America's middle class isn't what it used to be.
The share of Americans who are considered in that group shrank from 1991 to 2010, according to a new report from the Pew Research Center that covers this 20-year period. At the beginning of the 1990s, 62 percent of Americans qualified for middle-class status, a share that had dropped to 59 percent two decades later.
Even though everyone likes to consider themselves middle class, America has always been a socially and economically stratified society. Recent economic trends are creating even greater divides between the classes, such as the fast income growth among America's top earners. That's pushing more people out of the middle class because their incomes are too high for that category.
"The shift out of the middle class is a sign of economic progress, irrespective of changes in household incomes overall," Pew said in its report. "This is because the outward shift is accompanied by a move up the income ladder, into the upper-income tier, in all countries with a shrinking middle class."
Other countries experiencing shrinking middle classes during the same period include seven of Western Europe's 11 countries, including Germany, Finland, Denmark and Spain. The middle class grew in only four Western countries Pew surveyed: the Netherlands, France, Ireland and the U.K.
What does it mean to be in the middle class? Some would say it's a state of mind, but Pew considers it to include households with between two-thirds to double the national median disposable household income.
On the flip side, some Americans are falling out of the middle class due to stagnant or falling income, as well as increased income volatility. About one-third of middle-income Americans spend at least one month of the year in poverty, the U.S. Financial Diaries found in a recent groundbreaking study about the financial stresses mid- and low-income Americans feel.
The country with the largest middle class is Denmark, where eight out of 10 households fall into the category.
Read on about the indicators that may show whether you're no longer middle class.