MetaJess

Collective action problems and Covid: a thread.

Many people, rightly, point out that Covid is not just a matter of individual choice, because it is a negative externality. Mary's behaviour affects John whether he likes it or not, because he can catch the virus from her.

When it's too difficult for the affected parties to deal with each other, like when someone is polluting the air, you may need the state to get involved. That's an obvious reason you might want the govt to intervene to limit the spread of the coronavirus.

But there's another reason too: the difficulty of *collective action*. Collective action problems exist when everyone (or almost everyone) might want to do something, but they can't trust each other not to cheat. And for the agreement to work, it's all-or-nothing.

Sea fisheries are a real-life example of this. All fishermen would be better off if they could all agree not to catch too much cod, to keep stocks high. But they can't be sure other fishermen won't be greedy, so *all* have an incentive to overfish now while they still can.

This is a "tragedy of the commons". The prisoner's dilemma is another example - you cannot be sure the other guy won't snitch, so you better snitch too, even if you'd both be better off staying quiet. Imagine that game with a hundred prisoners where one snitch ruins you all.

Now: Covid. One proposal is to relax distancing measures and let people decide for themselves what they want to do. If you're over 60 and don't want to risk dying, you can self-isolate until the vaccine comes. Everyone else can go back to normal.