This book asks two questions: who votes (and who does not), and does this difference matter? Updating Raymond E. Wolfinger and Steven J. Rosen­stone’s 1980 classic Who Votes?, Jan E. Leighley and Jonathan Nagler find that the answer to those questions has actually changed quite a bit over the past 40 years.

Most of the book focuses on demographic and institutional determinants of turnout. The first two empirical chapters analyze how the participation of core demographic groups has changed over time, focusing on education, income, race/ethnicity, age, and gender. While many of the findings will be familiar, several of these analyses will surprise even many political scientists. For example, the black–white turnout gap has been shrinking for more than a decade (so it is not simply an Obama effect), and the rich–poor turnout gap has not changed very much in the past 40 years.

The authors next turn to an examination of the effects of election adminis­tration laws on turnout, such as election day registration, motor-voter laws, and early voting. They find that while some electoral reforms have increased participation (most notably, absentee voting