The participation gap arises from two contrasting trends. Voting turnout is generally declining, especially among citizens with lower social status. At the same time, more people are participating in civil-society activity, contacting government officials, protesting, and using online activism and other creative forms of participation. These non-electoral activities are growing because of more activity by higher-social-status citizens. The democratic principle of the equality of voice is eroding. The politically rich are getting richer—and the politically needy exercise less voice. This book assembles an unprecedented set of international public-opinion surveys to identify the individual, institutional, and political factors that produce these trends. New forms of activity place greater demands on participants, raising the importance of social-status skills and resources. Civil-society activity further widens the participation gap. New norms of citizenship shift how people participate. And generational change and new online forms of activism accentuate this process. Effective and representative government requires a participatory citizenry and equal voice, and participation trends are undermining these outcomes. The Participation Gap both documents the growing participation gap in contemporary democracies and suggests ways that we can better achieve their theoretical ideal of a participatory citizenry and equal voice.