I’ll let Chris Edwards commentary at CATO speak for itself:
Statistical studies find that unionized public sector workers earn a wage premium of about 10 percent over non-unionized public sector workers… employee compensation represents half of all state and local government spending. Aside from inflated wages, public sector unions have pushed for excessive pension benefit levels, which are creating a fiscal crisis for many governments…. Unions certainly have free speech rights to voice their opinions about public policy. But collective bargaining gives unions the exclusive right to speak for covered workers, many of whom may disagree with the views of the monopoly union. Thus, collective bargaining is inconsistent with the right to freedom of association.