Experiments on Willful Ignorance

Last registered on June 21, 2022


Trial Information

General Information

Experiments on Willful Ignorance
Initial registration date
September 15, 2021

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
September 16, 2021, 10:30 PM EDT

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

Last updated
June 21, 2022, 3:19 AM EDT

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



Primary Investigator

Paderborn University

Other Primary Investigator(s)

PI Affiliation
Paderborn University

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Many people claim to intend to act pro-socially but do not. One reason might be that they are willfully ignoring the harm that they impose on others; this may allow them to maintain a positive self-image while serving their own interests. If this is the case, careful reflection may reveal to subjects that they are "kidding" themselves. We examine experimentally, whether reflection results in more people informing themselves about the negative consequences of their choices.
External Link(s)

Registration Citation

Bopp, Fabian and Wendelin Schnedler. 2022. "Experiments on Willful Ignorance." AEA RCT Registry. June 21. https://doi.org/10.1257/rct.8172-1.1
Experimental Details


The intervention will consist of an ex-ante questionnaire, which is administered to half of the participants. In the questionnaire, the subjects will be confronted with questions with the aim to cause a better reflection of the situation.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
The variable of interest is whether subjects reveal information or not.
Primary Outcomes (explanation)
This can be directly observed in the data.

Secondary Outcomes

Secondary Outcomes (end points)
The follow-up decision in the game after revealing or not revealing information is to either make a selfish or a prosocial choice.
Secondary Outcomes (explanation)
Again, this can be directly observed in the data.

Experimental Design

Experimental Design
The design is based on the hidden information treatment in the moral wiggle room game by Dana, Weber, and Kuang (2007). Subject A can choose between two Options 'high' and 'low'. His payoff is directly connected to his choice and is known to subject A. Also, the payoff of subject B is depending on the choice of A. Here, at the beginning of the game either the interest are conflicting or aligned. If the interests are aligned the 'high' option is best for both subjects. If the interests are conflicting, the 'low' option is better for subject B and worse for A. In this case, subject A would be in a social dilemma. Subject A can decide whether he wants to learn whether the interests are aligned or conflicting. (This is the primary outcome variable.) In order to maximize observations, we use the stratetgy method for the information decision. To boost reflection, we use a questionnaire that half of the subjects in the role of A have to fill in. (This is the intervention.) In the questionnaire, A has to answer questions on his future actions in the game and thus ex-ante think through and reflect the game.
Experimental Design Details
Randomization Method
Randomization is done on individual level by a computer.
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
Depending on the show-up rate and technical procedure the number of experimental sessions may vary. We plan to conduct X-Y sessions with 24 subjects per session.
Sample size: planned number of observations
XXX subjects
Sample size (or number of clusters) by treatment arms
As one treatment arm will be a replication the size of this arm can vary on the results. If in our pool the results are on a very similar level and are not significantly different from other studies, we may pool our data with old data and focus on the non-replication treatments.
If this is not the case we will have same-sized treatment arms.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Ethik-Kommission der Universit├Ąt Paderborn
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