I don't think I missed your point. I think I said that a rational duopoly won't bother worrying about what economical solution best prevents a third entrant, wh

I don't think I missed your point. I think I said that a rational duopoly won't bother worrying about what economical solution best prevents a third entrant, when there is always the possibility of simply paying from established wealth to compensate a would-be entrant for their willingness to not enter. I don't see it as a political problem. It's such a ubiquitous part of any real market that I just see it was a way in which typical econ toy problems fail to correspond to reality and fail to produce useful predictions. It's like trying to use Newtonian physics when quantum effects really matter, except you've got so many economists employed because of the Newtonian-like toy models and they have a real need to keep hand waving and trying to convince everyone that the Newtonian approximations matter, that deriving theoretical results like this matter to "build intuition" or "create the mathematical framework" or whatever, but it's just clearly not true or useful to anyone but those researchers themselves.