Increasing Organ Donor Registration as a Means to Increase Transplantation: An Experiment With Actual Organ Donor Registrations (Wave 2)

Last registered on June 24, 2024


Trial Information

General Information

Increasing Organ Donor Registration as a Means to Increase Transplantation: An Experiment With Actual Organ Donor Registrations (Wave 2)
Initial registration date
June 10, 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
June 24, 2024, 9:42 AM EDT

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



Primary Investigator

Wharton School - University of Pennsylvania

Other Primary Investigator(s)

PI Affiliation
Stanford University

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
The U.S. has a severe shortage of organs for transplant. Recently — inspired by research based on hypothetical choices — jurisdictions have tried to increase organ donor registrations by changing how the registration question is asked. We evaluate these changes with a novel "field-in-the-lab" experiment, in which subjects change their real organ donor status, and with new donor registration data collected from U.S. states. A "yes/no" frame is not more effective than an "opt-in" frame, contradicting conclusions based on hypothetical choices, but other question wording can matter and asking individuals to reconsider their donor status increases registrations.
External Link(s)

Registration Citation

Kessler, Judd and Alvin Roth. 2024. "Increasing Organ Donor Registration as a Means to Increase Transplantation: An Experiment With Actual Organ Donor Registrations (Wave 2)." AEA RCT Registry. June 24.
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Organ donor registration status.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
In Wave 2 of our field-in-the-lab experiment, 142 participants were recruited to the Computer Lab for Experimental Research (CLER) at Harvard University on one of 4 dates in August 2016. Recruitment information informed potential participants they needed a Massachusetts driver's license, learner's permit, or state identification card and the last four digits of their social security number to participate in the study, but participants were not informed in advance that the study concerned organ donation. Participants received $15 for participating in the study. Everyone who arrived at the laboratory and had the required Massachusetts credentials was allowed to participate.

Subjects were randomly asked about organ donor registration with an opt-in frame or a yes/no frame. In the opt-in frame, subjects were given the opportunity to change their organ donor status by checking a box and clicking "continue". Leaving the box blank and clicking continue kept their organ donor registration status unchanged. In the yes/no frame, subjects were provided with two radio buttons, one that would add them to the organ and tissue donor registry (or leave them on the registry if they were already on it) and one that would leave them off the registry (or remove them from the registry if they were already on it). In the yes/no frame, subjects were required to check one of the buttons and click "continue" before continuing with the rest of the study.
Experimental Design Details
Randomization Method
Randomization was conducted via computer software housed in the Computer Lab for Experimental Research (CLER) at Harvard University.
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
142 individuals.
Sample size: planned number of observations
142 individuals.
Sample size (or number of clusters) by treatment arms
84 individuals in the yes/no frame and 58 individuals in the opt-in frame.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
University of Pennsylvania IRB
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials