Electoral turnout is one of the most common indicators used to gauge the health of democracy, and many worry that conventional participation via the ballot box is plummeting in affluent societies, providing a danger signal for deeper troubles. If so, the reasons for this phenomenon remain a puzzle. The evidence for decline appears clearest in the United States, producing studies of The Disappearing American Voter and Why Americans Still Don't Vote. Detailed analysis of the American electorate by Miller and Shanks provides convincing evidence from the series of U.S. National Election Studies of persistent generational differences in turnout, with the post–New Deal generation least likely to cast a ballot, a pattern that has significant implications for the future of American democracy through the process of demographic replacement. Putnam couples the fall in American voting participation during the postwar era with a battery of evidence showing the broader erosion of civic mobilization in America since the 1960s and 1970s, indicated by the decline in formal attendance at political rallies and speeches, working for a political party, and writing to Congress, as well as in activism within informal associations in the local community.

Yet if historical experiences have produced widespread civic apathy among the postwar generation in America, it remains unclear whether these patterns are distinctive to the United States. Comparative studies continue to debate whether analogous trends are evident in other established democracies.