ABSTRACT
Solidarity is a specific form of community—a willingness to sacrifice for the benefit of people who are part of some larger group, particularly the nation. This chapter reviews theory and research on the factors affecting solidarity. Proposed influences include economic inequality, ethnic heterogeneity, and the design of political institutions, particularly social welfare programs. Research finds some evidence that inequality and ethnic heterogeneity are associated with less solidarity; the evidence on institutional design is mixed. The chapter reviews several recent studies arguing that solidarity has declined over the last 50 years and concludes by discussing issues for future research.
