Measuring sensitive outcomes through online ballots

Last registered on November 25, 2025
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Pre-Trial

Trial Information

General Information

Title
Measuring sensitive outcomes through online ballots
RCT ID
AEARCTR-0017301
Initial registration date
November 21, 2025

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 25, 2025, 7:58 AM EST

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

Locations

Country
Egypt
Region

Primary Investigator

Name
Jules Gazeaud
Affiliation
CNRS, CERDI - Université Clermont Auvergne
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Other Primary Investigator(s)

PI Name
Bruno Crepon
PI Affiliation
CREST
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PI Name
Ahmed Elsayed
PI Affiliation
J-PAL MENA
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Additional Trial Information

Status
In development
Start date
2025-11-22
End date
2025-11-28
Keywords
Other
Additional Keywords
Sensive outcomes, online surveys
JEL code(s)
C81, C83
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
Abstract
A persistent challenge in empirical research is how to obtain truthful answers to sensitive questions, as misreporting can systematically bias estimates and misinform policy. In Crépon et al. (2025), we introduce the ballot-bag, a novel technique where respondents privately report their answers to one or more sensitive questions on anonymous paper sheets, which they then fold and place into a transparent bag held by an enumerator. We provide encouraging evidence on the method’s potential in the context of in-person surveys in Egypt. This add-on project seeks to adapt and test the method’s effectiveness in an online survey setting.
External Link(s)
https://www.iza.org/publications/dp/18072/unbiased-and-accurate-measuring-sensitive-outcomes-through-ballot-bag-surveys

Registration Citation

Citation
Crepon, Bruno, Ahmed Elsayed and Jules Gazeaud. 2025. "Measuring sensitive outcomes through online ballots." AEA RCT Registry. November 25. https://doi.org/10.1257/rct.17301-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
Intervention (Hidden)
Intervention Start Date
2025-11-22
Intervention End Date
2025-11-28

Primary Outcomes

Primary Outcomes (end points)
We aim to assess measurement differences between direct questioning and online ballots for four outcomes: 1) whether respondents plan to migrate to Europe without official papers; 2) whether they have ever consumed alcohol, even once; 3) whether they have ever used drugs, even once; and 4) whether they met any of their friends yesterday.
Primary Outcomes (explanation)
Outcome 1) is identical to the one used in Crépon et al. (2025). We include outcomes 2) and 3)—which we expect to be sensitive, especially in the Egyptian context and outcome 3)—because of a risk the prevalence of outcome 1) would be too low in online samples. Finally, outcome 4) is not expected to be sensitive and therefore serves as a placebo outcome; for this outcome, we do not expect any difference between the ballot method and direct questioning.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Respondents are recruited on the global online survey platform CINT. Given the nature of the sensitive outcomes, we focus on Egyptian males aged 18–35, residing in Egypt. We randomize respondents into two groups. In the first group, outcomes 1) and 4) are asked directly (DQ), while outcomes 2) and 3) are elicited using the ballot method (BB). In the second group, the assignment is reversed. We plan to estimate a basic linear probability model, regressing each outcome on a dummy indicating whether it is measured using BB. We expect BB to yield higher prevalence for sensitive outcomes (outcomes 1–3), given prior evidence that data on sensitive outcomes elicited using DQ often suffer from underreporting. To maximize statistical power, we will conduct one-sided tests with the alternative hypothesis that the BB coefficient is positive.
Experimental Design Details
Randomization Method
Randomization is done by computer directly within Qualtrics.
Randomization Unit
The unit of randomization is individual.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
The experiment will run for one week, or until 2,000 eligible individuals complete the survey.
Sample size: planned number of observations
The experiment will run for one week or until 2,000 eligible individuals complete the survey.
Sample size (or number of clusters) by treatment arms
Targets:
- 1,000 in Group 1 (DQ for outcomes 1–4, BB for outcomes 2–3)
- 1,000 in Group 2 (DQ for outcomes 2–3, BB for outcomes 1–4)
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 of the American University in Cairo
IRB Approval Date
2025-11-17
IRB Approval Number
2024-2025-374
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