Smartphone bans and students’ wellbeing: Experimental evidence from high schools in Peru

Last registered on October 06, 2025
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Pre-Trial

Trial Information

General Information

Title
Smartphone bans and students’ wellbeing: Experimental evidence from high schools in Peru
RCT ID
AEARCTR-0016895
Initial registration date
October 02, 2025

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
October 06, 2025, 11:42 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Country
Peru
Region
Lima

Primary Investigator

Name
Elena Arias Ortiz
Affiliation
Inter-American development Bank
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Other Primary Investigator(s)

PI Name
Samuel Berlinski
PI Affiliation
Inter-American Development Bank
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PI Name
Julian Cristia
PI Affiliation
Inter-American Development Bank
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PI Name
Emma Naslund-Hadley
PI Affiliation
Inter-American Development Bank
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PI Name
Sonia Suarez
PI Affiliation
Inter-American Development Bank
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Additional Trial Information

Status
On going
Start date
2025-08-13
End date
2025-12-19
Keywords
Education
Additional Keywords
Smartphones, Wellbeing, Secondary Schools, Peru
JEL code(s)
I21 – Analysis of Education: Education and Economic Development I28 – Education: Government Policy I31 – General Welfare, Well-Being
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
We conduct an experimental evaluation to examine the effects of restricting mobile phone use in schools on the socioemotional well-being of public secondary students in Lima, Peru. The randomized controlled trial includes 104 schools that are randomly assigned to one of two arms: a treatment group that introduces locking pouches to restrict phone use during school hours, accompanied by an awareness campaign for students, teachers, and parents about the risks of excessive use; and a control group. The intervention is implemented school-wide: all students who report bringing a cellphone to school are provided with a pouch in which they must store their phone during school hours. We collected baseline data on cellphone ownership and on whether students bring their phones to school to students in grades 3 to 5. We also collected data from all students in a randomly selected third-grade section on a range of dimensions such as demographics, cellphone ownership and use, socioemotional well-being (WHO-5), mental health (PHQ-4), behavior (SDQ), attitudes toward cellphone restrictions, school climate, peer relationships, and sleep patterns. Implementation started in September 2025 and will continue at least until November 2025 (and later if funding is secured). The study will collect endline measures to estimate impacts on emotional wellbeing, mobile-use patterns and potential mechanisms such as interpersonal relations complemented by administrative records on academic performance.
External Link(s)

Registration Citation

Citation
Arias Ortiz, Elena et al. 2025. "Smartphone bans and students’ wellbeing: Experimental evidence from high schools in Peru." AEA RCT Registry. October 06. https://doi.org/10.1257/rct.16895-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Treatment package (school-wide): Restrict in-school mobile phone use by providing locking pouches for students during school hours, plus an awareness campaign for students, teachers, and parents on the risks of excessive phone use. The intervention is implemented at the school level.

Control condition: Business as usual.

Timing & dose: Rollout over three months during the 2025 school year. Baseline surveys are conducted immediately prior to implementation; endline after the 3-month exposure. We plan to continue the intervention during 2026 and later if funding is secured.

To strengthen the study’s internal validity, we will implement multiple quality-control strategies, including instrument standardization and validation, rigorous enumerator training, continuous fieldwork supervision, and verification of implementation fidelity
Intervention (Hidden)
Intervention Start Date
2025-09-11
Intervention End Date
2025-12-19

Primary Outcomes

Primary Outcomes (end points)
Components measured at endline for surveyed students who participated in the baseline:
1. SDQ Internalizing problems (scale, reverse-coded so higher = better)
2. SDQ Externalizing problems (scale, reverse-coded so higher = better)
3. WHO-5 Psychological well-being (scale)
4. PHQ-4 Anxiety/Depression (scale, reverse-coded so higher = better)
5. Life satisfaction (single item, 0-10).
Each component will be standardized (z-score using the mean and SD of the control group) and oriented so higher = better. The primary outcome is an equal-weighted index averaging the standardized components available at endline (and re-standardized to produced a z-score using the mean and SD of the control group). This primary outcome will not be adjusted for multiple hypothesis testing. We will produce these adjustments for the five individual indices.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Educational outcomes (constructed using administrative data):
1. Grades (average standardized z-scores using grades at the grade level)
2. Repetition (binary, 1 = repeated the year)
3. Dropout (binary, 1 = not enrolled at endline)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We implement a cluster randomized controlled trial at the school level to estimate the causal effect of restricting in-school mobile phone use on student outcomes. From an eligible sample of 104 public secondary schools in Lima, 52 schools were randomly assigned to the treatment group and 52 to the control group. Group description:
 Treatment: locking pouches for cellphones during school hours plus an awareness campaign for students, teachers, and parents;
 Control: business as usual (no intervention).
Randomization occurred after baseline data was collected. It was blocked by school enrollment size: schools are first ordered by the number of enrolled students and then grouped into blocks of equal size (four schools per block). Within each block, half of the schools are randomly assigned to the treatment group and half to the control group. The unit of randomization is the school, while the primary unit of analysis is the student. Our main results will include ITT estimates but we will also report ToT estimates considering effects on actual in-school phone use. We will cluster the standard errors at the school level and include dummies in regressions for randomization blocks and baseline outcomes (when available).
Experimental Design Details
Randomization Method
Randomization was done using Stata
Randomization Unit
School Level
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
104 secondary schools in Lima
Sample size: planned number of observations
13,800 students in grades 3 to 5 (Parameters. Mean enrollment 260. Students in grades 3 to 5: 60%; Attendance to endline: 85%)
Sample size (or number of clusters) by treatment arms
52 control group; 52 treatment group
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Econometria Consultores
IRB Approval Date
2025-07-17
IRB Approval Number
008-2025
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials