Last week, the University of California at Santa Cruz administration fired more than 80 graduate student workers, including one of us.

The move was retaliation for a December strike in which graduate students who are paid teaching assistants withheld fall grades. We demanded a cost-of-living increase that would bring UC Santa Cruz graduate students out of “rent burden” — when 30 percent or more of one’s income goes toward rent and utilities.

Many of us pay more than 70 percent of our income toward rent, surveys found. In response to the grade withholding, the administration proposed a $2,500 additional annual stipend, which neither applied to all graduate students nor would relieve the rent-burden. On Feb. 10, hundreds of us took to the picket lines, canceling classes or holding them at the picket line, demanding an end to the administration’s stalling, intimidation and threats against graduate student workers protesting unfair wages.

The university’s harsh measures inspired sympathy strikes, walkouts and threats to withhold grades en masse on virtually every other UC campus. Sen. Bernie Sanders (I-Vt.) condemned what he called the university’s “disgraceful” act. But while UC Santa Cruz stands out for its severe tactics, the exploitation of graduate-student labor is endemic to higher education. We teach for poverty-level wages only to enter a dismal job market: Some 60 percent of university teaching jobs are off the tenure track, meaning they are typically part-time and lack benefits — yet still highly competitive. That’s why innumerable adjuncts are fighting here, too.

A burgeoning labor movement across the country is watching this fight as low wages and high living costs have defined many cities in the United States.

In Santa Cruz, a coastal town next to Silicon Valley, a one-bedroom apartment costs $2,600 per month on average, while most graduate students earn a base pay of $2,100 — for nine months. The university covers our tuition, and health care is provided through our United Auto Workers contract. The UAW has not approved our strike, calling it a “wildcat” action. Those of us who have been fired will have to figure out whether we can continue our studies without a paycheck or health insurance. International students are not sure they can remain in the country without a visa, which requires full-time student status. For them and us, the money we raise in our strike fund is our lifeline.

At UC Santa Cruz, as at most universities with PhD programs, graduate students “wear two hats,” as UC Santa Cruz’s director of labor relations wrote in an email, and this suits the university. We are “students” when officials want to deny us higher pay since teaching is considered part of our training as scholars, yet we also are “employees” who allow the school to fulfill its mission of teaching undergraduates. Our employment obligations conflict with our research and study time.

Teaching is a core responsibility for graduate students. We lead classroom discussions and grade papers and exams. We typically are the only people who read or engage with undergraduate work with depth. Teaching can be rewarding; in the fall, Rebekkah was teaching a course on the modernization of Paris and its effect on global literary movements — a course she designed herself and dreamed of teaching for years. Often courses we are assigned are unrelated to our field of study.

The challenge has been to teach, complete our coursework, conduct research and write dissertations without adequate compensation and taking on student loan debt. For us, there was an additional question: how to support our first child, due this month?

We find Santa Cruz’s stance on grades harsh since, until 2000, they did not exist on this campus, which has a tradition of “progressive” pedagogy. Soaring tuition necessitates grades, which serve as proof of the “product” of education. Undergraduates, we are told by the administration — at least implicitly — are harmed more by our grade strike than by student debt, which underwrites the contemporary university system.

Like other universities, UC Santa Cruz has raised its undergraduate enrollment, bringing in more tuition dollars and more graduate students to meet the demand.

The university does not advertise its business model to incoming graduate students. After pouring time, money, debt, energy and love into our degrees and projects, dropping out seemed unthinkable.

Paying teaching assistants a living wage is economic justice. The university appears dead set against showing weakness in the face of a vibrant labor movement. UC Santa Cruz administrators — and college officials across the country watching carefully — know how much the modern university depends on exploiting graduate teachers, during and after graduate school. The strike endangers its core business model.

After taking out student loans, getting second jobs, moving every year, living in shoe-box apartments and illegal units, negotiating with unscrupulous local landlords — sacrificing the chance to have a child was one we were unwilling to make. Though our pregnancy made the decision to strike all the more costly, we are not victims, and we know what it means to stand up to a major privatized-public institution such as the University of California. We are aware of the intense personal and collective risks involved. Yet the obvious choice was to strike, and we are not backing down.