Persuasion in Medicine: Experimental Evidence on Sender and Signal Effects

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.