How common is a Perfectly Discriminating Monopsonist in respect to labour rates? Or anything close to it?
Standard explanations show a normal supply curve for labour, and the marginal cost of that that setting the quantity of labour demanded. But surely the reality is that you don't generally have to increase wages to all employees? You can often invent a different part of the pay structure, or change the job in some very minor way. Eg you divide Burger Flippers into Junior and Senior Flippers, and pay them different rates.
From which my question: are there studies that look at this? Is my scenario one for which there is any evidence (either way, obviously).