Peer Effects in Online Environments: Evidence from MovieLens

Last registered on April 19, 2018

Pre-Trial

Trial Information

General Information

Title
Peer Effects in Online Environments: Evidence from MovieLens
RCT ID
AEARCTR-0002905
Initial registration date
April 16, 2018

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 19, 2018, 11:20 AM EDT

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

Locations

Primary Investigator

Affiliation

Other Primary Investigator(s)

Additional Trial Information

Status
In development
Start date
2018-04-18
End date
2018-07-25
Secondary IDs
Abstract
I conduct a field experiment on MovieLens to examine how various factors mediate peer effects.
External Link(s)

Registration Citation

Citation
Leung, Weiwen. 2018. "Peer Effects in Online Environments: Evidence from MovieLens." AEA RCT Registry. April 19. https://doi.org/10.1257/rct.2905-1.0
Former Citation
Leung, Weiwen. 2018. "Peer Effects in Online Environments: Evidence from MovieLens." AEA RCT Registry. April 19. https://www.socialscienceregistry.org/trials/2905/history/28526
Experimental Details

Interventions

Intervention(s)
Intervention Start Date
2018-04-18
Intervention End Date
2018-07-25

Primary Outcomes

Primary Outcomes (end points)
Contributions of ratings and tags, number of logins, number of movies added to the database
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We manipulate group size, mean of group contribution, and standard deviation of group contribution to examine how these factors mediate the treatment effect of leaderboards. We also are able to examine the effect of leaderboards themselves.
Experimental Design Details
Randomization Method
Randomization done by a Python script
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
Not applicable as randomization is done at the individual level
Sample size: planned number of observations
Around 3000
Sample size (or number of clusters) by treatment arms
The main aim is to examine how the treatment effect of a leaderboard is affected by group size, mean of group contributions, as well as standard deviation of group contributions. The treatment effect of a leaderboard will be also estimated, but through within-subject/regression discontinuity/difference-in-differences methods. As such, this section is not really applicable.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
University of Minnesota
IRB Approval Date
2018-08-17
IRB Approval Number
STUDY00000968

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