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.

Many negative externalities can be addressed privately.

In Manhattan, a tower was going to block the view of some loft owners. So the loft owners paid the developer $11m not to build there. Ronald Coase, who won the Nobel for this, would be proud. https://www.nytimes.com/2019/07/22/nyregion/manhattan-real-estate-views-air-rights.html

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.

Sounds nice, except for the 12m+ people who would be self-isolating for months, with an increased risk of death anyway since (as we saw with care homes) true isolation is really, really hard to achieve.

But anyway - it also ignores the collective action problem.

*Everyone* is worse off in this scenario than in another where the virus is suppressed altogether, just like the fishermen: getting Covid sucks even if you don't die, and may cause permanent organ damage, we don't know. And nobody wants their older loved ones to die.

So, in this "individual choice" scenario, we have a tragedy of the commons.

Most of us would be willing to distance from others, if we knew *they* would do the same.

But how do we agree to that privately, knowing that *everyone* would need to sign up for it to work?

In this case, since it requires the whole country to sign up, we can't. It's a collective action problem. So we need the state to step in and enforce those rules, like it enforces fishing quotas to prevent overfishing.

These rules might be things that *everyone* would sign up to, in principle. In that case it's really a no-lose situation. A ban on private ownership of nuclear weapons may be an example of this.

In reality, some people do object. That's where democracy is needed to weigh up their wishes against other people's, to see which group is bigger - the ones who want these rules, or the ones who want to take their chances and let others self-isolate.

As it turns out, a huge majority of the UK favours the distancing rules the govt has put in place. 78% support the new rules, inc 45% who want the govt to go even further. Only 17% oppose them. https://yougov.co.uk/topics/politics/articles-reports/2020/09/23/brits-support-new-lockdown-rules-many-think-they-d

It's your right to disagree, of course.

But it is not a matter of individual action, but *collective action*. An alternative state of affairs that gives the 17% their way means the 78% *cannot* have their way. It's all-or-nothing.

To summarise: When a disease is invisible, infectious and lethal, individual action is not enough. You cannot escape the need for a *collective* decision on Covid. And, in the UK at least, most people want to avoid catching Covid, and avoid their relatives dying of it.

/end

PS: Elinor Ostrom won the Nobel Prize for studying ways that communities solve collective action problems without the the state. When it comes to fisheries, policing, etc, it's fascinating - but it's a slow, emergent process that works best in small communities.