The Dark Side of Digital -- Evidence from a Field Experiment

Last registered on February 25, 2025
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Pre-Trial

Trial Information

General Information

Title
The Dark Side of Digital -- Evidence from a Field Experiment
RCT ID
AEARCTR-0013182
Initial registration date
February 24, 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
February 25, 2025, 10:52 AM EST

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

Locations

Country
Belgium
Region
Country
Germany
Region
Country
France
Region
Country
Italy
Region
Country
Sweden
Region

Primary Investigator

Name
Lorenzo Pinna
Affiliation
Università Degli Studi di Siena
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Other Primary Investigator(s)

PI Name
Andrea Blasco
PI Affiliation
European Commission
Contact Investigator

Additional Trial Information

Status
In development
Start date
2025-02-25
End date
2025-05-15
Keywords
Behavior, Education
Additional Keywords
Behavioural Economics, Misperceptions, Social norms, Digital addiction, Smartphones, Social Media
JEL code(s)
C21, C83, C90, D12, D83, D91
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
We examine the impact of a social-norm intervention on healthy smartphone use and student well-being. We will recruit 12,000 students aged 18 and 30 across five European countries. Participants will be randomly assigned to a social-norm intervention, where they compare their smartphone use to their peers' median, or a self-reflection control that provides no comparison with peers. We will collect several measures on students' well-being and smartphone habits, including objective screen time statistics. Additionally, we will assess the effectiveness of a "nudge" intervention, where students receive tips for healthier smartphone use: setting time limits, a digital detox, keeping the phone outside the bedroom at night, or a control condition (no tips). This study builds on prior experimental research testing the effectiveness of social-norm interventions in various fields, extending their application to correcting misperceptions about smartphone use. Our findings will contribute to the literature on digital addiction and the risks of excessive use of social media, highlighting the role of social-norm misperceptions and informing the design of public policies to mitigate excessive social media consumption.
External Link(s)
EU page of the project.

Registration Citation

Citation
Blasco , Andrea and Lorenzo Pinna . 2025. "The Dark Side of Digital -- Evidence from a Field Experiment." AEA RCT Registry. February 25. https://doi.org/10.1257/rct.13182-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
The experiment will consist of two primary interventions: (1) a social norm intervention and (2) a nudge intervention to reduce students' screen time. A third ancillary intervention will consist of (3) making mandatory vs voluntary screenshot uploads of Screen Time statistics. This treatment is intended to ensure the accuracy of the data on students' screen time while, at the same time, reducing the burden on students completing the survey, minimising the risk of attrition.
Intervention Start Date
2025-03-25
Intervention End Date
2025-04-15

Primary Outcomes

Primary Outcomes (end points)
Before the follow-up:

1. self-reported ideal screen time

After the follow-up:

2. life satisfaction, happiness and loneliness scale (from the European Social Survey)
3. fear of missing out scale [@przybylski2013fear, 10 items]
4. smartphone addiction scale [@lopez2017short, 10 items]
5. active vs passive social media consumption scale
6. academic performance
7. change in screen time as measured by the phone's Screen Time statistics
Primary Outcomes (explanation)
Before the follow-up:

1. self-reported ideal screen time

After the follow-up:

2. life satisfaction, happiness and loneliness scale (from the European Social Survey)
3. fear of missing out scale [@przybylski2013fear, 10 items]
4. smartphone addiction scale [@lopez2017short, 10 items]
5. active vs passive social media consumption scale
6. academic performance
7. change in screen time as measured by the phone's Screen Time statistics

In the follow-up survey, we will also measure whether the respondents followed the tip they received in the nudge intervention, if at all, and the perceived effectiveness of the tip.

Secondary Outcomes

Secondary Outcomes (end points)
The secondary outcome variables are individual attitudes towards smartphones overall and social media in particular, including attitudes towards different forms of regulation and whether social media companies are transparent and/or responsible for regulation. The variables are:

1. Perceived negative vs positive impact of social media on students
2. Perceived smartphone "make life better or worse"
3. Concerns about digital addiction risks for students of their age
4. Perceived transparency of social media companies
5. Whether the government should regulate smartphone use and what interventions.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The sample will be divided into eight treatment groups corresponding to all possible combinations for 2 (social norms) x 4 (nudges) treatments. The randomisation will be done at the individual level -- each student will be randomly assigned to one of the eight treatment cells. To ensure a balanced treatment assignment, we will use a stratified randomisation by country, gender, and age. Independently, about half of the students will be also randomly assigned to the mandatory vs non-mandatory screenshot upload group.
Experimental Design Details
Not available
Randomization Method
Randomisation will be prepared on a computer and saved on a spreadsheet file. The random assignment will be clustered by country, age, education, and gender and shared with the panel provider for implementation.
Randomization Unit
Individual students who participate in the survey.
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
The random assignment is clustered by country, age, gender, and education.
Sample size: planned number of observations
12,000 students from the first survey.
Sample size (or number of clusters) by treatment arms
(12/8) ± 1500 per treatment arm;
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
JRC Ethical Review Board
IRB Approval Date
2024-04-09
IRB Approval Number
JRC project id: 32530
Analysis Plan

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