One more note on the subject. I don't like the American union system in that it's adversarial. To the worst degree. They don't fight for employees, they fight against the hiring entities. Often times, they are unreasonable about how much employees should get at the expense of the hiring entity.
Germany is different. They have a collaborative system where the two parties find middle ground. Companies want to work with unions to keep their employees happy, while unions want the companies they negotiate against to succeed so they never negotiate without trying to better the company they are negotiating against.