Comment: First, for a monopoly to form

(See in situ)

In reply to comment: more scenarios (see in situ)

First, for a monopoly to form

First, for a monopoly to form all that's needed is for there to be disagreements between DROs of unequal strength *sometimes.* Not every dispute has to be that way.

Secondly, if the 20 are working together consistently, and thereby dominate the other(s), then they're a cartel. QED.

"Alas! I believe in the virtue of birds. And it only takes a feather for me to die laughing."