After doing a (very) cursory search, average dues are under $500/year and unionized employees have total comp that's almost 50% higher than nonunionized employees [1]. Total comp that's largely not taxed.
This data comes to us from the BLS via an organization whose homepage lists services such as "Counter Union Campaigns", "Union Avoidance", and "THE UNION-FREE PRIVILEGE®".
The part about dues sounds about right. doitwithoutdues.com was Amazon's anti-union propaganda, so they had every incentive (and looking at the website the shamelessness) to exaggerate union dues. Yet, the number they came up with was only $500 per year.
So to break even, a union has to cause wages to be higher than the non-union situation by 1%? That seems simple enough to do. I would be very surprised if the vast majority of unions don't earn their keep tenfold.
I worked for a company with two plants, one unionized and the other one not. For the same job, the unionized plant paid approximately 20% more than the non-unionized one for the same jobs. A 1% due rate would have been a steal of a deal.
My union dues are less than $50 per month, and it's one of the bigger/more powerful unions in the US. I don't agree with everything they do, but the pay, benefits, and security (very hard to be fired) don't have a non-union comp (that I'm aware of, anyway).
