How do we measure unequal? The who, where, what, when, and how of inequality

How can we quantify inequality? There are many different types of inequality that we could talk about, and many different sources of data that could be used to measure inequality. A great deal of the public debate surrounding inequality is often at cross-purposes because different people have different ideas about what constitutes inequality and how they choose to measure it. Many people believe in equality as a principle, but there is often little agreement about what should be made equal. Here, we examine the many ways that economic inequality can be defined and how we can bring data—or sometimes fail to bring data—to each of these definitions. Who are we talking about when we talk about economic inequality? Where are we talking about? What are talking about? When are we talking about? And how are we going to talk about it? This chapter addresses each of these questions.