Students across the country, including the Student Labor Action Movement (SLAM) at New York University, are demanding higher wages on campus.

Over the past few years, thousands of students have waved picket signs and chanted slogans in support of raising the minimum wage for people who toil in fast-food restaurants and other low-paid professions. Now that advocacy has expanded to another class of worker: college-goers themselves.

Students at nearly 20 schools, including the University of Maryland at College Park, Columbia University, Northeastern University and San Francisco State University, are mounting campaigns demanding better pay for part-time work. The University of Washington's recent decision to raise its wage floor to $15 an hour has encouraged student leaders elsewhere — but many are running into administrators reluctant to fatten payrolls as they struggle to contain costs.

[It's not just fast food: The fight for $15 is for everyone now]

The campaigns are largely independent of national labor organizations, such as the union-backed Fight for $15 movement that has helped boost minimum wages in a number of cities, but they share the aim of providing workers with enough to pay the bills.

"Students are inspired by fast-food workers speaking out, home-care workers speaking out, their adjunct professors speaking out," said Beth Huang, a coordinator for the Student Labor Action Project (SLAP), an initiative of a labor union and foundation-funded group called Jobs with Justice. "Tuition, housing, textbooks are increasing in price while student wages have largely stayed stagnant."

The call for higher wages also comes at a time when many students who provide services for schools, such as graduate student teaching assistants and student athletes, have pushed to unionize -- with varying degrees of success. Previously, undergraduate student activism had focused more on improving conditions for campus staff.

"Students don't think of themselves as workers, even when they're working two part-time jobs to stave off mounting debt," said freelance writer George Joseph, who helped found a student group at Columbia University that is pushing the administration to raise wages to at least $15 an hour. "So I think that's part of the campaign, making students realize the value of their labor."

Forty percent of undergraduates attending college full time were employed in 2013, mostly in part-time jobs requiring less than 34 hours a week of work, according to the latest data from the National Center for Education Statistics. Just 8 percent of students work on campus, either directly for the school or through the federal work-study program.

The work-study program employs needy students through a cost-sharing agreement between the government and colleges. Those jobs must at the very least pay the federal minimum wage of $7.25 an hour, but colleges have the option to pay more.

And that's what the University of Washington plans to do, agreeing in September to raise the minimum wage for students and all other campus workers to $15 an hour by January 2017. The decision arrived after months of student protests to get the state school to comply with Seattle's new minimum wage law.

[With victory in L.A., the $15 minimum wage fight goes national]

Initially, the university only increased the wages of 70 of its lowest-paid employees, excluding 2,600 student employees making less than $11 an hour. But the school eventually relented and chose to follow Seattle's gradual pay increase for all workers.

"We want to pay our people as well as we can pay them," said Norman G. Arkans, a spokesman for the University of Washington. "We did the analytics, figured out the cost impact and decided this was in the interest of our staff and student workers. We didn't want to be out of step with the rest of the city."

Moving workers to $15 an hour in 2017 will cost the university an estimated $7.9 million, with $6.7 million of that for student workers.

Because federal work study dollars are awarded based on need, the total amount of money students working those jobs earn will not go up. Say for instance a student is awarded $3,000 for the school year. Instead of having to work 300 hours at $10 an hour to fulfill the requirement, the student could work 200 hours at $15 an hour.

"In a way, this gives students the advantage of spending more time studying, not working," Arkans said.

The students at Columbia University say they would also like to see work study money applied to a wider range of jobs, such as unpaid off-campus internships or time-intensive extracurricular activities, which could help them advance their career goals more than stamping books at the library.

"We do not have the time or money to access the same academic, extracurricular, and professional opportunities as other students," reads a petition the students are circulating. "It is unacceptable that any student should be forced to choose between academic success and survival." Columbia spokesman Robert Hornsby declined to comment on the campaign.

Students at the University of Maryland are using a similar approach to those in Seattle to get the college to increase wages, arguing that the school should comply with Prince George's County's new $11.50 minimum wage.

"We're only asking the school to do what the county has done for its workers," said Homa Hajarian, co-president of Maryland's student chapter of SLAP. "When it comes to a point where you can't afford to pay your rent and can't afford to eat, there is something wrong with the system. It's a problem that full-time students are working these jobs and still can't afford what they need."

Between penning essays on Aimé Cesaire's "A Tempest" and studying for comparative lit, Hajarian, 19, holds down two jobs at the University of Maryland.

Mondays and Wednesdays, the English major mentors elementary school children through America Reads America Counts, a work-study job that pays $10 an hour. Mondays and Fridays, Hajarian re-shelves returned books at the McKeldin Library on campus for $8.25 an hour.

The grants and scholarships she receives cover a majority of the cost of attendance, but the money does not stretch far enough to pay for the medication she needs. Getting one job off campus could mean more money but also more hours working, more hours not studying.

[How much a college student can earn from a summer job without losing financial aid]

"It's really frustrating when you come to a point where you can't do anything else to make more money, but you need more money," Hajarian said. "I'm falling behind in school work. Because I work during the day and also have class during the day, when I come home I'm exhausted."

Officials at the university say that because it is a state institution the school is under no obligation to comply with the county's minimum-wage law. That law requires local employers to increase hourly wages each Oct 1. for several years: $8.40 in 2014, $9.55 in 2015, $10.75 in 2016 and $11.50 in 2017.

Students met with university administrators in the spring, at which time the school agreed to study the costs of bumping its $8.25 minimum wage up to $8.40. By the school's own estimate, it would cost $220,000 to increase pay for the 8,000 students who work on campus.

"That's a total drop in the bucket for a giant research institution like Maryland," said Huang, who is working with the student organizers at Maryland.

Carlo Colella, vice president for administration and finance at the University of Maryland, said the school cannot afford the raise at a time when the state is cutting funding. Gov. Larry Hogan (R) is proposing the University System of Maryland reduce spending by $25 million as part of a broader effort to plug an estimated $1.7 billion deficit over the next four years.

"We respect the students' advocacy for their cause and welcome further dialogue," Colella said. "But we are in an environment where our resources are constrained. If we keep the current wage rate, we can employ more undergrads part time, but if we increase it then we'd have to tell some students we can't afford to employ them."

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