Unionization usually works when: 1) the workers in question are not easily replaced (for example, specialized skills or long training period before they become

Unionization usually works when: 1) the workers in question are not easily replaced (for example, specialized skills or long training period before they become productive) 2) the workers in question are not easily able to switch employers, so they need the protection of a union (instead of just switching employers whenever they are unhappy, such that they are normally happy) There are lots of professions which either do not meet condition 1 or do not meet condition 2. However, grad students would seem to be a classic example of a group ripe for unionization.