One of the reasons I like costco actually 10% or so is a fine margin to pay.
Trouble is, how do you prevent them making stacks of companies compounding the 10% profits. And is 10% sufficient to build up a buffer for when hard times hit?
This thinking has been triggered by fuel producers and sellers making sky rocket profits because of the increased oil prices. The same as the overheated graphics cards.
To make a poor analogy to physics: if you measure something which changes when you change unit/frame of reference -- it's not a well-defined thing.
The best policies have the same effect regardless of the legal structure (within the policy) superimposed on the actual action.
Medium policies can be optimized/gamed (perspective) -- but are designed to be adversarial, in that the gamed outcome is at least OK but potentially in fact the desired one (for example -- if you tax land, then not paying the tax means not using up land, which may be a desired policy goal). These can cause issues, though -- common law is an adversarial system, and "justice" can usually be translated to "access to lawyers," imo.
The connection with the above is that while the solution used is probably not universal -- sometimes, the optimal solution is, so the adversarial policy is just an approximation of "good policy".
Bad policies not only don't compose -- but then bureaucrats go on and insert discretion to try to make them compose. On the surface, this often looks like common sense -- but the result is insiders can keep doing the Bad Thing, but you can't do anything which isn't the Way Things Are Done -- because you need approval, and it Looks Bad.
/rant
More heavily tax profit above a certain level? Allows for funnelling back some of the excessive profits. Suffers from the same tax evasion as we currently have where profits are skewed on the books with all kinds of accounting tricks.
Demanding sales prices cannot exceed cost + 10% of cost? In aggregate or per unit?
The drug industry is like this; the profits on a single drug sale are insane, even counting the R&D costs for that particular drug. However, those profits are offset by the losses incurred on all the other drug ideas that hadn't panned out despite the hundreds of millions of dollars invested in them.
The record and publishing industries are similar. As Steve Jobs once said, the main job of a music label isn't selling records, it's not even marketing or promotion, it's identifying artists with potential to be great hits amongst the thousands of wannabes. The revenue that labels get, and it's a lot of revenue, mostly goes towards recouping the costs of failed bets.
