> This is the nature of union employment: seniority >> everything else. Actors, writers, and directors are in unions in Hollywood, and the seniority plays no p

> This is the nature of union employment: seniority >> everything else. Actors, writers, and directors are in unions in Hollywood, and the seniority plays no part in who gets which part or which crew is hired for a production. Seniority has often been used in factories because it was easy metric where you had 'interchangeable' people doing the labour: the people were treated almost like machines/widgets themselves. But the advantage of seniority in that context was that it helped stability: you stayed at the same company so it reduced retraining / rehiring costs to the company, and in exchange for your loyalty to the company, the company was loyal to folks that didn't jump around constantly looking for greener pastures. But there is nothing inherit in being unionized that mandates the use of seniority as a metric.