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How does choice affect learning?
Last registered on April 20, 2021


Trial Information
General Information
How does choice affect learning?
Initial registration date
April 19, 2021
Last updated
April 20, 2021 6:33 AM EDT
Primary Investigator
Central European University
Other Primary Investigator(s)
PI Affiliation
Vienna University of Economics and Business
Additional Trial Information
In development
Start date
End date
Secondary IDs
In many cases people receive information about products after their choice, which in turn affects future buying/selling decisions (e.g. financial assets, switching markets). This project studies how choice itself - beyond the effect of ownership - changes how people use information to update their beliefs about products. In the lab, using a between-subject design, participants learn about the fundamental quality
of financial investments by observing price changes. We examine how they update beliefs after positive (e.g. price increase) and negative (i.e. price decrease) signals. The goal is to compare people who choose the investments themselves to people who receive the same investments exogenously. This comparison allows us to isolate the effect of choice from the effect of ownership.
External Link(s)
Registration Citation
Hajdu, Gergely and Balazs Krusper. 2021. "How does choice affect learning?." AEA RCT Registry. April 20. https://doi.org/10.1257/rct.7578-1.0.
Experimental Details
Participants learn about the fundamental quality of financial investments by observing price changes. We examine how they update beliefs after positive (e.g. price increase) and negative (i.e. price decrease) signals. Participants own some of the investments: in the Choice treatment they choose themselves while in the Allocation they receive investments exogenously.
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
Belief changes in percentage points.
Primary Outcomes (explanation)
Secondary Outcomes
Secondary Outcomes (end points)
Recall accuracy of previous price changes and beliefs.
Secondary Outcomes (explanation)
Experimental Design
Experimental Design
Participants face 6 investment opportunities in the experiment. Each investment has the same initial price and a fixed but unknown quality s_i. In each round, each investment price either increases - with probability s_i -, or decreases - with probability 1-s_i. There are 20 rounds. In each round, participants observe the sequence of all previous prices and they have to predict each investment's probability of a price increase. Participants are incentivized to make accurate predictions.

Participants are randomly assigned to one of two treatment conditions after round 4. In the Choice condition, they have to choose 3 investments. In the Allocation condition, they receive the 3 investments with the highest current prices. In both conditions, ownership means that the participants receive a bonus based on the the final price of the own investments. Choosing or receiving investments will come as a surprise in round 4.

To learn about the mechanism, we add two unexpected recall questions. First, we ask participants about price changes of two randomly selected investments in the previous round. They receive this question in a randomly selected round between round 14 and 16. Second, we ask participants about their predictions of two randomly selected investment in the previous round. They receive this question 3 rounds after the price recall task. For each recall task, participants are incentivized to give accurate answers.
Experimental Design Details
Randomization Method
Randomization is done by the computer.
Randomization Unit
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
750 participants.
Sample size: planned number of observations
750 participants * 6 investments * 16 rounds = 72,000 observations
Sample size (or number of clusters) by treatment arms
Choice treatment: 375 participant
Allocation treatment: 375 participant
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB Name
Central European University Economics Doctoral Committee
IRB Approval Date
IRB Approval Number
Analysis Plan

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Study Withdrawal
Is the intervention completed?
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Data Publication
Data Publication
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Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)