Do you actually believe that someone like Julia Roberts or Tom Cruise is going to have the Screen Actors Guild negotiate their salary? No, SAG just sets a scale

Do you actually believe that someone like Julia Roberts or Tom Cruise is going to have the Screen Actors Guild negotiate their salary? No, SAG just sets a scale and people can be paid more than scale. The same goes for the various sports leagues where all the players are members of an a players' association of some sort. This sort of arrangement could very well work for developers.