[Hydraulix989]

> That's definitely untrue.

I think he meant Efficient Market Hypothesis, which could be posed as a strategy.

> That's also pretty untrue, or so pedantic as to be meaningless.

It's still collusion.

> You're really stuck applying Econ 101 in one of the worst places, retail.

This is Game Theory, not Econ 101. I also think it's one of the best places.

> But sellers on Amazon? C'mon man, sellers coordinate prices via implicit information exchange on Amazon in a way that, if they were allowed to, they would just collude straightforwardly to do so.

I've seen it happen. I've even seen collusion with online reviews on there.