The main difference between the UAW and a regular contracting firm is that if I decide to stop buying labour from a regular contracting firm, that firm can't an

The main difference between the UAW and a regular contracting firm is that if I decide to stop buying labour from a regular contracting firm, that firm can't and won't wind up blockading my factory entrance and trying to stop my new labourers getting in. Whereas if GM tried firing all its union employees and hiring non-union labour instead... well, I'm sure you can guess what would happen. If the UAW were a regular firm, it would be unobjectionable.