Highly educated citizens vote at much lower rates than less educated citizens in some countries. By contrast, electoral participation exhibits no such bias in other countries as diverse as Spain, Denmark, and South Korea. This book describes the levels of unequal participation in thirty-six countries worldwide, examines possible causes of this phenomenon, and discusses its consequences. Aina Gallego illustrates how electoral procedures, party and media systems, unionization, and income inequality impact unequal participation through an original combination of cross-national survey data and survey experiments