Grasp all, lose all: information overload under ambiguity

Last registered on April 17, 2025
View Trial History

Pre-Trial

Trial Information

General Information

Title
Grasp all, lose all: information overload under ambiguity
RCT ID
AEARCTR-0015591
Initial registration date
April 07, 2025

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 17, 2025, 6:18 AM EDT

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

Locations

Country
Italy
Region
Lazio

Primary Investigator

Name
Gianmarco De Santis
Affiliation
Sapienza University of Rome
Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status
In development
Start date
2025-04-07
End date
2025-10-05
Keywords
Behavior
Additional Keywords
Ambiguity, Information overload
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Consumers often face decisions between ambiguous options, where the available information about potential outcomes can influence their choices. This study examines how the amount of information regarding outcome probabilities affects decision-making. We investigate whether increasing information reduces ambiguity and alters choice patterns. Through a laboratory experiment, participants explore different levels of probability information before selecting a lottery. Our findings contribute to a deeper understanding of how information availability shapes decision processes in uncertain environments.
External Link(s)

Registration Citation

Citation
De Santis, Gianmarco. 2025. "Grasp all, lose all: information overload under ambiguity." AEA RCT Registry. April 17. https://doi.org/10.1257/rct.15591-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention (Hidden)
Intervention Start Date
2025-04-07
Intervention End Date
2025-10-05

Primary Outcomes

Primary Outcomes (end points)
choice between lotteries (risk and ambiguity preferences); measure of overload of information
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment is based on lotteries, divided into two types: transparent lotteries and opaque lotteries. There are up to five possible prizes, each associated with a probability of winning. In transparent lotteries, participants are informed of the probabilities (though these may include some margin of error). In opaque lotteries, the probabilities remain unknown to participants, who can only estimate them based on collected information (which may also be subject to error). For transparent lotteries, errors stem from inaccuracies in the probabilities displayed to participants. For opaque lotteries, errors arise from the information participants gather through sampling. Participants are tasked with choosing between pairs of lotteries, which can consist of:
- Two transparent lotteries;
- Two opaque lotteries;
- One transparent lottery and one opaque lottery.
When selecting between opaque lotteries, participants do not initially know the probabilities associated with the prizes. However, they can draw samples freely to gather information before making their choice.
Experimental Design Details
Randomization Method
The order in which the lotteries are presented to participants is randomized by a computer, ensuring that each participant encounters a unique sequence of lottery pairs.
Randomization Unit
Individual unit
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
0
Sample size: planned number of observations
At least 150 university students
Sample size (or number of clusters) by treatment arms
At least 150 university students
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Comitato per la Ricerca della Luiss Libera Università Internazionale degli Studi Sociali Guido Carli
IRB Approval Date
2025-04-04
IRB Approval Number
N/A
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials