[_delirium]

> these sorts of alliances form accidentally and naturally

The airline-ticket market is kind of fascinating to watch from that perspective. On directly competing routes major carriers often end up with the same fares and matching each others' moves, but the exact process of who leads and who follows is complex. There is all kinds of informal signalling where companies attempt to figure out the others' intentions without directly colluding. For example, a company might trial a $50 fare increase in response to increasing costs, and hope others will match it. If others don't, they might be forced to roll back the increase to avoid losing market share, admitting the trial was unsuccessful. It's in effect an offer of, "hey everyone, I think we should raise prices $50 on this route, do you match?", followed by "ok, I guess not, retracting" if they don't, but not explicit.