Strategic Ignorance in the Presence of Bystanders

Last registered on March 26, 2026

Pre-Trial

Trial Information

General Information

Title
Strategic Ignorance in the Presence of Bystanders
RCT ID
AEARCTR-0009283
Initial registration date
April 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
April 28, 2022, 5:46 PM EDT

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

Last updated
March 26, 2026, 3:56 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Region

Primary Investigator

Affiliation
University of Oslo

Other Primary Investigator(s)

Additional Trial Information

Status
Completed
Start date
2022-04-21
End date
2023-01-01
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
A growing body of research, pioneered by Dana et al. (2007), has confirmed the prevalence of strategic ignorance: if acting in one’s own interest might harm the interest of someone else, many individuals prefer not to know whether interests conflict or align; moreover, if given the option to stay ignorant, subjects tend to behave more selfishly. In particular, Dana et al. (2007) found that in a binary version of the dictator game, only 26% of subjects chose the selfish alternative when payoffs were known. However, when dictators had to click a button to reveal whether there was a conflict of interest between themselves and the recipient, many abstained from revealing this information, and as much as 63% of those who actually faced conflicting interest now chose the selfish option.
Although willful ignorance may be caused by confusion or lack of interest, individuals may also avoid information in order to keep a good self-image or social image while behaving selfishly. If an individual – below, the dictator – stays ignorant for such self-image reasons, however, and someone else imposes the avoided information on them anyway, this could trigger negative social reactions. Also, if the dictator knows that a bystander is likely to impose the information, this may deter the dictator from choosing ignorance in the first place. The present project aims to explore, in a context of strategic ignorance, the interplay between dictators and bystanders who may choose to impose information on the dictator.
Our first question is whether the presence of a bystander affects the share of selfish choices by dictators. If so, is this caused by the mere presence of the bystander – through giving the dictator a feeling of being watched, for example – or is it caused by the bystander’s actual provision of information?
If the dictator would really have preferred to stay ignorant, i.e., the information is in fact unwelcome, a bystander choosing to provide information might trigger negative emotions on the dictator’s part. Our second question is thus whether bystanders’ provision of information is deterred when the dictator has an option to sanction the bystander.
Third, what determines whether dictators use the option (if available) to sanction bystanders? Are sanctions mainly used by dictators who prefer to stay ignorant? If so, do they mainly sanction bystanders who provide information? If the bystander provides information, does it matter whether the news is good (aligned interests) or bad (conflicting interests)?
Fourth, does the knowledge that a bystander is present reduce dictators’ propensity to stay ignorant, as in the study by Lind et al. (2019)?
External Link(s)

Registration Citation

Citation
Nyborg, Karine. 2026. "Strategic Ignorance in the Presence of Bystanders ." AEA RCT Registry. March 26. https://doi.org/10.1257/rct.9283-2.0
Experimental Details

Interventions

Intervention(s)
Please see the preplan text.
Intervention (Hidden)
Intervention Start Date
2022-04-21
Intervention End Date
2023-01-01

Primary Outcomes

Primary Outcomes (end points)
Dictators' choice of ignorance versus information; selfish versus unselfish option; sanctioning versus no sanctioning. Bystander's choice of information provision. Please see the preplan text for details.
Primary Outcomes (explanation)
Please see the preplan text for details.

Secondary Outcomes

Secondary Outcomes (end points)
Please see the preplan text for details.
Secondary Outcomes (explanation)
Please see the preplan text for details.

Experimental Design

Experimental Design
Please see the preplan text for details
Experimental Design Details
Randomization Method
Randomization by computer
Randomization Unit
Individuals, online experimental sessions.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
At least 100 participants for each treatment
Sample size: planned number of observations
At least 100 participants for each treatment
Sample size (or number of clusters) by treatment arms
At least 100 participants for each treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
UC Merced Institutional Review Board,
IRB Approval Date
2021-04-21
IRB Approval Number
UCM2021-42
Analysis Plan

Analysis Plan Documents

Strategic Ignorance in the Presence of Bystanders

MD5: 79ed9266e1d7aaf61e920b88ea5990d7

SHA1: 4468ae941e353a0a4489196ca2754257fd44bc10

Uploaded At: April 20, 2022

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
Yes
Intervention Completion Date
July 15, 2022, 12:00 AM +00:00
Data Collection Complete
Yes
Data Collection Completion Date
July 15, 2022, 12:00 AM +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
232 subjects
Final Sample Size (or Number of Clusters) by Treatment Arms
116 pairs (55 in Baseline, 61 in Hidden Information). This was a failed replication attempt. New replication attempt (successful), followed by main study, was preregistered at https://www.socialscienceregistry.org/trials/11289. The present study is thus only reported in the appendix of the resulting paper.
Data Publication

Data Publication

Is public data available?
Yes

Program Files

Program Files
No
Reports, Papers & Other Materials

Relevant Paper(s)

Abstract
Since ignorance can serve as an excuse for selfish behavior, people sometimes avoid learning about possible negative externalities of their actions. In social situations, however, others might provide the information anyway. How do potential informers affect willful ignorance and the resulting social outcomes? We introduce a third-party potential informer into the moral wiggle-room game. Almost half of the dictators avoided information only to have it imposed upon them by the informer. Most of these unwillingly-informed dictators revised their behavior to benefit the recipient, even at a cost to themselves. While knowledge of the informer’s presence did not change dictators’ propensity to seek information, a subtle change in the experimental choice interface did: The share of dictators choosing ignorance was more than halved when dictator’s ignorance and allocation choices were made in two separate decision screens rather than a single one.
Citation
Grossman, Z., T. Hua, J.T. Lind, K. Nyborg (2026): Unwillingly informed: the prosocial impact of third-party informers, Journal of Environmental Economics and Management (in press), https://doi.org/10.1016/j.jeem.2026.103330.

Reports & Other Materials