Preempting Polarization: An Experiment on Opinion Formation (Democrats)

Last registered on May 24, 2023


Trial Information

General Information

Preempting Polarization: An Experiment on Opinion Formation (Democrats)
Initial registration date
May 23, 2023

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
May 24, 2023, 4:55 PM EDT

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



Primary Investigator

University of Warwick

Other Primary Investigator(s)

PI Affiliation
The University of Chicago

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
This is an experimental study on public policy opinion formation with a sample of Democrats. We have previously pre-registered and conducted a simiar study with a sample of Republicans (AEARCTR-0009704).
External Link(s)

Registration Citation

Kashner, Dan and Mateusz Stalinski. 2023. "Preempting Polarization: An Experiment on Opinion Formation (Democrats)." AEA RCT Registry. May 24.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Amount donated (out of $0.5 bonus payment) to the Electronic Frontier Foundation, a charity that supports net neutrality
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
The side of the argument (pro vs. con) that the participant chooses when evaluating non-partisan information from two videos
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experimental design is hidden until the end of the trial.
Experimental Design Details
We recruit participants on Prolific. We restrict the pool of eligible participants to those who answered "Democrat" on Prolific's US political affiliation question and those who answered the question about their 2020 vote (regardless of the answer). Participants are required to complete a 15-minute Qualtrics survey about net neutrality.

After collecting demographics and a brief introduction to the issue of net neutrality, we randomize participants into two treatment groups: BEFORE and AFTER.

Participants in the AFTER group will see the PRO and CON videos on net neutrality immediately after we introduce the issue. After both videos play, participants are shown the "PRO vs CON question". At the bottom of the page (so they can re-watch any videos, as needed) they are asked to explain (in at least 20 words) which argument they found most convincing, pro or con. To incentivize engagement, they are told the top 25% of answers (based only on the clarity of their answer, not which side they chose) will receive a bonus payment. On the following page, they indicate whether the most convincing argument was from the PRO video (in favor of net neutrality) or the CON video (against net neutrality).

Participants in the BEFORE group watch the PRO and CON videos after learning that the Republican party opposes the issue of net neutrality and the Democratic party supports the issue. When they watch the video content, they can interpret it with this knowledge from Partisan Information in mind. When they answer the "PRO vs CON question", they have knowledge of both Partisan Information and Non-partisan Information.

In both treatment groups, after participants have received both Partisan and Nonpartisan Information, they are told that they now have a chance to support net neutrality. They are told about the Electronic Frontier Foundation, a charity that supports net neutrality. They are offered a $.50 bonus payment, and they are asked how much of that bonus they would like to donate to the net neutrality charity, EFF.

Both for the primary and the secondary outcome, to test for the impact of the intervention on the outcome, we will use a two-sided t-test for difference in means between the two experimental conditions (BEFORE and AFTER).
Randomization Method
Qualtrics randomization
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
800 individuals
Sample size (or number of clusters) by treatment arms
400 individuals per group
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Social and Behavioral Sciences Institutional Review Board The University of Chicago
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials