Tonight’s lesson with The Girl was the Tragedy of the Commons.
I went over the basics: the theory goes that, in a field where villagers graze their sheep, each villager must be very careful not to graze more than their share. It’s very easy for one to graze just a little more, you see -- and have his sheep get just a little fatter, and get just a little richer. What would happen then?
“The others would get jealous?” The Girl said.
That can happen, I said – or they would fall behind if they didn’t graze just a little more too. Everybody would have to graze a little more just to keep pace with everyone else.
The Girl’s face brightened in recognition. “The Red Queen!” she said.
Excellent, I said – well done. Yes, it could be a runaway race to graze more and more, and after all, the commons belongs to them, because it belongs to everyone. But if everyone does that, I told her, soon there’s nothing left for anyone to use. It’s like the Prisoner’s Dilemma, in a way.
We talked about some examples – people who cut trees from the forest, or fish the seas. Each time, I said, they are only taking a tiny bit more – the problem is when everyone takes a tiny bit more.
“Didn’t they used to just dip buckets into the sea and they came up full of fish?” The Girl remembered.
Yes, I think that was John Cabot, I said, talking about the Grand Banks. When people pollute the air with smokestacks, I said, it works the same way.
“How?” asked The Girl, puzzled.
Well, I said, would you have a stack gush smoke into this room?
“Of course not!” she said, smiling.
But people pollute into the air, it belongs to everyone, so it gets to be someone else’s problem.
“I understand …” The Girl said sadly, and then brightened. “OOH! But what if the people in the often-coughing country next door get a fleet of giant fans?”
Ah, I said, recognising the game we often play -- but how will you power the fans? They need electricity, and that needs more smokestacks.
You’d need a battery factory for that, I said, and charge them, and that also burns energy.
“What if we buy them at the store?” she asked, already knowing the answer.
Then someone else has to make them, I said.
“Then it’s someone else’s problem!” she said, and we chuckled together.
“But Daddy,” she said, more seriously, “Is it always like that? Because then everything will be gone soon.”
I’m glad you asked, I said. A lot of people on the television think that people should never share anything in common, because it will always create a tragedy of the commons. But we have something they don’t have.
“What’s that?” she asked.
A Commons, I said -- a real one near us, where everyone grazes their sheep. People here say they’ve been grazing sheep on it since Roman times, and it’s still there. The people who live around it seem to be always arguing and working out some new agreement, but they always work something out.
“Why are they different?” she asked.
They know each other, and they know the limits and the consequences, I said. And no one ever told them that working something out was impossible.