[hot_gril]

They don't get to choose. The only way to get above-market pay is to keep potential employees out who would otherwise be offering better price:performance. That's the goal of a union, but they'll represent it in different ways, sometimes less obvious than others.

[monknomo]

A union is made out of its members, a union's goals generally match what the majority of dues paying members want. There is no platonic union waiting in the wings. There are just groups of employees that could all work together to get things the mutually want.

[hot_gril]

They can't really do anything without an exclusivity deal or some other way to force employees to be part of the union. If they don't have such a deal yet, they're probably going to pretend it's not their goal.