Well, not exactly, Dr Sowell. You see, the rules are made and agreed upon by the union and the employers. There's a contract signed by both sides.
When I was a kid, I worked in a paper plate factory. One of the rules was, the machinist did not sweep up after himself. A laborer, paid half as much as the machinist, did the clean up work. The problem came when the machinist didn't have any work and the laborers were to busy elsewhere. The company wanted to change the rule and the union drove a hard bargain. It was a tough sticking point. Although the specifics were never public at the time, charges and counter-charges flew. The point is, don't get caught up in the haggling. Some companies and some unions are lousy negotiators.