Social solidarity is a critical tool in the response to the COVID-19 pandemic, as political leaders call for major disruptive changes to everyday life and sacrifices for collective well-being. In a white paper for the COVID-19 Rapid Response Impact Initiative of the Edmond J. Safra Center for Ethics at Harvard University, CMES faculty affiliate Melani Cammett and MIT's Evan Lieberman shed light on the nature of social solidarity; how it might affect the attitudinal and behavioral changes needed to confront the crisis; potential obstacles to solidarity as a result of the particular biomedical properties of the virus and of society and politics more generally; and factors aiding in the building of solidarity. They conclude with several plausible strategies to foster solidarity, including those focused on public messaging – such as cueing "linked fate" or emphasizing high-risk behaviors rather than groups – and policies – such as fair and transparent rules for public health tools, sustained economic support funds, and excess profits taxes. Promoting solidarity must supplement "technical" solutions because the efficacy of the latter will depend on the former. Read the white paper here.