The IATSE (union for technical/artisan roles related to film/tv/audio/events/etc) created a training trust for their members in 2011 and, from what I've heard, it seems to be working pretty well. https://www.iatsetrainingtrust.org/ I'd love to see other unions take notes when their industries start to modernize. They do all of the standard OSHA training, etc, but also keep Lynda.com subscriptions for their members, reimburse group craft training organized by local chapters, and have developed some specific certificate programs for retraining into A/V roles from less technical ones.
One of the best things out of it though, is the free CPR/AED class, which many members have taken and has saved more than a few lives, that I know of personally.
I also regularly take advantage of Lynda.com, and we also have specialized classification training depending on what kind of work you are doing, be it special effects, welding, or aerial work. Out west, some of these classes are requirements for employment; the east is catching up
Each worker is hired based on skill -- that said, if you're a horrible person, you're not likely to get work, unless your skill is really above and beyond. The end result is a group of awesome people who do outstanding work.