On Monday, March 15, thousands of graduate student workers at Columbia University went on strike, refusing to teach, grade papers, or perform research until their contract demands were met by the university administration.

Columbia graduate workers have been organizing since 2014 to demand that the university recognize their union. Because Columbia is a private institution, unless the university voluntarily recognizes the union — which it has not — the ability of graduate workers to unionize is decided by the National Labor Relations Board (NLRB). In 2004, the Bush-era NLRB ruled that graduate workers at Brown University could not unionize, as they had “a predominately academic, rather than economic, relationship with their school.”

This debate — whether graduate workers are deemed to be students or employees — has been a defining issue for organizers at private universities for decades. But in 2016, the NLRB reversed its Brown decision after being petitioned by Columbia graduate workers. In a 3-1 ruling, the Obama-era NLRB affirmed the right of student workers at Columbia to organize: “The Board has the statutory authority to treat student assistants as statutory employees, where they perform work, at the direction of the university, for which they are compensated.”