Not sure if "principle" is the best word, but I wanted to keep the post short. Better would be to say that it's against assumptions which make free markets at l

Not sure if "principle" is the best word, but I wanted to keep the post short. Better would be to say that it's against assumptions which make free markets at least theoretically efficient. The other response to you is correct, and on top of that: When you have discrimination, you're effectively making multiple different "equilibria" on the demand curve (instead of one intersection with supply curve). Once you admit multiple equilibria, all the bets about efficiency (and also fairness) are off. Alternatively you can look at it as follows: The free market can be characterized by existence of market price, on which the participants converge... If you have discrimination, they won't converge on market price and so you don't really have free market (free as in speech). > Due to one time expenses, some kinds of goods cannot exist without discriminatory pricing. I don't think it's true. Linux does exist, for instance.