Attitudes on police reform: Evidence from the Cooperative Election Survey

Last registered on January 03, 2023


Trial Information

General Information

Attitudes on police reform: Evidence from the Cooperative Election Survey
Initial registration date
December 21, 2022

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
January 03, 2023, 5:04 PM EST

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



Primary Investigator

IIES, Stockholm University

Other Primary Investigator(s)

PI Affiliation
University of Oklahoma
PI Affiliation
Saint Louis University

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
We conducted four experiments on voter views within the 2022 Cooperative Election Study. All four experiments related to information provision, and respondents' views on police reform, support for various bills and reforms, partisan vote choice, views on parties' reform agendas, etc.

Note that the survey has already been conducted (via YouGov and the Cooperative Election Study team) at the time that we are submitting this pre-analysis plan, but we have not been provided any information, data, or results from the survey.

Registration Citation

Downey, Mitch, John Kuk and Matthew Nanes. 2023. "Attitudes on police reform: Evidence from the Cooperative Election Survey." AEA RCT Registry. January 03.
Experimental Details


The Cooperative Election Study is the largest and most well-respected political survey in the United States. It is operated by a team at Harvard University ( and implemented by YouGov. Research teams can purchase a module including 15 minutes of questions chosen by the researcher, and administered among a random sample of 1,000 CES respondents. Our module includes four distinct information experiments (cross-randomized), and a wide range of questions to be analyzed as outcomes. All experiments will be analyzed with careful attention to differences by baseline political attitudes (observable in the rich set of "common content" questions asked by CES prior to our experimental module).

Experiment 1 randomizes information about the current set of policing policies in place across 50 large police departments. Experiment 2 randomizes information about what fraction of voters (and separately by party) are concerned about police departments' accountability for misconduct. Experiment 3 randomizes information about Member of Congress Val Demings and the police reform bill that she proposed. Experiment 4 randomizes information to highlight the salience of state and local elections for police reform.

Please see attached "Final Pre-Analysis Plan" for further details.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
See attached "Final Pre-Analysis Plan" for details.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Four experiments are cross-randomized. See attached "Final Pre-Analysis Plan" for details.
Experimental Design Details
Randomization Method
Randomization done by YouGov during implementation of survey.
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Sample size: planned number of observations
Sample size (or number of clusters) by treatment arms
See attached "Final Pre-Analysis Plan" for details.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Saint Louis University Institutional Review Board
IRB Approval Date
IRB Approval Number
IRB Name
University of Oklahoma Institutional Review Board for the Protection of Human Subjects
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents

Final Pre-Analysis Plan

MD5: c1e969c679c94aa94ce5f32b51a5d8fa

SHA1: bd54735aedcb0bb34546e24ceb4706f6b09f6a0d

Uploaded At: December 21, 2022


Post Trial Information

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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