“Even in this relatively simple price-fixing case, for example, competing briefs tell us (1) that potential treble-damage liability would help enforce widespread anti-price-fixing norms (through added deterrence) and (2) the opposite, namely that such liability would hinder antitrust enforcement (by reducing incentives to enter amnesty programs). Compare, e.g., Brief for Certain Professors of Economics as Amici Curiae 2–4 with Brief for United States as Amicus Curiae 19–21. How could a court seriously interested in resolving so empirical a matter—a matter potentially related to impact on foreign interests—do so simply and expeditiously?”

So if nothing else, at least he is consistent, right?

To be clear, I believe Justice Breyer is is making the argument that because a per se rule is easier to administrate - in part because we “cannot fairly expect judges and juries in such cases to apply complex economic criteria without making a considerable number of mistakes, which themselves may impose serious costs” - we should therefore keep the per se rule in place. I also disagree with Justice Breyer on the substance on this issue. I disagree, of course, that juries and judges cannot fairly be expected to apply complex economic criteria; and even if that were true, I do not believe that the costs would be so serious as to outweigh the benefits (I think the costs would be low in part because rule of reason cases are so hard to bring that few will be brought and the odds of mistakes being made are low).