Long story very short, history. Unions in the US are organized shop by shop.
You can go to a union's homepage and click "JOIN TODAY!" if you wish. It just doesn't create any obligation for your employer to care.
You can go to a union's homepage and click "JOIN TODAY!" if you wish. It just doesn't create any obligation for your employer to care.
Not true for Norway, at least.
Edit: although I'm in tech I understand it covers everyone regardless of role