Editor's note: The following story ran Oct. 20, 1991, on Day One of the nine-day "America: What went wrong?" series published in the Inquirer.

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Everyone has a definition of middle class. It is a term that conjures up varying images for sociologists and economists, politicians and ordinary folks.

In Washington, for example, it is often said that the top of the middle class is whatever salary is earned by members of Congress. Today that is $125,100 a year.

But that's more money than 97 percent of the households in America earn.

Similarly, many families that earn $80,000 in salaries a year consider themselves middle class. But that income actually puts them in the top 6 percent of American households that file income tax returns.

For the purpose of the accompanying series, "America: What went wrong?," The Inquirer has defined the heart of the middle class as those wage-earners who reported incomes between $20,000 and $50,000 on their tax returns last year. Median family income that year was $34,213 - meaning half of all Americans earned more, half earned less.

Such returns - filed both by individuals and families - numbered just under 34 million. They accounted for 35 percent of all tax returns.

A definition of an extended middle class might include all households with reported income between $15,000 and $75,000. While individuals or families in New York would be living in poverty if they earned $15,000, the same individuals or families could well achieve a middle-class lifestyle in, say, Sedalia, Mo.

Slightly under 10 million tax returns were filed by the $15,000-to- $20,000 income group. That represented 10 percent of all returns.

At the other end of the extended middle class are people earning $50,000 to $75,000.

A total of 9.2 million returns were filed by that income group, accounting for 10 percent of all returns.

Overall, 53.2 million individuals and families in the extended middle class - with income between $15,000 and $75,000 - filed tax returns, accounting for 55 percent of all returns.