In the collusion game, we found that collusion was only
sustainable in the infinite horizon repeated game. One Nash
Equilbrium of that game can be found when all players play a “grim
trigger” strategy, where they collude until an opponent chooses to
compete, and then compete for all future rounds as a punishment. In
such a game, if the one period bonus that comes from competing is
low enough, firms always collude and the punishment is never
triggered.
However, let’s...