[ETA: apparently my actual question got completely lost in translation. Thanks to the people who tried to answer. I think it has something to do with having said "libertarians" when my question isn't really about libertarianism.]
[Disclaimer: this post was written hastily and barely edited.]
I don't get how anyone things employer-employee relations are supposed to work. Libertariants have some opinions.
I think the idea is, we have no minimum wages, no mandatory unions, etc.; and then employers and workers bargain over wages by making offers to hire or be hired at a given wage. If workers employed by a firm F are unhappy with their wages, then some other firm F' could poach them by offering higher wages. Since F is afraid of that, F will have already offered higher wages.
But like, how does bargaining work? It seems like there's all sorts of parameters that might make a really big difference to the outcome of a negotiation like this, and I don't have clarity on what those are and how they affect the outcome. Do other people have opinions about employer-worker based on beliefs about those questions, or what?
[Some more disorganized thoughts follow, but the above is the basic question.]
Humans need a steady stream of food and shelter, or they become less productive (often permanently). That means that if the boss Bob has enough wealth to outlast his worker's stores of nutrients, he can basically pay them just the absolute minimum so that they can still work.
An argument goes like: the minimum wage law only harms people. If you remove the law, then more trades would happen, which are always good (or good in expectation, or in aggregate across a given class of people, or something) for both parties. But this just seems false? Without the minimum wage law, lots of people would probably be paid significantly less. Or maybe that's untrue? If it is true, it seems like there's an attractor where managers have all the wealth, and everyone else is paid just enough to keep them able to work. That's supposed to be not an attractor, because a slightly more generous manager could easily poach employees. But how does that break the equilibrium? Seems like the generous manager is just losing a bit of money. They could have their pick of employees; is that supposed to be a crux of the argument? That seems to just imply an exploitative equilibrium, but with more desirable workers getting a slightly better but still exploitative deal. (Exploitative, meaning that the managers are actively trying to keep the workers desperate for their next paycheck.)
Maybe I'm confused about the equilibrium reasoning because there's two "forces" pushing in opposite directions: a manager wants to threaten employees with lowering wages, and threaten other managers with raising wages (hence poaching the best workers). Is there standard wisdom about how these things are supposed to play out, e.g. with an evolutionary equilibrium model?
It seems like unions and minimum wages are a form of bargaining, using the government as a way to overcome coordination problems given the cognitive costs of doing distributed game theory. Why isn't that considered by libertarians to be a legitimate (i.e., reasonably endorsed as part of a globally coherent notion of justice) form of bargaining / decision-making? Is it about the use of government force? But don't libertarians endorse private property rights and other rights, which are also enforced by collective agreement?