Something may be happening now, though -- after Luchkowsky and about 60 fellow factory workers joined a union and threatened to shut down the plant with a strike. He said his employer is now negotiating permanent contracts that would help give him what he’s looking for: “wage increases, benefits, paid time off and holidays -- all of that.”

Katz and Krueger’s research shows that among the alternative workforce, independent contractors are happiest with their lot -- 84 percent of them prefer working for themselves.

‘Bit of Anxiety’

“You make your own hours, you are your own boss, you don’t have to answer to anyone,” said Dina Scherer, 34, a wardrobe stylist and personal shopper for eight years. She finds some clients via the task-matching website Thumbtack and has also contracted to work for companies including American Express Co.

Scherer, who lives in New York, does acknowledge a downside: “You have to drum up your own business. You do hustle a lot. Sometimes you don’t know where your next job is coming from. It does bring a little bit of anxiety.”

Another group, on-call employees, are split fairly evenly on whether that status suits them. About three-quarters of temp workers hired via an agency would prefer a permanent job.

Katz and Krueger say more research is needed to pin down the causes of the shift, but they advance a few tentative explanations. It could be the impact of the Great Recession -- in which case the phenomenon might prove temporary. If technology is driving change, by making it easier and cheaper for companies to contract out tasks, it’ll be harder to roll back.

‘Tidal Wave’

Gene Zaino sees a combination of the two forces at play -- one that’s benefiting his business, MBO Partners. It handles back-office tasks for independent contractors, ranging from billing and collection to making sure taxes get paid. More than 50,000 use the service, typically people doing “knowledge work.”

“We were standing at a shoreline for many years, and all of a sudden a tidal wave hit,” he said. “Our services are in high demand.” Companies buffeted by the recession are less keen to make the long-term investment of hiring, he said, while technology can identify “a contract-talent workforce that’s easy for them to dip into and pull out of.”