Pew study sees a shrinking middle class in major US cities

A widening wealth gap is moving more households into either higher- or lower-income groups in major metro areas, with fewer remaining in the middle, according to a report released Wednesday by the Pew Research Center.

In nearly one-quarter of metro areas, middle-class adults no longer make up a majority, the Pew analysis found.

Pew defines the middle class as households with incomes between two-thirds of median income and twice the median, adjusted for household size and the local cost of living.

By Pew's definition, a three-person household was middle class in 2014 if its annual income fell between $42,000 and $125,000.

"The shrinking of the American middle class is a pervasive phenomenon," said Rakesh Kochhar, associate research director for Pew and the lead author of the report.

The squeezing of the middle class has animated this year's presidential campaign, lifting the insurgent candidacies of Donald Trump and Bernie Sanders.

Many experts warn that widening income inequality may slow economic growth and make social mobility more difficult.

Academic research has found that compared with children in more economically mixed communities, children raised in predominantly lower-income neighborhoods are less likely to move into the middle class.

Eight years ago, he was earning $28 an hour as a factory worker for Detroit's American Axle and Manufacturing Holdings, assembling axles for pickup trucks and SUVs.