Pink 2021.

Study characteristics
Methods	Study design: randomised controlled trial Type of publication: journal publication Setting and dates: online survey, March 17 to 24, 2021 Country: USA Language: English
Interventions	Republicans endorse condition (2‐minute excerpt from a speech given by former President Donald Trump in which he claimed credit for the vaccine development, criticised the Biden administration’s role, and encouraged people to get vaccinated) Democrats endorse condition (2‐minute excerpt from a speech given by President Joseph Biden, in which he detailed efforts to increase vaccinations and encouraged all Americans to get vaccinated) Neutral control condition (essay about the history of neckties and a video about how to tie a tie)
Population	Population: Republicans Age (Median): 47 Gender: 59% Female, 41% Male Ethnicity: NR Number of participants (recruited/allocated/evaluated): 1480 Inclusion/exclusion criteria: NR
Outcomes	Vaccination intention Attitudes toward the vaccine Willingness to encourage family and friends to vaccinate Belief that Republicans deserve credit for the vaccination program Belief that party leaders would want the respondent to vaccinate Percentage of Republicans the respondent believed will vaccinate
Notes	COI: NR Funding: Stanford Center on Philanthropy and Civil Society