I'd like to start a discussion on what kinds of things we as stage managers can do as disciplinarians. Many of us cannot hire and cannot fire. In the academic world, none of that hangs over the heads of your laborers.
As for the academic world, students are graded on the labor they do or don't perform. Some are even work study/scholarship and either don't get paid for hours they don't do or aren't offered a scholarship the next semester.
I establish or use the "producer's" rules right from first rehearsal so everyone is aware of the expectations. I also get with the director prior to rehearsals and establish a unified front in handling situations as they arise.
I have had to be the disciplinarian on professional shows: from reporting and recording late arrivals to calls as well as reporting alcohol consumption in the theatre dressing room (during the show by an actor) to the producer. This is a level of discipline that I felt needed to be addressed by managment. I also talk one on one to actors/crew/staff for offenses that don't need to involve mgmt right off the bat.