U-M Institute for Firearm Injury Prevention and Heinze is also an associate professor of health behavior and health equity in the U-M School of Public Health. Heinze’s work focuses on youth development, while Thulin studies how technology can exacerbate — or be used to reduce — the risk of harm.
Together, the trio of researchers and their teams are examining not only how students are using phones during the school day, but also what restrictions schools place on the devices and how those policies affect students and staff.
“Before this study, I would have said ‘get rid of them’, in terms of cell phones in school,” Heinze said. “But after starting this project with Brian and his team at the Youth Policy Lab, we know now it is more about finding ways to use the cell phones as productive tools and lessening interruptions rather than removing them completely.”
Jacob serves as co-director of the Youth Policy Lab, a joint research center of the Ford School and the U-M Institute for Social Research. Jacob, Heinze and Thulin are conducting a Michigan study of cell phone use and school restrictions, while Jacob is also leading a national study on the topic.
In Michigan, a law enacted in fall 2025 requires school districts to adopt policies limiting student cell phone use, with exceptions for emergencies and academic purposes. The researchers note the law’s implementation will vary across school districts, citing the differences in school communities, funding priorities, constituencies and locations.
“What might work for one school might not work for another,” Thulin said. “So we are really interested in finding out more about how students use their cell phones during school hours and how that can help inform the restrictions.”
Existing research shows policies differ in when restrictions apply, how phones are stored, such as in lockers or lockable pouches, and who enforces the rules, whether teachers or school administrators.
“Before this study, I would have said ‘get rid of them ’ in terms of cell phones in school. But after starting this project with Brian and his team at the Youth Policy Lab, we know now it is more about finding ways to use the cell phones as productive tools and lessening interruptions rather than removing them completely.”
These approaches can affect students and staff in different ways, which the team also plans to examine. The Michigan study will gather input from students, school leaders, teachers and parents to consider a range of concerns and perspectives.
“We know from research that students often use their phones for, let’s say, medication reminders, other health notifications or technology-facilitated reporting systems,” Thulin said. “Their phones can help them feel safe and linked to their support systems, which is important to consider when deciding which restrictions to put into place.”
For the national study, Jacob is working with researchers from Duke University, Stanford University and the University of Pennsylvania to survey how schools in different states are navigating this modern-day challenge.
One question, two studies
Brian Jacob, the Walter H. Annenberg Professor of Education Policy at the Ford School of Public Policy and co-director of the Youth Policy Lab, is a lead researcher on bot
| The national study | The Michigan study | |
| ASKS | What happens when schools lock phones in pouches | Which phone rules do districts choose, and how do they affect students? |
| WHERE | Thousands of U.S. public schools that adopted pouches, compared with similar schools that didn't | Nearly every publicly funded district in Michigan, before and after the state law |
| WHO | Jacob with colleagues at Stanford, Duke and Penn | Jacob, Justin Heinze and Elyse Thulin, with the Michigan Department of Education and state partners |
| STATUS | Three-year study. Peer reviewd and accepted for publication in the Quarterly Journal of Economics, forthcoming | Three-year study, runs through 2028 |
| FOUND SO FAR | Phone use fell, teachers were more satisfied, a rough first year that faded, little change in test scores | Districts' written rules vary widely. In 62% of districts, stuents keep phones on them, out of sight |
Sources: Allcott, Baron, Dee, Duckworth, Gentzkow and Jacob, forthcoming in the Quarterly Journal of Economics (NBER Working Paper 35132); Michigan School Cellphone Policy Study Landscape Analysis, May 2026.
“What is really important, in both the national and state studies, is to get as much information as possible from the very diverse populations we are working with,” Jacob said. “We need to understand why certain districts are choosing certain policies and if they are having their intended effect. We also want to see how schools react to the new law — are they simply updating existing policies or adopting new ones?”
The researchers say a multidisciplinary team is essential to studying the issue.
“We all have a different focus, but that is really important in something like this,” Jacob said. “By bringing together people with adjacent research interests we can think about challenges in really innovative ways, and that is what we hope to do.”
The team hopes the two studies work in tandem to inform policymakers considering statewide requirements and school leaders evaluating district policies. By developing an evidence base, Jacob, Heinze and Thulin aim to share rigorous data, promising practices and resources that school communities can use to help students thrive.
“We really are looking at all outcomes of these policies and restrictions,” Heinze said. “Are they reducing school violence? Are they improving student mental health? Are we seeing students more engaged in learning? What behaviors have changed? Are teachers happier? These are all questions we are asking and hope to help answer.”
Federal and foundation grants support both studies.
“We know from research that students often use their phones for, let’s say, medication reminders, other health notifications or technology-facilitated reporting systems. Their phones can help them feel safe and linked to their support systems, which is important to consider when deciding which restrictions to put into place.”
What happened when U.S. schools locked phones in pouches
Researchers including U-M’s Brian Jacob compared public schools that adopted lockable phone pouches with similar schools that did not.
Phone activity fell
-30%
GPS-measured device activity on school campuses during school hours was about 30% lower by the third year, based on aggregated, anonymous GPS data that serve as a proxy for phone activity rather than a direct count of student use.
Aggregated, anonymous GPS data. A proxy for phone activity, not a direct count of student use.
Teacher satisfaction
+49 pts
Teachers reported much greater satisfaction with their school’s phone policy after pouches were adopted.
26% before → 75% after
Descriptive teacher survey result.
A rough first year, then a recovery
YEAR 1
Disciplinary incidents ↑
Student well-being ↓
YEAR 2
Discipline effects faded
Student well-being ↑
The early disruption faded. In later years, well-being estimates became positive.
The well-being pattern is suggestive and should be interpreted cautiously.
Little or no change
- Test scores
- Attendace
- Online bullying
- Classroom attention
Average test-score effects were close to zero. High schools saw small gains; middle schools saw small declines
HOW THEY KNOW
Researchers used pouch-maker sales records to identify thousands of U.S. public schools that adopted pouches, then compared them with similar schools before and after adoption. Data came from aggregated anonymous GPS activity, a national teacher survey, test scores and school records.
HOW SETTLED THIS IS
The study has been peer reviewed and accepted for publication in the Quarterly Journal of Economics, where it is forthcoming. The authors describe it as a first step, and pouches are one of several ways schools restrict phones.
Source: Allcott, Baron, Dee, Duckworth, Gentzkow and Jacob, NBER Working Paper 35132.