Pay Transparency and Employer Wage-Setting: An Online Experiment

Last registered on September 28, 2026
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Pre-Trial

Trial Information

General Information

Title
Pay Transparency and Employer Wage-Setting: An Online Experiment
RCT ID
AEARCTR-0019808
Initial registration date
September 24, 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
September 28, 2026, 9:38 AM EDT

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

Locations

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Primary Investigator

Name
Ipek Mumcu
Affiliation
University of Exeter
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Other Primary Investigator(s)

PI Name
Elif Kubilay
PI Affiliation
University of Essex
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PI Name
Duygu Ozdemir
PI Affiliation
University College London
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PI Name
Inci Lal
PI Affiliation
University of Essex
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Additional Trial Information

Status
In development
Start date
2026-09-24
End date
2026-10-30
Keywords
Behavior, Gender
Additional Keywords
Pay transparency; gender wage gap
JEL code(s)
J31, J16, J38
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This study examines how the level of detail in mandatory pay transparency affects employers’ wage-setting and position-assignment decisions. Employers are randomly assigned to one of three conditions: no transparency, mandatory disclosure of the aggregate firm-level gender pay gap, or mandatory disclosure of gender pay gaps separately by position. Employers assign male and female employees to manager and clerk positions and set their wages, while employees complete incentivized real-effort tasks. The study measures how transparency affects the overall gender wage gap and whether employers respond by changing wages, position assignments, or both.
External Link(s)

Registration Citation

Citation
Kubilay, Elif et al. 2026. "Pay Transparency and Employer Wage-Setting: An Online Experiment." AEA RCT Registry. September 28. https://doi.org/10.1257/rct.19808-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
The intervention consists of varying the pay-transparency regime that employers know will apply to the wage and position decisions they make for employees. Employers are randomly assigned to one of three conditions: no transparency, mandatory aggregate firm-level gender pay-gap disclosure, or mandatory position-level gender pay-gap disclosure. In the no-transparency condition, employees receive information only about their own position and wage. In the aggregate-transparency condition, employees additionally receive information on the firm’s gender composition and overall gender pay gap. In the position-level transparency condition, employees instead receive gender pay-gap information separately for manager and clerk positions, together with the gender composition of each position. All disclosed information is calculated directly from the employer’s actual wage and position assignments.
Intervention Start Date
2026-09-24
Intervention End Date
2026-10-30

Primary Outcomes

Primary Outcomes (end points)
The primary outcome is the employer-level/company-level percentage gender wage gap.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary outcomes include average wages assigned separately to male and female employees, the number of women assigned to manager positions, whether at least one woman is assigned as a manager, the manager–clerk wage differential, and gender wage gaps by employee performance group. We also examine employer perceptions and reported wage-setting considerations, as well as firm productivity and employer earnings for implemented firms.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We conduct a three-wave, asynchronous online experiment with UK-based participants recruited through Prolific. Employers are randomly assigned, with equal probability and stratified by employer gender, to one of three pay-transparency regimes: no transparency, mandatory aggregate firm-level gender pay-gap disclosure, or mandatory position-level gender pay-gap disclosure. Employers assign six employee profiles to manager and clerk positions and set their wages subject to a fixed wage budget. Employees complete incentivized real-effort tasks and are matched to employer-assigned profiles based on gender and performance group. A randomly selected subset of employer decisions is implemented, determining employees’ positions, wages, and the pay information they receive.
Experimental Design Details
Not available
Randomization Method
Randomization at the individual level within the survey. We implement stratified randomization by employer's gender.
Randomization Unit
individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
600
Sample size: planned number of observations
600
Sample size (or number of clusters) by treatment arms
200 in each of the treatment arms.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
With approximately 200 employers in each treatment arm, a two-sided significance level of 5%, and 80% power, the minimum detectable effect for either pairwise comparison is approximately 0.28 standard deviations of the primary outcome.
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
FESE UEBS Ethics Committee
IRB Approval Date
2026-08-19
IRB Approval Number
13696239
Analysis Plan

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