Persuasion in Medicine: Experimental Evidence on Sender and Signal Effects

Prior research has found that patient-doctor racial concordance is important for increasing the demand for preventive healthcare among low-income African American men, particularly for invasive services. Although results were consistent with better communication as the mechanism, other explanations, such as differential messaging or doctor quality, were difficult to exclude. To eliminate confounding from these factors and uncover which aspects of communication are particularly important for influencing health behaviors, we propose a pilot RCT randomizing black and white adult male subjects to infomercials featuring black and white male physician-actors. The content of the infomercial is the safety and effectiveness of adult seasonal flu vaccination. We hold the signal (i.e. the infomercial script) constant, while varying features of the sender (i.e. race and authority). By including black and white respondents, we test whether concordance effects differ across race. Our primary outcomes of interest are prior/posterior beliefs about the risk/benefits of the flu shot, perceptions of the sender, willingness-to-pay (WTP) for a free flu shot voucher, level of attention and recall from the infomercial video, and redemption of said voucher.