Smiles in Profiles: Improving Fairness and Efficiency Using Estimates of User Preferences in Online Marketplaces

Last registered on November 15, 2024

Pre-Trial

Trial Information

General Information

Title
Smiles in Profiles: Improving Fairness and Efficiency Using Estimates of User Preferences in Online Marketplaces
RCT ID
AEARCTR-0014771
Initial registration date
November 12, 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
November 15, 2024, 1:49 PM EST

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

Locations

Region

Primary Investigator

Affiliation
Stanford University

Other Primary Investigator(s)

PI Affiliation
Stanford University
PI Affiliation
Northwestern University
PI Affiliation
Carnegie Mellon University

Additional Trial Information

Status
In development
Start date
2021-11-12
End date
2025-01-01
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Online platforms face the dual challenge of promoting fairness (ensuring non-discriminatory access) and maximizing efficiency (optimizing revenue generation). In this study, we explore the impact of profile image characteristics on these goals within a micro-lending marketplace. Using computer vision algorithms and observational data, we previously found that borrowers' choices in profile creation can influence both fairness and efficiency. To further investigate these findings, we are conducting a web-based randomized survey experiment. This experiment introduces profile images generated with Generative Adversarial Networks (GANs), which vary systematically by specific visual features—such as age, hair, and the presence of glasses. In addition to testing the effect of these features on lender demand, the experiment includes incentives to encourage realistic engagement with lending decisions.
External Link(s)

Registration Citation

Citation
Athey, Susan et al. 2024. "Smiles in Profiles: Improving Fairness and Efficiency Using Estimates of User Preferences in Online Marketplaces." AEA RCT Registry. November 15. https://doi.org/10.1257/rct.14771-1.0
Experimental Details

Interventions

Intervention(s)
In the intervention, subjects are shown 8 pairs of borrower profiles. 7 of them are generated using a computer vision algorithm and 1 pair consists of actual images of borrower active on Kiva.org. Subjects are then asked to pick the preferred image in each pair. Images randomly vary by the age of the person shown in the image, and whether the person wears glasses or the style of their hair.
Intervention (Hidden)
Intervention Start Date
2024-11-14
Intervention End Date
2024-11-16

Primary Outcomes

Primary Outcomes (end points)
The primary outcome is whether the subject choose a profile or not.

Primary Outcomes (explanation)
We will use the data on subjects' choices to estimate the impact of age, glasses, and hair style in determining the choice.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Subjects recruited on Proflic.co receive one of fifteen predefined protocols. Protocols consists of 8 pairs of images in which age of the person in the image and whether the person wears glasses or not and the hair style, is randomly assigned. images in 7 pairs are generated using a computer vision algorithm. Subjects are asked to choose one of the profiles in each pair. Thus, a treatment is a pair of images a subject is choosing from. Additionally, we include three attention checks; first, we ask for the reason people participate in microfinance; second, for the explanation of the choice decision, and third, for the occupation of the person shown in the previous slide.
Experimental Design Details
Randomization Method
Randomization is made by computer.
Randomization Unit
The unit of the randomization is an experimental session. Experimental sessions are choice instances in which a subject chooses between two profiles.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
In an experimental protocol there are 16 slots. Borrower profiles, both those generated using AI and those of actual Kiva borrowers, are randomly assigned to these 16 slots. We generate 15 such protocols. 400 subjects are randomly assigned to these 15 protocols. The unit of the randomization is thus an experimental session. Experimental sessions are choice instances in which a subject chooses between two profiles.
Sample size: planned number of observations
3200 choice instances
Sample size (or number of clusters) by treatment arms
3200 choice instances
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Each experimental subject observes 16 profiles. Thus, 400 subjects generate 6400 observations. For each feature, the treated group is a profile for which the feature takes the value of 1 and the control group when the value is 0. The size of treatment and control groups is 3200, and the baseline probability of being selected 0.5. Using the two-sample proportion test, we find that the minimum detectable effect is a 2.47 percentage point difference between treatment and control in the probability of being selected. We have the same minimum detectable effect for all features of interest.
IRB

Institutional Review Boards (IRBs)

IRB Name
Northwestern University Institutional Review Board
IRB Approval Date
2024-08-06
IRB Approval Number
STU00222341
Analysis Plan

Analysis Plan Documents

Smiles in Profiles: Improving Fairness and Efficiency Using Estimates of User Preferences in Online Marketplaces Pre-analysis Plan Experiment 2

MD5: 94bd84beb0352aa1637f8618696de7c9

SHA1: 92e9c0c2fca9ff892f13bc5800e3e2f5cc9b5172

Uploaded At: November 12, 2024

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