Persuasion in Medicine: Experimental Evidence on Sender and Signal Effects
Persuasion in Medicine: Experimental Evidence on Sender and Signal Effects
The aim of the study is to identify what sender/signal combinations are most persuasive in
 encouraging low socioeconomic males living in the U.S. to take-up seasonal flu vaccination.
 The investigators plan to recruit male subjects and randomly assign them to four persuasion
 treatments: three of which vary dimensions of the sender of a medical recommendation (racial
 concordance, gender concordance, and authority treatments) and one which varies the signal
 (standard vs. empathetic). Specifically, the investigators will show subjects videos of
 either Black or white actors/actresses providing scripted information on the flu vaccination.
 The investigators will randomize the race of the sender and if the subject is Black, also
 randomize the authority of the sender, with the actor portraying either a doctor or a
 layperson. Conditional on project funding, subjects assigned to a concordant sender will have
 the gender of the sender randomized. In addition, the investigators will vary the script used
 in the experiment between one that acknowledges past injustices (indicated as an empathetic
 script hereafter) and one that does not (indicated as a standard script hereafter). The
 investigators will provide subjects a free flu shot coupon and elicit the price at which
 subjects would be willing to give up this coupon for a cash reward. Lastly, in light of the
 relevance of vaccination take-up in combating COVID-19 pandemic, the investigators will
 assess demand for information about a COVID-19 vaccine, with subjects invited to receive
 results of a safety and efficacy review from a trusted or standard source. The design
 requires collection of baseline and endline surveys combined with administrative data from
 pharmacies about coupon redemption. The primary outcomes of interest are posterior beliefs
 about seasonal flu vaccination, demand and willingness-to-pay (WTP) for a free flu shot
 coupon, redemption of the coupon, and demand for information about a COVID-19 vaccine.
The investigators will recruit approximately 3350 African-American or Caucasian adult males
 with a high-school diploma or less. A pilot study, which ran during the 2019-20 flu season,
 recruited approximately 850 subjects, and a planned scale-up will recruit an additional 2500
 subjects during the 2020-21 flu season. The investigators will oversample African American
 individuals, emphasizing low-income and minority men because these characteristics are
 correlated with lower relative take-up of flu vaccination. After informed consent is
 obtained, subjects will be asked about sociodemographic information (age, education, income
 and marital status), healthcare experience and past medical history, knowledge and beliefs
 about flu vaccination, and location of the nearest pharmacy. The investigators will then
 randomly assign the adult male subjects to videos which contain one of Black or white actors
 playing the role of either a doctor or a layperson as well as different scripts. The content
 of the infomercial will be the safety and effectiveness of adult seasonal flu vaccination.
 After the video, the investigators will obtain information on beliefs regarding vaccination,
 feedback on the video, attention to the video and willingness-to-pay for a flu shot coupon.
 The final baseline module will consist of a randomly assigned invitation to receive the
 results of an upcoming review of a COVID-19 vaccine, with subjects assigned to receive
 information from a trusted or standard source. The investigators will track flu coupon
 redemption, which is redeemable at most pharmacies nationwide.
Inclusion Criteria:

 -  Age: See above.

 -  Education: Less than a college degree.

 -  Gender: Male.

 -  Race: Caucasian or African American.

 -  Miscellaneous: Has not received the flu shot in the current flu season yet.

 -  Miscellaneous: Has sound on his device turned on.

 Exclusion Criteria:

 -  Fast survey-taking: subjects who are among the 5% fastest in terms of total time spent
 on survey within race and treatment group.

 -  Nonsense answers (those that do not have decipherable English) in the open text
 sections that suggest low effort.

 -  Inconsistent responses to questions (such as being willing to give up $10 to receive a
 flu coupon but not $1).

 -  Repeat survey takers as indicated by duplicate emails or IP addresses in survey data.