Freelancers Advertising RCT

Last registered on August 20, 2026
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Pre-Trial

Trial Information

General Information

Title
Freelancers Advertising RCT
RCT ID
AEARCTR-0019372
Initial registration date
August 12, 2026

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
August 20, 2026, 8:43 AM EDT

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

Locations

Country
United States of America
Region

Primary Investigator

Name
Navdeep Sahni
Affiliation
Stanford University
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Other Primary Investigator(s)

PI Name
Caio Waisman
PI Affiliation
Northwestern University
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PI Name
Daniel Haanwinkel
PI Affiliation
UCLA
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Additional Trial Information

Status
Completed
Start date
2019-05-01
End date
2019-07-31
Keywords
Behavior, Firms & Productivity, Labor
Additional Keywords
freelancers, advertising, sponsorship, platforms, intermediaries
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
The study is done in collaboration with a large freelancer platform.
Prior to the experiment, the platform had Premium freelancers: those who pay the platform for services such as ability to reach employers and get more visibility.

The experiment randomized employers into treatment and control group.

Control group got the status quo experience with no sponsored listings.

Treatment group employers were eligible to see sponsored listings featuring Premium freelancers. For any search conducted by a treatment group employer, the platform searched for the most relevant Premium freelancers; if a relevant Premium freelancer was found, the platform placed the most relevant one on top of the listings shown to the employer. At most one sponsored listing was shown in a page.

All other aspects of the platform (including other ways in which Premium freelancers are visible) is same across treatment and control employers.
External Link(s)

Registration Citation

Citation
Haanwinkel, Daniel, Navdeep Sahni and Caio Waisman. 2026. "Freelancers Advertising RCT." AEA RCT Registry. August 20. https://doi.org/10.1257/rct.19372-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
The intervention was promotion of Premium freelancers (FLs). Treatment group employers were eligible to see sponsored listings featuring Premium FLs.
Intervention (Hidden)
Intervention Start Date
2019-05-01
Intervention End Date
2019-07-31

Primary Outcomes

Primary Outcomes (end points)
Clicks on freelancers, sponsored and non-sponsored; interview invitations; hires
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We conducted an employer-level randomized field experiment in partnership with a large online labor platform. The experiment ran from April through July, 2019. Employer accounts were assigned with equal probability to a treatment group or a control group when they entered the experiment during the study period. The realized analysis sample consisted of 464,986 employers: 233,211 assigned to treatment and 231,775 assigned to control.

Employers assigned to the control group experienced the status quo version of the platform, without ads for workers. Employers assigned to the treatment group were eligible to see premium-membership workers displayed as sponsored listings (ads) on worker search and recommendation pages. For each page request, the platform first generated its usual organic list of workers using its existing matching algorithms. It then identified premium-membership workers within that organic list. On the first page of results, the highest organically ranked premium worker was displayed as an ad above the organic listings; on the second page, the second-highest organically ranked premium worker was displayed as an ad, and so forth. The ad added an additional listing rather than replacing an organic listing. A similar procedure was used for worker recommendations shown to employers after they created a job posting.

Treatment assignment determined eligibility for advertising rather than guaranteeing exposure. An ad could be displayed only when the underlying organic candidate set contained a premium-membership worker.

Outcomes are measured at the employer level during the 60 days following assignment. The outcomes include whether and how frequently an employer clicked on worker profiles, invited workers to apply for jobs, and hired workers. These outcomes are measured for all workers and separately according to workers’ premium-membership status. The primary analysis follows an intention-to-treat design, comparing employers according to their randomly assigned treatment status.
Experimental Design Details
Randomization Method
Randomization done by a computer
Randomization Unit
Unit: employer
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
464,986 employers
Sample size: planned number of observations
500,000 employers
Sample size (or number of clusters) by treatment arms
Treatment: 233,211 employers
Control: 231,775 employers
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

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