The University of Calgary has a graduate student union, and it worked pretty well. Our minimum salary for teaching assistantship was pretty good. Health benefits were good. We were told quite clearly by the union that if we were asked to work more, to just tell them, and they would take care of it.<p>So the department never gave us more work than the maximum allowed by the agreement between the union and the university - in fact, usually they put 10-15 hours of leeway every semester, because they didn't want to be in breach of the contract.