We re-examine tacit collusion under a simple punishment rule in which firms match any lower price by their rivals, but otherwise leave their prices unchanged. We provide conditions under which this simple rule sustains collusion and is credible. Provided competition is imperfect, collusion can...

Tacit collusion is explored under a strategy in which, loosely speaking, firms match the lowest price set by any firm in the previous period. Conditions are provided under which this strategy supports collusive outcomes in a subgame perfect equilibrium. In contrast to traditional results, the...