And as to agreements and price fixing — Sure, liability is very easy to prove if (1) the defendant concedes that he did conspire with competitors ; or (2) the plaintiff has uncovered evidence showing unmistakably that agreements were made in restraint of trade. But I imagine that most of the time these agreements and conspiracies will have to be inferred — meaning that there is no hard evidence.
Isn’t at that point where the “conscious parallel conduct” test comes in? And if so, how, exactly, do you use that test? Show me two firms that behave in exactly the same (parallel) way???

And, as I said to my Professor, I think Antitrust itself (as a body of law) is built on a faulty premise. The very theory of Antitrust suggests that these firms are masters of their fate — that they can price how they want and/or behave as competitively or anti-competitive as they want. Believe me, that is not how things work in the real world. No firm EVER prices according to cost, although I am sure that they would like to. God, that would make things much easier. But no. Firms have to incur costs — which, admittedly, are certain — OVER LONG PERIODS OF TIME involving periods of production before the final products will be available for purchase. Who knows what their products will be worth in the future? To suggest that the value of these finished goods are somehow dependent upon the costs the firms incurred in producing them is just plain silly. Business in the real world is just one dark hole, and every move is a gamble.

Okay, so now the question is: Do we bring the claim under a horizontal price fixing charge or a monopolization charge? Which is easier to show?

It seems to me that you will NEVER be able to show a horizontal price fixing agreement, because the test is “conscious parallel conduct,” and I doubt conspiring business ever behave in exactly the same way. So, how do you ever INFER conspiracies in restraint of trade? I asked this question to my professor (a blogger here), and he didn’t really have an answer.

Now, the monopolization question is a bit trickier, because you have to define the market before you can determine whether the defendant is guilty of monopolization. My impression is that Antitrust law doesn’t really have a sophisticated model for determining what is the relevant market — I remember that even Hovenkamp’s treatise faltered a bit on this point — does the relevant market include firms that could enter but have not yet? And does it include firms that are not even in existence yet? IF these two answers are yes, then it seems to me that there is really no way you can ever determine what is “the relevant market.” I remember asking the same Professor, if a firm prices above cost, and is thus guilty of monopolization, then the number of potential firms could be infinite, right? He didn’t really know how to respond.

So, all of this talk about rule of reason analysis sounds nice, but when it comes down to it, it seems to me, Antitrust Law has no real way to (1) prove price fixing ; or (2) define the relevant market.