In this, his final book, economist Anthony Atkinson, one of the world’s great social scientists and a pioneer in the study of poverty and inequality, offers an inspiring analysis of a central question: What is poverty and how much of it is there around the globe? The persistence of poverty—in rich and poor countries alike—is one of the most serious problems facing humanity. Better measurement of poverty is essential for raising awareness, motivating action, designing good policy, gauging progress, and holding political leaders accountable for meeting targets. To help make this possible, Atkinson provides a critically important examination of how poverty is—and should be—measured.