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Motivated Skepticism

Last registered on February 04, 2022


Trial Information

General Information

Motivated vs. Skeptical Beliefs
Initial registration date
April 14, 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
April 15, 2021, 6:20 AM EDT

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

Last updated
February 04, 2022, 11:02 AM EST

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



Primary Investigator

CNRS - Sciences Po

Other Primary Investigator(s)

PI Affiliation
CNRS - Sciences Po

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 study investigates a new, psychological, explanation for the fact that the unraveling of information fails in many markets contrary to what standard theory predicts (Milgrom, 1981). In particular, we ask whether it may be that agents are able to interpret skeptically the lack of evidence, but may not want to do so when the unraveling process leads to undesirable truth. To study whether having preferences over belief can explain failure of unraveling, we use a laboratory experiment in the context of a Sender-Receiver game. In a "neutral treatment", we will see if the Receiver is able to undo the Sender's communication strategy to discover the truth as predicted by economic theory. In a "loaded treatment", we will see if this reasoning is made harder by the fact that the information disclosed is about the Receiver's own performance in an IQ-test. We also manipulate exogenously how the lack of evidence should be theoretically interpreted by the Receiver or, said differently, whether being skeptical is psychologically detrimental or beneficial for the Receiver. The resulting dataset will allow us to investigate whether agents are be cognitively able but psychologically reluctant to interpret skeptically the lack of evidence.
External Link(s)

Registration Citation

Hagenbach, Jeanne and Charlotte Saucet . 2022. "Motivated vs. Skeptical Beliefs ." AEA RCT Registry. February 04.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
The key outcome variables are the Senders' information and actions, and Receivers' decisions in each game.
Primary Outcomes (explanation)
See the attached PAP document.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We consider one of the simplest incomplete information games, namely a sender-receiver disclosure game: an informed Sender transmits hard information to an uninformed Receiver, who acts upon this information. We exogenously vary wether the information that the Sender communicates about is neutral or loaded, in that it corresponds either to a number with no particular meaning or to the Receiver's performance. In the latter case, the Receiver may have intrinsic preferences for believing he performed well, which potentially affects the way he reads strategically-disclosed information. By playing on the Sender's incentives, we also vary whether vague or absent disclosure should, in theory, be interpreted by the Receiver as a high or low performance.
Experimental Design Details
See the attached PAP document.
Randomization Method
We randomly assign each experimental session to one of the 4 treatments. Subjects voluntary sign up to participate in our online sessions but, at the time of registration, cannot know the treatment they will receive.
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
No clustering.
Sample size: planned number of observations
320 subjects.
Sample size (or number of clusters) by treatment arms
80 subjects per treatment.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
Research Ethics Committee of the Paris Institute of Political Studies
IRB Approval Date
IRB Approval Number
Analysis Plan

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Post Trial Information

Study Withdrawal

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Is the intervention completed?
Intervention Completion Date
June 29, 2023, 12:00 +00:00
Data Collection Complete
Data Collection Completion Date
June 29, 2023, 12:00 +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
2000 Sender-Receiver games in the Main Experiment; 640 Sender-Receiver games in the Complementary Experiments
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
2640 games
Final Sample Size (or Number of Clusters) by Treatment Arms
540 games in the High_Neutral treatment; 480 games in the High_Loaded treatment; 500 games in the Low_Neutral treatment; 480 games in the Low_Loaded treatment; 300 games in the Low_Loaded_FixedPayIQ treatment 340 games in the Low_Neutral_ModifiedPriors treatment
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials