When Robin Gary teaches her students at Elon University in North Carolina about poverty and social justice, she lets them know her knowledge stems in part from personal experience.

“I told my students I’m a professional woman with a master's degree who a lot of times is food insecure by the end of the month,’’ says Gary, an adjunct professor whose employment is contingent on classes needing an instructor, and the school deciding each year whether to renew her contract. “To be teaching a class on poverty and to be living the experience is ironic.’’

When members of the United Auto Workers took to the picket line a month ago in a strike against General Motors that resulted in a tentative deal Wednesday, securing better pay and benefits for temporary workers was a major focus of negotiations.

But the auto industry is hardly alone in its reliance on temporary employees. From the health care field to academia, temp workers are a growing segment of the American workforce, often earning lower pay and fewer, if any, benefits compared with colleagues in permanent positions.

While a temporary workforce can help boost the corporate bottom line, enabling businesses to cut costs and have more flexibility, it can be a bad deal for workers, according to labor experts, who say it holds back those people who want a permanent slot and are struggling to make ends meet, and those who have secured positions but believe they have less leverage to demand better wages in a changing jobs market.

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"Every assignment can end at any time and ... so that makes it even harder to stand up against unfair or unsafe working conditions,’’ says Laura Padin, senior staff attorney for the National Employment Law Project, which advocates for low-wage earners and those who are unemployed..

More broadly, "the constant threat of replacement by a temporary worker ... really degrades wages and working conditions for permanent employees as well,'' she says, "because they know if they ask for higher wages, if they try to unionize... they have to worry, 'Will I be replaced by cheaper labor, somebody doing the same job for less money?''

Small share of workforce can have big impact

The U.S. temporary staffing industry, which provides temporary workers to businesses, is growing, with revenue projected to increase 2% to $130.9 billion this year, according to Staffing Industry Analysts, which provides research and guidance to the sector.

In August, the preliminary estimate of jobs in the temporary help industry numbered 3,033,400, according to the Bureau of Labor Statistics. That was in comparison to 1,758,700 jobs in that category during the same month in 2009.

But that figure doesn't include the many temporary workers who are hired directly by businesses rather than through agencies. There is no official broader estimate of how many Americans hold temporary jobs, but their numbers include seasonal hires by retailers during the holiday season, and adjunct professors who are typically hired directly by colleges, but lack a track to tenure or a permanent position.

In 2017, 45% of instructional faculty at colleges nationwide were adjuncts, according to the Service Employees International Union.

That's in comparison to five decades ago, when more than 78% of college and university faculty had tenure or were on the tenure track, according to William Herbert, executive director of the National Center for the Study of Collective Bargaining in Higher Education and the Professions at Hunter College in New York.

By 2009, only 33% of faculty had those more secure positions, and "among non-tenure track faculty,'' Herbert says, "the fastest growth has been in the hiring of part-time teachers. It has led to a large pool of college teachers without job security, decent wages, and benefits.''

Meanwhile, in the auto industry, as much as 30% of the production line at some auto plants might be temporary workers, according to Susan Houseman, an economist with the W.E. UpJohn Institute for Employment Research.

When the UAW launched its first nationwide strike in 12 years last month, a key goal was to secure better treatment for temporary workers who often spent years working side by side with those who had permanent status. Unlike their colleagues, the temps earned only $15 to $19 an hour compared with legacy workers hired before 2007 who earned $32 an hour. Temps also could not participate in profit sharing, and had little time off or job security.

The union and GM reached a proposed tentative agreement on a new contract Wednesday. The strike is not over, as leadership weighs whether to submit it to members for ratification. But many of the demands in regards to temp workers were met.

They include full-time temp workers gaining a quickened path to permanent status starting in January, part-time temps having a route to regular status starting in 2021, and improved paid and unpaid time off.

Temp workers as a share of the overall job market remain small, with those specifically hired through temp agencies amounting to about 2%. And such positions can fill a vital need for those who simply need a paycheck, or who prefer flexible employment.

“The main reason workers take temporary jobs is as a bridge to permanent employment,’’ says Jon Osborne, vice president of strategic research for Staffing Industry Analysts, adding that lower-level temp positions in particular, in fields like clerical work, convert to permanent positions roughly 30% of the time.

Then there are those who simply prefer temporary jobs. Older workers may just want to supplement their income, while "higher-paid workers, particularly higher-paid health care workers, often see temping as a lifestyle,'' Osborne says, "working for several months, taking time off to travel… and then working again."

But temp positions can have a dampening effect on overall morale, and potentially wages as well, some labor experts say.

The Economic Policy Institute found in a March 2018 paper that the pay premium in manufacturing – defined as the extra compensation earned by a worker in that sector as compared to workers in other fields – had shrunk 3.9% from what it had been in the 1980s.

That was due in part to the growing number of lower-paid workers hired through staffing agencies, which rose to 11.3% in 2015 as compared to 2.3% in 1989, the institute said. But other manufacturing employees also saw their wages diminish.

The rising presence of temp workers "has an overall depressing effect on the wages because ... this allows employers to avoid the bargaining table,'' says Heidi Shierholz

director of policy at the Institute where she is also a senior economist.

Lower wages can hurt the overall economy, says Harley Shaiken, a professor at U.C. Berkeley who specializes in labor.

"The flip side of high wages is high purchasing power and that creates economic growth,'' he says.

Strikes, victories could change equation

The UAW's possible success, and other recent wins by labor, signal that workers might be gaining more power in their fight for better benefits and pay. That might impact temporary workers as well, some labor watchers believe.

Gary, who began teaching in 2011, says she has only been able to find adjunct positions because she lacks a doctorate. “I’d much rather be someplace and say ‘This is my job forever,' " she says, "but you kind of get stuck with what’s available.’’

She says that Elon, where she’s been since 2015, is “the best place I’ve ever taught.’’ She has health insurance because she currently has a full-year contract. She's also earning more than she has at other colleges. But being an adjunct “is very precarious and stressful.’’

“I always have in the back of my mind ... 'What am I going to do if they don’t give me a contract or if I don’t have enough classes to teach to pay my bills?' ’’ she says.

That was the scenario Gary dealt with in the spring. With no classes available for her to teach, she tapped retirement funds to pay her rent and car note, applied for unemployment benefits and found a temporary job that paid $13 an hour.

“Once my retirement funds ran out, I was trying to survive on $300 a week which absolutely didn’t pay the bills,’’ she says.

When Gary was a day away from being evicted, she reached out to the university, which gave her a loan and released her first paycheck for the new school year in August instead of September.’

Still, earning less than colleagues with permanent positions, she struggles.

At the end of the month, ’“I literally have no spare money to go to the grocery store to buy food,’’ she says.