The surprising finding of this book is that, contrary to conventional wisdom, global income inequality is decreasing. Critics of globalization and others maintain that the spread of consumer capitalism is dramatically polarizing the worldwide distribution of income. But as the demographer Glenn Firebaugh carefully shows, income inequality for the world peaked in the late twentieth century and is now heading downward because of declining income inequality across nations. Furthermore, as income inequality declines across nations, it is rising within nations (though not as rapidly as it is declining across nations). Firebaugh claims that this historic transition represents a new geography of global income inequality in the twenty-first century. This book documents the new geography, describes its causes, and explains why other analysts have missed one of the defining features of our era—a transition in inequality that is reducing the importance of where a person is born in determining his or her future well-being.