Alongside other elite universities and colleges, Yale filed an amicus brief on Monday to the National Labor Relations Board to argue against a pending Columbia University case on graduate student unionization.

The Columbia case, along with a similar one involving New School graduate students, could permit graduate students to bargain as employees of their universities and form unions. If the board rules in favor of the graduate students, this would overturn a 2004 legal precedent in which the board ruled that Brown University graduate students were students, not employees.

All Ivy League institutions, except for Columbia, collectively filed the brief with NLRB case between Columbia and its graduate student employees. An amicus, or friend of the court brief, can be filed with a court by any interested party.

“There is no compelling reason to reject the Brown decision,” the university joint-brief said. “There is no empirical evidence suggesting that [the Brown case] was wrongly decided.”

Not only did the brief argue that the Brown case should be upheld in the pending Columbia case, but it said that overturning the 2004 ruling would “impermissibly intrude” onto any school’s academic freedom.

Graduate student bargaining power has the potential to create burdening and disruptive effects on students’ education, according to the brief. The schools’ brief also urged the NLRB to recognize graduate students the same way it already recognizes masters and undergraduate students. The same should be held true for students doing research toward a PhD, the brief said, pushing back on the “false dichotomy between working and learning.”

Some graduate students at public universities have already unionized, where the brief acknowledged graduate students often earn very little money for their work. But a model of employment does not apply to a private school like Yale, where graduate students are often compensated through teaching stipends. Every Ph.D. student at Yale is guaranteed, until their fifth year, a full tuition fellowship of $38,700 in addition to a minimum teaching stipend of $29.000.

The brief addressed the fact that many graduate students work sporadically, stopping and starting work at different periods of their education. While previous cases have argued that these students should be guaranteed consistent employment by their schools, the brief argued back that such intermittent work is natural for graduate students, and there is a “clear expectation that they will not continue in their roles, either because they will graduate, a course will end, or for any of a myriad of other reasons.”

Universities, graduate student unionization movements and educational organizations have been paying close attention to the ongoing cases, and the joint brief by the nine universities is only one of several amicus briefs that have been submitted to the board. In fact, the American Association of University Professors filed an independent amicus brief earlier today that argued in support of graduate student unionization—a stance opposite to that taken by the nine universities.

In its amicus brief, the AAUP argued that graduate assistants are employees with collective bargaining rights and that this right promotes academic freedom, rather than harming faculty-student mentoring relationships.