Sequential Choice and Choice Overload

Last registered on July 10, 2023

Pre-Trial

Trial Information

General Information

Title
Sequential Choice and Choice Overload
RCT ID
AEARCTR-0011690
Initial registration date
July 05, 2023

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
July 10, 2023, 9:44 PM EDT

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

Locations

Region

Primary Investigator

Affiliation
UTS

Other Primary Investigator(s)

PI Affiliation
UTS
PI Affiliation
University of New South Wales

Additional Trial Information

Status
On going
Start date
2023-06-29
End date
2023-12-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
There is evidence in the literature that individuals engage in sequential search (i.e. they evaluate options in a choice menu in sequence) and satisficing (i.e. they stop search after reaching a certain utility threshold). Moreover, individuals have been shown to be overloaded by too much choice and, consequently, may prefer to restrict the size of the choice set. In this work, we develop and experimentally test a theory of sequential choice that predicts that individuals may prefer smaller choice sets to larger ones. In our theory, individuals may prefer smaller menus as they lower psychological costs from leaving options unevaluated and reduce the incentives to over-search.

In our experiment, subjects play a number of rounds where a round involves choosing an option from a choice set of either size 10 or 20 via a sequential procedure. An option is comprised of a number of attributes, each with some dollar value, and the sum of these attributes is the overall dollar value of that option. There are two treatments: a simple treatment where options are comprised of three attributes and a complex treatment in which options are comprised of seven attributes. Moreover, within each treatment, there are two parts. In Part A, the size of the choice set faced is fixed while in Part B, the size of the choice set is determined by the subjects themselves. Our objective is to analyze whether the following aspects are consistent with our theory: (1) how subjects make their choice sequentially, (2) whether subjects restrict the choice set, and (3) how (1) and (2) vary with the complexity of options.
External Link(s)

Registration Citation

Citation
Anufriev, Mikhail, Valentyn Panchenko and Benjamin Young. 2023. "Sequential Choice and Choice Overload." AEA RCT Registry. July 10. https://doi.org/10.1257/rct.11690-1.0
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
We employ a between-subjects design. Subjects are randomly assigned at the individual level to one of two treatments: a simple treatment and a complex treatment. In the simple treatment, options require the sum of three numbers to be evaluated. Instead, in the complex treatment, options require the sum of seven numbers to be evaluated.
Intervention Start Date
2023-06-29
Intervention End Date
2023-12-31

Primary Outcomes

Primary Outcomes (end points)
The dollar value of an option chosen in a given round.
The dollar values of options evaluated but not chosen in a given round.
An estimate of their minimum willingness to accept an option.
The number of options evaluated before ending a round.
How long a subject holds an option as a default before selecting it as their choice.
Whether the subject chooses to restrict the size of the choice menu.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Demographics and answers to cognitive test questions.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
In our experiment, subjects play a number of rounds where a round involves choosing an option from a choice set of either size 10 or 20 via a sequential procedure. An option is comprised of a number of attributes, each with some dollar value, and the sum of these attributes is the overall dollar value of that option. The process by which a choice is made within a round is sequential. First, subjects compare two options from the choice set and decide which they prefer. Next, they decide whether to continue on to view an additional option to evaluate or to lock in their choice and end the round. If they end the round, then their selected option is their choice for that round. Instead, if they choose to evaluate another option, they compare their best option thus far to a new, as yet unevaluated, option. The procedure repeats until a subject either chooses to lock in an option and end the round or evaluates all available options in that round.

There are two parts to the experiment: Part A and Part B. In Part A of the experiment the size of the choice set is fixed in a given round at either 10 or 20. In Part B of the experiment, subjects are able to choose the menu size. Specifically, at the start of Part B, subjects are asked if they prefer the menu size to be 10 or 20. Their choice at this stage is implemented for all rounds in Part B.

The experiment is incentivised. In particular, we choose one of the rounds subjects participate in across both Part A and Part B. We then provide the subjects the dollar value (in AUD) of the option they chose in that round (as calculated by the sum of that options attributes). In addition, subjects are paid a show-fee of 10AUD.
Experimental Design Details
Randomization Method
Randomisation done by computer program
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
Approximately 20 individuals in each treatment for a pilot
Sample size: planned number of observations
Approximately 20 individuals in each treatment for a pilot
Sample size (or number of clusters) by treatment arms
Approximately 20 individuals in each treatment for a pilot.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
UTS Behavioural Lab
IRB Approval Date
2023-07-04
IRB Approval Number
ETH23-8040

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