The term middle class has evolved over time (you can read more about it here) and depending on your demographics, it could also mean differently than the rest of the world.
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From an economic point of view, the middle class affords a cozy existence. “Comfort came in with the middle classes,” wrote the British art critic Clive Bell. Economists define belonging to the middle class as enjoying a measure of discretionary income, above and beyond covering the basics of food, shelter, and education. Middle-class consumers take out mortgages to buy homes, purchase scores of convenient appliances, go on vacation, send their kids to good schools, and plan for retirement. In other words, being in the middle class meant being in a secure economic position, beyond living paycheck to paycheck–or at least it once meant that.
Defining the middle class by income may be convenient, but it can also blur the differences between, say, a nurse and a plumber, or a small business owner and an accountant, who can all be middle class yet have widely different educational backgrounds and careers. It’s a commonly held belief that a college education is a passport to the middle class. But there are many members of the middle class who lack a college education.