The government of California has ordered all 40 million of its citizens to stay home. Schools are closed. Universities are closed. Most business are closed, and many will never open again. Will this extreme response stop the spread of the novel Coronavirus?
Consider Santa Clara Country, with total cases shown in the graphic below (credit to Dylan Grosz at The Stanford Daily for tracking this daily). It may be too early to say conclusively that extreme social distancing has failed, but the fact that public schools were ordered shut down on Friday, March 13, well, the cases have quadrupled since then. Is that due to better testing & identification of coronavirus? I don’t know, but I think this week that will be the main conversation.
Look, it is possible that Covid-19 can be stopped. Nobody knows the answer. But even if *The Shutdown* stops the virus, it is probably a cure worse than the disease because of the catastrophic economic damage. Even the most extreme measures will only slow it down, or flatten the curve.
Everyone seems to think South Korea “stopped” the virus. Maybe. They continue to see many new cases a day there. Here are reasons to be skeptical that Covid-19 can be flat-out stopped:
- Covert contagion. Research suggest the disease is spreading very aggressively among people with no symptoms at all. That asymptotic rate could be as high as 50% according to research cited in Nature. “Taking the results from several studies into account, Chowell thinks that asymptomatic or mild cases combined represent about 40–50% of all infections.” Sorry, guys, but when half of the people with a disease show no signs of having the disease, then the spread cannot be stopped and barely even slowed. I think of this as the invisible fire.
- Everywhere Already. Covid-19 is in all 50 states right now. It also seems to have spread to every country in Africa and Asia and the Middle East. Europe cannot stop it. It’s in Stockholm, Rome, Prague, and Berlin. It’s in Ireland and Iceland. Here in California, it seems to be in every county.
- Bifurcation. Now imagine that extreme measures are effective in two countries: the USA and China, meanwhile the virus spreads to 90% of the the population in every other country. What then? We cannot hermetically seal ourselves off from the world, bifurcated between the infected and uninfected. Look at the Johns Hopkins map for today, but ignore the circle sizes because they are all going to have a larger radius than the entire map in about 2 weeks.
All three factors yield the same conclusion: countermeasures are about buying time. The policy question is then all about:
A. What are the actions that will reduce R0? (and buy more time)
B. What is the cost-benefit of each action?
Offhand, some of the possible actions that occur to me include (1) No shaking hands, (2) Washing hands more often, (3) No gathering in large groups, (4) isolating certain communities such as nursing homes, (5) shutting schools, (6) closing parks, (7) closing social-space business such as movie theaters and restaurants, (8) making sure to enforce these new laws with police. The “bomb” of policy actions is (9) ordering everyone to shelter-in-place.
What’s missing in the public discourse right now is the word: balance. The conversation should be: How much mitigation (time) is worth how much economic damage? What’s the right balance? It’s fundamentally flawed to frame the policy actions as a binary choice. Even if a national government chose no mitigation, they don’t get maximum prosperity. The Chinese ruined that outcome. Rather, we need to think about mitigation on a scale of 0–10. I agree that zero mitigation is a dangerous policy, and my main argument is that 10 is probably worse. Economic Armageddon will kill more than 1% of the population, I promise you.
Now let’s talk about growth rates.
From Feb 25 to March 20, the number of total U.S. cases rose from 35 to over 19,383. That means the average daily growth rate has been 29.6%. That is a weekly growth rate of about 500%.
The 500% growth rate may easily be an underestimate (the invisible fire). Regardless, if the goal is to lower R0 and therefore the growth rate, let’s suppose all of the measures taken domestically can knock it down by half or even lower. What that does is buys time. That’s valuable, to be sure, but it’s not a cure.
If the growth rate is not reduced, then the U.S. will have over 1 million cases in two weeks (on Saturday, April 4). If the growth rate is cut in half to just 15% daily, then there will be 1 million U.S. cases of Covid-19 on April 15. What about 10% or a heroic 5%? April 28 and May 31.
When I calculated the numbers, they didn’t scare me, and I hope they don’t scare you. Rather, they made me shift my thinking to something like this: “The wave is coming. Maybe later than sooner. Let’s prepare for the wave rather than put all of our eggs into stopping it.” Mentally, this is helpful.
I find myself thinking a lot more about what we can do to manage having hospitals unavailable for treatment. Millions and millions of people will need to be treated at home. By family. Hospital beds are going to be scarce, and that resource should be secured for important people: doctors especially, but also mothers of young children, scientists, etc. Most of us will have to make do with home care, and we need help in getting prepared. We made need supplies of IV fluids for use in the home. We definitely need to ramp up production of oxygen. We need a massive education campaign about how to treat ill family members at home.
Extreme mitigation in the form of The Shutdown is buying our society some time. And I see positive signs that attention is being paid with that time on some vital issues: PPE for health care providers in particular. That’s time worth having. Governors are now realizing that keeping highways working — with clean restrooms for truckers — might be part of the trio of top priorities (along with electricity and plumbing), and mayors are probably realizing that waste management is equally important to city life. When collecting trash becomes a hazardous profession, those workers deserve raises big time. Maybe “buying time” means paying the market prices that a crisis demands.
And there it is. We’re buying time. Big time.