It is important to note that this decision originated outside the University. While Columbia made the laudable decision to implement the Department of Labor standards that the raise is based on, it was the UAW who helped lead the charge to ensure that postdocs would be included in the final standard.
Despite Columbia’s implementation of this new salary minimum, no organization is responsible for ensuring that all departments have complied with the new salaries and that each postdoc is being paid the required salary. A postdoc union would be able to ensure that every postdoc is being paid at the correct rate and would also have a structure in place to address any grievances arising from underpayment.
In addition, a postdoc union could bargain for guaranteed annual wage increases and much more than wage increases. Unions typically bargain for contractually-guaranteed benefits and protections such as paid parental leave, childcare, job security, protection from discrimination, career development support, protection from sexual harassment, and more.