Hannover Blood Donation Behavior Experiment

Last registered on October 30, 2023
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Pre-Trial

Trial Information

General Information

Title
Hannover Blood Donation Behavior Experiment
RCT ID
AEARCTR-0012264
Initial registration date
October 15, 2023

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
October 17, 2023, 1:50 PM EDT

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

Last updated
October 30, 2023, 4:51 AM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Country
Germany
Region
Lower Saxony

Primary Investigator

Name
Alex Chan
Affiliation
Harvard University
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Other Primary Investigator(s)

PI Name
Annika Herr
PI Affiliation
Leibniz University Hannover
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PI Name
Arndt Reichert
PI Affiliation
Leibniz University Hannover
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Additional Trial Information

Status
In development
Start date
2023-10-16
End date
2024-12-25
Keywords
Behavior, Gender, Health
Additional Keywords
Identity
JEL code(s)
C93
Secondary IDs
H41; I1
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
We analyze the supply curve (willingness-to-accept, WTA) using BDM alongside real opportunities for blood donation. We investigate how information about peer blood donation behavior affects supply and whether a respondent's own blood donation aligning (or not) with their identity group peers influences their identification with that group. We assess the persistence of such identity shifts, employing various identification measures, including two incentivized ones. Additionally, we explore how the perceived scarcity of one's blood impacts WTA as a secondary inquiry.
External Link(s)

Registration Citation

Citation
Chan, Alex, Annika Herr and Arndt Reichert. 2023. "Hannover Blood Donation Behavior Experiment." AEA RCT Registry. October 30. https://doi.org/10.1257/rct.12264-2.0
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Experimental Details

Interventions

Intervention(s)
We will assess willingness to donate blood and estimate the supply curve for blood using BDM linked to actual option for blood giving with the Red Cross afterwards. We then measure how the supply of blood can be shifted by peer behavior (information provision), and measure how concordance with actions with peers in a identity group shifts an individual's identity closeness using incentivized measures and a Likert scale score. We then measure the persistence of such identity closeness shifts, again with an incentivized measures tied to consequential decisions.
Intervention Start Date
2023-10-30
Intervention End Date
2023-12-23

Primary Outcomes

Primary Outcomes (end points)
There are 2 sets of primary outcomes:
(1) WTA for blood giving and willingness to donate blood as a gift with no payment
(2) Degree of identification to different identity groups (women/men, LUH student, and others) - 3 measures (differences in the identification score on a 1-7 Likert Scale, difference amount shared in a trust game, difference in number of points allocated to policy issues popular with female voters vs male votes)
Primary Outcomes (explanation)
The WTA for blood giving will just be based on BDM, and the price is denominated in Euros. Willingness to donate blood as a gift is a Yes/No question.

The Degree of identification to different identity groups (women/men, LUH student, and others) will be calculated in the following way:
measures (differences in the identification score on a 1-7 Likert Scale, difference amount shared in a trust game, difference in number of points allocated to policy issues popular with female voters vs male votes)

See attached files for more details, as well as attached pre-registered hypotheses below in "Experimental Design".

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Using an actual blood giving campaign, we elicit individuals' willingness-to-accept to give their blood (in Euros). We conduct a BDM to estimate the WTA. We also ask for willingness to donate blood as a gift (no payment). The main information provision experiment provides the participants with one of 4 treatments: control; information about the sub-sample of a survey where women are more likely to give blood than men; information about the sub-sample of a survey where men are more likely to give blood than women; and information about the sub-sample of a survey where LUH students are more likely to give blood than those who are not LUH students. The secondary provides some participants about how scarce their blood is or control. The decision to donate and the BDM is conducted after information provision. We measure how much participants identify with female/male/university identities using three different mechanism (including a Likert scale question, and two incentivized measures: trust game and voting task) - the key measure is the difference in the degree of identity affinity between the identity group of interest (e.g. women) and that of the other group (e.g. men).

An important pre-experiment study is one where we conduct a survey in Hannover, Germany to survey individuals about their blood giving behavior along with demographic information and other relevant information (e.g. music preferences to create a minimal group paradigm for latter versions of the experiment). (Attached as "LUH-Blooddonation-pre-survey")

Experimental Design Details
Not available
Randomization Method
Done by computer - LimeSurvey in-built function
Randomization Unit
individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
NA
Sample size: planned number of observations
About 850 participants for in person campaign (expecting 10-20% attrition for each round). Note that we plan to do a similarly sized and similarly designed experiment in early 2024 via an email campaign (this experiment might involve some modifications in the identity groups studied and minor design changes). This follow-up experiment will be separately pre-registered and that trial's pre-registration number will be added to this one upon its creation.
Sample size (or number of clusters) by treatment arms
Information about peer donation experiment
(1) ~212 control, ~212 information treatment about sample where women more likely donated than men, ~212 information treatment about sample where men more likely donated than women, ~212 information treatment about sample where University of Hannover students more likely donated than people who are not students of University of Hannover

Information about blood scarcity experiment (some attrition, as this is only for survey 2)
(2) ~359 in control, ~359 in treatment with information about blood scarcity
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
Medizinische Hochschule Hannover Ethikkommission (Hannover Medical School Ethics Committee)
IRB Approval Date
2023-09-25
IRB Approval Number
11087_BO_K_2023
Analysis Plan