A new Harris poll finds more than half of all residents in New Jersey and across the nation now consider themselves to be either lower middle class, or working class.

(Cheryl Casey, ThinkStock)

Three out of four respondents say they're facing significant financial difficulties, and one-third are losing sleep over it.

"Income levels have stagnated, while at the same time costs of higher education, property taxes housing costs and the like continue their inexorable rise," said economist James Hughes, Dean of the Edward J. Bloustein School of Planning and Public Policy at Rutgers University.

Hughes said many people "feel they're being overwhelmed by rising costs."

"The economy has not really generated significant income gains except for those in the top one percent or the top one tenth of one percent. People feel as if they're on a treadmill, it's really the great middle class economic squeeze," he said.

Hughes also said while the unemployment rate in both New Jersey and the nation have dropped, many people with jobs may only be working part-time, even though they'd rather have full-time positions.

"We have a much, much higher under-employed rate than unemployment rate," he said. "And that's making it tougher on many people.

Hughes believes this is probably part of a long-term transformation, "not simply a short-term blip. It's not simply a cyclical part of the business cycle."

He said the trend is being driven by the rise of information technology, which is leading to the loss of lower-skilled white-collar jobs. Globalization is also taking its toll - many of the jobs that might have been located here are done much more cheaply overseas.

"People feel trapped," Hughes said. "Their incomes are not increasing, however all the household and living expenses are increasing, they're worried about the future of their children, and the economy is not providing the appropriate jobs where they feel they can get ahead."