Default Effects in Web Search

Last registered on February 27, 2024

Pre-Trial

Trial Information

General Information

Title
Default Effects in Web Search
RCT ID
AEARCTR-0012884
Initial registration date
January 25, 2024

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
January 31, 2024, 1:16 PM EST

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

Last updated
February 27, 2024, 2:46 PM EST

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

Locations

Region

Primary Investigator

Affiliation
Microsoft Research

Other Primary Investigator(s)

PI Affiliation
University of Pennsylvania
PI Affiliation
Stanford
PI Affiliation
Wharton
PI Affiliation
MIT

Additional Trial Information

Status
In development
Start date
2024-01-23
End date
2024-03-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
We cannot risk that participants become aware of this information before the study is complete. Please refer to the pre-analysis plan for more information.
External Link(s)

Registration Citation

Citation
Allcott, Hunt et al. 2024. "Default Effects in Web Search." AEA RCT Registry. February 27. https://doi.org/10.1257/rct.12884-1.1
Experimental Details

Interventions

Intervention(s)
Please refer to the pre-analysis plan for more information.
Intervention Start Date
2024-01-23
Intervention End Date
2024-03-31

Primary Outcomes

Primary Outcomes (end points)
We cannot risk that participants become aware of this information before the study is complete. Please refer to the pre-analysis plan for more information.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We cannot risk that participants become aware of this information before the study is complete. Please refer to the pre-analysis plan for more information.
Experimental Design Details
We randomize Google and Bing users into different conditions that nudge or incentivize them to search on the other search engine. Please refer to the pre-analysis plan for more information.
Randomization Method
We cannot risk that participants become aware of this information before the study is complete. Please refer to the pre-analysis plan for more information.
Randomization Unit
We cannot risk that participants become aware of this information before the study is complete. Please refer to the pre-analysis plan for more information.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
We cannot risk that participants become aware of this information before the study is complete. Please refer to the pre-analysis plan for more information.
Sample size: planned number of observations
We cannot risk that participants become aware of this information before the study is complete. Please refer to the pre-analysis plan for more information.
Sample size (or number of clusters) by treatment arms
We cannot risk that participants become aware of this information before the study is complete. Please refer to the pre-analysis plan for more information.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
MIT Committee on the Use of Humans as Experimental Subjects
IRB Approval Date
2023-09-18
IRB Approval Number
2308001088
Analysis Plan

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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