Observational evidence suggests that social trust, i.e., trust in others, and the closely related concept of social capital play a critical role in compliance with government policy, particularly in regards to public responsiveness to measures intended to curb the spread of the novel coronavirus. We use a survey experiment to causally estimate the impact of altering social trust on compliance with a range of policies intended to combat the COVID-19 pandemic. Utilizing an instrumental variable approach, we are able to alter reported social trust, but find null effects in regards to compliance with COVID-19 mitigation measures. We speculate on several explanations for this finding.