Let's see how this works. Herder A

isn't entirely sure what Herder B is going to do.

If Herder B cooperates and I cooperate, thinks

Herder A, and we both cooperate, I'll get ten.

However if Herder B is going to cooperate and I defect, I get 11.

What's my best play following pure self-interest?

Cheat. 11 is better than 10.

Well, what if on the other hand, Herder B, in fact, defects?

If I cooperate,

I'll get the sucker's payoff. I'd be terribly worse off.

What if I defect? Well, if I defect, I would get 0.

Well, let me tell you, 0 isn't good, but it's better than minus 1.

So my best play, if in fact I think Herder B is going to defect, is also to defect.

The result is logically, following pure self-interest, Herder A will defect.

And using

the exact same logic, so will Herder B. They both will defect.

Getting payoffs of zero.

And what that reflects is that the commons has collapsed even though they

went into it with self-interest and full knowledge of a way to fix it.

This is not what Adams Smith predicted.

This is not the invisible hand giving us the best of all possible worlds.

It's giving us the

worst of all possible worlds. The back of the invisible hand.