The middle class refers to a class of people in the middle of a social hierarchy, often defined by occupation, income, education, or social status. The term has historically been associated with modernity,[1] capitalism and political debate.[2] Common definitions for the middle class range from the middle fifth of individuals on a nation's income ladder, to everyone but the poorest and wealthiest 20%.[3] Theories like "Paradox of Interest" use decile groups and wealth distribution data to determine the size and wealth share of the middle class.[4]
Terminology differs in the United States, where the term middle class describes people who in other countries would be described as working class.[citation needed] There has been significant global middle-class growth over time. In February 2009, The Economist asserted that over half of the world's population belonged to the middle class, as a result of rapid growth in emerging countries. It characterized the middle class as having a reasonable amount of discretionary income and defined it as beginning at the point where people have roughly a third of their income left for discretionary spending after paying for basic food and shelter.[5]