Everyone comes up against the 80:20 law at some time or another. It’s a rule of thumb that tries to capture the idea that what is important isn’t very numerous.
In many businesses, most sales come from a few customers. That sort of thing. It’s rarely literally true: the actual numbers vary all the time but the lesson is often both apposite and wise: don’t sweat the small stuff, focus on the few things that really matter.
The scientific debate over how the virus is spread is critically important for the economic debate over the speed and manner of lifting the lockdown.
‘Test, trace and quarantine’ appears to be a near consensus strategy. It is popular again in the UK, albeit after its adoption, abandonment and now re-adoption by the authorities. It’s a strategy that shows signs of working in countries that have tried it but remains controversial in countries that haven’t, notably the United States but also elsewhere.
Draconian regime
In the US there is a view that officials have neither the will nor the power to implement a sufficiently comprehensive – draconian – test and isolate regime.
It might be just cultural: protestors carrying automatic weapons and placards equating the lockdown with communism hint at the difficulties of enforcing any future quarantine.
These problems suggest the US needs to think differently, perhaps with some lessons for the rest of us.
While having no sympathy for gun-carrying lockdown protestors it is still reasonable to point out that shutting down the economy until a vaccine is found is not a viable strategy.
Creating an economic wasteland would carry human costs: eventually, a cruel and ghastly calculus has to be conducted: the economic costs versus lives saved.
While no economist would disagree with the necessity of a short-term lockdown there is less than universal agreement over what ‘short term’ actually means.
It’s obvious to everybody that some sort of economic and social reopening must happen relatively soon.
Transmission mechanism
John Cochrane, economist and senior fellow at Stanford University, considers all of this along with some early evidence about the transmission mechanism of the virus.
That evidence suggests that one of the principal means whereby one person infects another is via large droplets.
It should be stressed that the evidence is only tentative. But there is evidence: I found this in an end-March World Health Organisation report: “According to current evidence, Covid-19 virus is primarily transmitted between people through respiratory droplets and contact routes. In an analysis of 75,465 Covid-19 cases in China, airborne transmission was not reported.” Cochrane refers us to other research looking at this in similar ways.
Activities
The point of all of this is to come up with lists of activities that, after lifting the lockdown, should be banned or restricted. And activities, hopefully GDP-rich, that we can allow. Figure out, as best we can, the 20 per cent or so of activities that cause 80 per cent of the problems.
Sure, if we can immediately identify, via testing, each case of coronavirus when it occurs and then isolate each patient for 14 days, the virus will eventually die out. The alternative is a ‘good enough’, but workable, strategy versus one that strives for perfection but is impractical, at least in some jurisdictions. Or maybe consider both strategies simultaneously.
Why is that transmission evidence so important? It suggests that walking past somebody in a park is a low-risk activity unless that person is both infected and coughs or sneezes straight at you. Or you come into physical contact with them. It suggests that high value-added economic activity can resume with appropriate social distancing measures.
Cochrane points us to a fascinating essay by Jonathan Kay about coronavirus ‘super spreaders’. Kay talks about ‘Flugge droplets’, named after the scientist who, in 1899, discovered that microbes are mostly transmitted via large droplets expelled from the mouth or nose at high velocity.
Kay acknowledges that we don’t have enough data to be definitive but there is more than a hint of ‘super-spreader events’ (SSEs) that have created clusters of the virus, consistent with the idea that merely talking to somebody, at a distance, is a low risk event.
Proximity
Rather, being in close proximity – touching – in a crowded, confined space where people are shouting, coughing and sneezing is a recipe for potential disaster. Think après-ski bars and some care homes. Weddings, funerals and parties of all kinds are a no-no. Being indoors at a crowded social event seems to be a high-risk activity.
Kay reports his astonishment at how few activities account for so many SSEs. Of the 54 SSE events that he investigates, nine were associated with religious gatherings. 19 were either parties or other booze-filled events, five were funerals. six were face-to-face business networking events – ‘leadership’ meetings, for instance.
Once one individual attends more than one of these events we can observe strong network effects. University classrooms and ‘white-collar cubicle farms’ do not appear to generate SSEs.
We risk an SSE “whenever people are up in each other’s faces, laughing, shouting, cheering, sobbing, greeting and praying”.
I draw two lessons from all this. First, Kay’s work needs to be built on with more data and replication. Second, why not apply the lessons as well as a testing, tracing, quarantine regime?
As Cochrane says, banning parties isn’t very human but doesn’t carry much of a GDP cost.
