The puzzles alluded to in the Preface and Introduction to this volume come in two major varieties. The first are puzzles about voter turnout itself, among them, why do people bother to vote at all? Why is turnout so relatively stable over time (compared to the enormous differences we see between countries)? Why does it decline when it does? And why (in some countries) does it not decline at all – or even rise? The second variety of puzzles have to do with how to study voter turnout. For example, is turnout an aggregate-level or an individual-level phenomenon? Can we understand it best by studying turnout change over time? By studying differences in turnout among countries or by studying why some individuals vote while others do not? What can we learn from the fact that turnout varies more among younger cohorts and less among established cohorts?

In this chapter we take these and other puzzles one at a time and use the process of going through them as an opportunity to set out not only the puzzles themselves but also the major approaches that have been employed in past research for solving them.

Why So Much Turnout Change – or Why So Little?

It has already been pointed out that turnout decline is not ubiquitous. Turnout did rise in the 2000 U.S. presidential election, for example.