The Role of Memory in Beliefs Formation

Last registered on August 01, 2020


Trial Information

General Information

The Role of Memory in Beliefs Formation
Initial registration date
August 09, 2019

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
August 09, 2019, 9:48 AM EDT

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

Last updated
August 01, 2020, 5:42 AM EDT

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



Primary Investigator


Other Primary Investigator(s)

PI Affiliation
Microsoft Research and NBER
PI Affiliation
University of Michigan

Additional Trial Information

Start date
End date
Secondary IDs
This experiment studies how people memory limitations affect the process of beliefs formations.
External Link(s)

Registration Citation

Mobius, Markus, Tanya Rosenblat and Pierre-Luc Vautrey. 2020. "The Role of Memory in Beliefs Formation." AEA RCT Registry. August 01.
Former Citation
Mobius, Markus, Tanya Rosenblat and Pierre-Luc Vautrey. 2020. "The Role of Memory in Beliefs Formation." AEA RCT Registry. August 01.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Double counting. Effect of time decay (through distraction) on double counting.
Primary Outcomes (explanation)
The outcomes are constructed using logit belief updates regressions which are described formally in the PDF attached.

Secondary Outcomes

Secondary Outcomes (end points)
Can double counting be explained only by limited attention and imperfect recognition?
Secondary Outcomes (explanation)
This is based on theoretical bounds on double counting that we derive in the attached PDF.

Experimental Design

Experimental Design
The experiment consists in having participant read fictional news about a fictional company and reporting their beliefs about the state of the world, which is an attribute of the company influencing the production of news. Some news will organically appear repeatedly while others will not and we focus on understand how memory and attention limitations shape over-reaction to repeated news.

Experimental Design Details
The experiment consists of three stages.

During the news generation and presentation
stage, we generate a valence-neutral set of eight facts stylized
as newspaper snippets drawn without replacement from a base set of
twelve facts about a fictional company. Each fact exists in a positive and a negative version.
Each fact is then assigned
a valence of positive or negative to define the subject-specific
set of eight facts. Each subject will be shown and asked to carefully
read two independent news pages, where each news page consists of
five facts drawn without replacement from the subject-specific set
of facts. The content of each fact remains the same on each news
page whereas the exact wording of each fact differs slightly from
page to page. Subjects will then be asked about their belief of the quality of the company's management conditional on the newspaper snippets they will have read in the belief elicitation stage. In the recognition stage, subjects will be
shown twelve facts: the eight facts in the subject-specific set and
the four other facts from the base set, and will be tasked with recognizing
whether or not they had read each snippet. This will be followed by a facts free recall task where subjects are asked to recall as many facts as they can, as accurately as possible. Finally, all the subjects will complete a words free recall task at the end (unrelated to the other sections) in order to get an independent measure of their recall performance. The experiment has two treatment arms. The first
treatment arm is the decay treatment: subjects complete a
simple three-minute long incentivized task; participants
in the no-decay control group complete the filler task at the
end of the experiment whereas the decay-inducing treatment group complete
the filler task in between the news generation and belief
elicitation stages. Screenshots of
the experiment from the subjects' perspective are available in the attached PDF.
Randomization Method
Randomization done by a computer.
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
700 individuals
Sample size: planned number of observations
700 invidivuals
Sample size (or number of clusters) by treatment arms
350 in Decay-Inducing treatment, 350 in No Decay treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
We used a bootstrap approach to power calculation using pilot data. See the attached PDF.

Institutional Review Boards (IRBs)

IRB Name
MIT Committee on the Use of Humans as Experimental Subjects (COUHES)
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?
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