"It allows them to increase or reduce their workforce more easily, and in an uncertain environment, that can be very valuable to the firm," Houseman said.
More kinds of businesses seem to be drawing that conclusion, as industries not thought of as traditional temp work territory are using more contract workers. Hatton pointed out that adjunct college professors face much of the same uncertainty and lower wages than their full-time counterparts. And manufacturing companies make up around 40 percent of the current demand for temp workers, Houseman said.
"In the government data, you see that 17 percent of assembly line workers are hired through the staffing industry," Houseman said.
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With organized labor losing its clout, there's little to check companies' ability to shed workers the moment they perceive an economic chill, said Eileen Appelbaum, a senior economist at the Center for Economic and Policy Research. "In the private sector there's no counterbalancing power," she said. "The decisions are almost costless to them."
Appelbaum added that domestic outsourcing — when companies contract with third-party firms to handle everything from their janitorial to their payroll services needs — is on the rise.
It's all part of a broader shift to an everyone-for-themselves workforce, labor economists say. Business services firm MBO Partners says there were 17.7 million independent workers last year, up 10 percent from 2011.
Berchem called this shift in the labor market a "win-win" for companies as well as workers. "We've seen an increase in workers preferring flexibility," he said. "Family is a big priority for temporary and contract employees and they prefer the flexibility such work allows."
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Lynn Monaghan, 33, began temping after a transition away from her former career in event planning and says there are pros and cons.
"The pros are, it's given me a great amount of flexibility," she said of her current job, which is also nearby where she lives in suburban Boston. "Being a working mother, that has been really beneficial to me. There's less pressure," she said.
But flexibility is relative.
"There is certainly a small segment of the workforce ... that does want real flexibility in their lives. The thing is, though, that temp work is very flexible for employers and not that flexible for workers," Hatton said. "It gives them a profound sense of insecurity."
As a temp, even something as innocuous as personalizing a workstation can be a gamble. With her unemployment benefits exhausted and "no calls whatsoever," Dayton, Ohio-area resident Ronda Roberts said she took a temp job in December 2012 doing clerical work that paid a quarter of what she previously made as a developer of training materials. "I kind of felt like I didn't have a choice," said Roberts, 55.
A year later, even that rug was pulled out from under her. Roberts said she took a rare sick day, only to get a phone call from the temp agency that evening, telling her that her contract had been ended, effective immediately.
When she asked if she could retrieve her computer case and other personal items, the agency told her she wasn't allowed back into the office where she had worked for roughly a year, and that she had to wait for the company's corporate human resources department to contact her.