Abstract
We examine how information from trusted social media sources can shape knowledge and behavior when misinformation and mistrust are widespread. In the context of the COVID-19 pandemic in Zimbabwe, we partnered with a trusted civil society organization to randomize the timing of the dissemination of messages aimed at targeting misinformation about the virus to 27,000 newsletter WhatsApp subscribers. We examine how exposure to these messages affects individuals' beliefs about how to deal with the virus and preventative behavior. In a survey of 864 survey respondents, we find a 0.26σ increase in knowledge about COVID-19 as measured by responses to factual questions. Through a list experiment embedded in the survey, we further find that potentially harmful behavior-not abiding by lockdown guidelines-decreased by 30 percentage points. The results show that social media messaging from trusted sources may have substantively large effects not only on individuals' knowledge but also ultimately on related behavior.