Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We investigate how religion concordance influences the effectiveness of preventive health campaigns. Conducted during the early stages of the COVID-19 pandemic in two major Indian cities marked by Hindu–Muslim tensions, we randomly assigned a representative sample of slum residents to receive either a physician-delivered information campaign promoting health-related preventive practices, or uninformative control messages on their mobile phones. Messages, introduced by a local citizen (the sender), were cross-randomized to start with a greeting signaling either a Hindu or a Muslim identity, manipulating religion concordance between sender and receiver. We found that doctor messages increased compliance with recommended practices and beliefs in their efficacy. Our findings suggest that the campaign’s impact is primarily driven by shared religion between sender and receiver, leading to increased message engagement and compliance with recommended practices. Additionally, we observe that religion concordance helps protect against misinformation.