[the_bear]

I'll admit I'm not very knowledgeable about the logistics of unions, but I imagine there's some kind of up-front legal overhead. Like, maybe there are contracts between the union and the company, or within the union itself to determine how it's governed? I also get the impression there is some overhead in an ongoing basis in the form of extra meetings, more complicated negotiations, etc.

All of those things seem like relatively minor costs when spread out across a large employee base, but I could see it being prohibitive for a smaller company. Or maybe this is a solved problem and you can just find some boilerplate stuff online that takes care of the whole process.

[StudentStuff]

It seems your mis-understanding what a union is, the union will talk with management, forming an agreement as to what the pay scales are, how much paid leave is given at minimum, and escalation processes like grieving an issue when management does shitty things to the workers.

The "overhead" you speak of is to pay someone to negotiate on the workers behalf, save up for a strike stipend, and provide worker training (usually Unions will run or subsidize courses to help workers skill up, get licensed, etc).

[solidasparagus]

And now you have a fixed payscale that could easily make it harder to hire.

[pjc50]

There is as much overhead as people want there to be.

That is, so long as the employees are content, it will be very low; try to do things that they don't like and the cost will go up.