Action Bias or Illusion of Control? - Complexity Controlled, Within Subject

Last registered on June 08, 2025
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Pre-Trial

Trial Information

General Information

Title
Action Bias or Illusion of Control? - Complexity Controlled, Within Subject
RCT ID
AEARCTR-0015612
Initial registration date
March 20, 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 03, 2025, 10:55 AM EDT

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

Last updated
June 08, 2025, 9:05 PM EDT

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

Locations

Country
United States of America
Region
Virginia

Primary Investigator

Name
Aleksander Psurek
Affiliation
George Mason University
Contact Primary Investigator

Other Primary Investigator(s)

PI Name
Johanna Mollerstrom
PI Affiliation
George Mason University
PI Name
Kevin McCabe
PI Affiliation
George Mason University

Additional Trial Information

Status
In development
Start date
2025-07-01
End date
2025-10-15
Keywords
Behavior, Lab
Additional Keywords
illusion of control, action bias
JEL code(s)
C91
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
Abstract
In response to our previous laboratory experiment, pre-registered under "Action Bias or Illusion of Control?" (RCT ID: AEARCTR-0012294), we have identified the complexity of our willingness-to-pay / willingness-to-accept elicitation as a potential confounding factor. In this updated design, we again study the presence of an illusion of control and an action bias in two simple laboratory games. We designed these games to be as similar to each other as possible, with both involving the rolling of a pair of dice and relating to the values these dice come up on. The primary difference between these games is the presence of an element of luck (stochasticity, risk) in one game but not in the other, thus allowing us to separate the illusion of control from any present action bias.

In our previous value elicitation we used a third price auction stylized as an incrementing / decrementing price clock, though allowing asynchronous resolution. We similarly focused on a comparison across rather than within subject. In our new design, we are offering subjects a fixed price offer at two price points and have subjects play both dice games. In this way we simplify the value elicitation to decrease significantly the cognitive demands on subjects, while still testing for the presence of both the illusion of control and the action bias, and allow for tighter comparisons by using a within subject design. We do however give up the ability to measure the size of these effects at the individual level.
External Link(s)

Registration Citation

Citation
McCabe, Kevin, Johanna Mollerstrom and Aleksander Psurek. 2025. "Action Bias or Illusion of Control? - Complexity Controlled, Within Subject." AEA RCT Registry. June 08. https://doi.org/10.1257/rct.15612-2.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention (Hidden)
Intervention Start Date
2025-07-01
Intervention End Date
2025-10-15

Primary Outcomes

Primary Outcomes (end points)
We are interested in the percentage of subjects who buy (or do not sell) the right to personally roll the pair of dice.
Percentage of subjects who buy the right to roll dice personally in the stochastic game.
Percentage of subjects who buy the right to roll dice personally in the deterministic game.
Percentage of subjects who do not sell the right to roll dice personally in the stochastic game.
Percentage of subjects who do not sell the right to roll dice personally in the deterministic game.
Primary Outcomes (explanation)
The main variable, percentage of subjects who buy (or do not sell) their right to roll the dice is our measure of the illusion of control and the action bias together, under the stochastic dice game, and just the action bias in the case of the deterministic dice game.

We then take the difference between these two measures to estimate the effect of the illusion of control as a bias present on top of and distinct from the action bias.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We conduct a lab experiment employing computer interfaces and physical dice. Subjects participate in both a stochastic and a deterministic game involving a pair of dice. Subjects either roll the pair of dice themselves or the experimenter rolls the pair of dice on their behalf. The outcome of the dice roll is non-instrumental in determining the payoff for the subject and subject are informed of this fact. The order of the dice games is randomized and counterbalanced.

The subject determines who will roll the pair of dice for them, for a price. This price may be $0.25 or $1.00, depending on the treatment. In one treatment, the subject starts with the ability to roll the dice and they can sell this ability to the experimenter for a fixed price. In the other treatment, the experimenter starts with the ability to roll the dice and the subject can buy this ability from the experimenter for a fixed price. Regardless of who rolls the pair of dice, the payoffs from the dice rolling game are identical for the subjects.
Experimental Design Details
Randomization Method
Randomization is done at the session level, with the flipping of two coins determining the order of session treatments. The treatments are "sell high" and "sell low", as well as "buy high" and "buy low."

All treatments contain their own control groups, as the main analysis will pertain to within-subject variation. Within the subject, their behavior during the deterministic portion can be thought of as the control, with the stochastic treatments being the treatment.

Sessions will be ordered based on the flipping of two coins, with each outcome HH, HT, TH, and TT mapping to the treatments as such: HH = "sell high", HT = "sell low", TH = "buy high", and TT = "buy low."

Sessions are planned to have 16-20 participants with an expected number of 3 sessions per treatment. If there are less than 50 observations per treatment, additional sessions will be added with a random assignment to treatment, from those treatments with an insufficient observation count.
Randomization Unit
Experimental session (though individuals do not interact)
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
200
Sample size: planned number of observations
200
Sample size (or number of clusters) by treatment arms
50 per each treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
George Mason University IRB
IRB Approval Date
2023-10-12
IRB Approval Number
2106487-1, STUDY00000337
Analysis Plan

Post-Trial

Post Trial Information

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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