BTRTN: Why the Coronavirus Numbers Scare Me

Tom on the coronavirus.

I am neither a scientist nor a medical professional.  Nor am I even a professional statistician.  But I do have some facility with numbers – and the coronavirus numbers scare me.

My goal here is not to cause panic.  But I do believe that in order to make the best possible personal decisions, both for ourselves and for the common good, we all need to understand the math.

Let me share some data with you.

We now have over 2,000 cases of the coronavirus in the United States – 2,144 as of yesterday.  On March 1, just about two weeks ago, we had 42 cases.  That is a growth rate of 42% per day.  If that rate persists, we’ll hit the 100,000 cumulative case mark on March 24 – in 10 days -- and the 1,000,000 mark one week later.

In reality the daily growth rate has slowed down a bit in the past few days.  Over the last three days it has been 29%, 33% and 34%.  Let’s say it continues at 30%.  That pushes those dates back a bit:  100,000 cumulative cases by March 28, 1,000,000 by April 5.

Let’s say the daily trend continues to decline, with the impact of the cancelled events, social distancing and common sense taking hold.   Let’s drop it to 20%.  That takes it to 100,000 cases by April 4, and 1,000,000 by April 29.  How about all the way down to 10%?  May 17 and June 10.  And 5%?    May 31 and July 17.

Let’s look at the trend in Italy.  Italy, as you know from the headlines, is having a terrible time with the coronavirus.   But looking at this chart, you can see that our trend is right with Italy -- just about eleven days behind them.  Their growth rate is in the 20%+ range, and they are up to more than 15,000 cases. 

Rates of change persist until something happens to slow them down.  And the Italian government basically shut down the entire country three days ago.  All shops in the entire country have been shut down, with the exception of supermarkets, pharmacies and a few others.  They had already banned travel within the country (except for work or health reasons), and shut down all the schools.  (Spain and France just announced, minutes ago, that they are taking similar steps.)

We have not taken any actions remotely resembling that – in fact we have taken little federal action at all within our borders; almost all of our shutdowns have been done voluntarily on a local basis by governors, mayors, or businesses (such as the NBA).

Days	Italy		USA
	Cumulative Covid-19 Cases	% Change Per Day	Cumulative Covid-19 Cases	% Change Per Day
Day Zero >>	Feb 22		Mar 3
1	9		85
2	76	744%	111	31%
3	124	63%	175	58%
4	229	85%	252	44%
5	322	41%	352	40%
6	400	24%	495	41%
7	650	63%	643	30%
8	888	37%	932	45%
9	1128	27%	1203	29%
10	1689	50%	1598	33%
11	2036	21%	2144	34%
12	2502	23%
13	3089	23%
14	3858	25%
15	4636	20%
16	5883	27%
17	7375	25%
18	9172	24%
19	10149	11%
20	12462	23%
21	15113	21%

What is my point?  Apart from the fact that we should be prepared for more drastic government action on the horizon, we have to take proper precautions ourselves.  We have to limit our contacts, each and every one of us, to only those that are necessary.  We are seeing entities take action, state by state, city by city, event by event.  Now it has to be person by person.   

We have to understand that the best way to combat COVID-19 is to cut out any but the most essential of human contact.  I cannot pass judgment on those who need to show up to work to earn a living, apart from asking you to lobby to work from home if your job is capable of being done remotely, and to take precautions at work with hygiene and social distancing.

But there is really no good reason to be going to restaurants, the movies, the mall, the museum, the gym, and the like, or traveling anywhere for pleasure (or in the mistaken belief that it is safer elsewhere – you may just be bringing the darn thing there). 

The only way to battle this is to, yes, “flatten the curve.”  We have to attack the rate of change.  The more we can slow down the rate of new cases, the greater the chance that we will not overwhelm our health system at some point.  Any personal decision that reduces the risk of spread is a good one.

The decision by the NBA to cancel their season was a jolt for our society, but we appear to need another jolt or two, one that governs our own actions.  We cannot wait for the federal government to tell us what to do.  We must take personal responsibility – and stay home as much as we can.

Let me quote from yesterday’s The New York Times – the basic point is that we CAN affect those rates of change to avoid horrible scenarios.  But we have to act.

“The assumptions fueling those scenarios are mitigated by the fact that cities, states, businesses and individuals are beginning to take steps to slow transmission, even if some are acting less aggressively than others. The C.D.C.-led effort is developing more sophisticated models showing how interventions might decrease the worst-case numbers, though their projections have not been made public.

'When people change their behavior,' said Lauren Gardner {Ed.: No relation}, an associate professor at the John Hopkins Whiting School of Engineering who models epidemics, “those model parameters are no longer applicable,” so short-term forecasts are likely to be more accurate. 'There is a lot of room for improvement if we act appropriately.'

Those actions include testing for the virus, tracing contacts, and reducing human interactions by stopping mass gatherings, working from home and curbing travel. In just the last two days, multiple schools and colleges closed, sports events were halted or delayed, Broadway theaters went dark, companies barred employees from going to the office and more people said they were following hygiene recommendations.”

The key here to is be very aggressive in how we define “appropriate action.”  Don't be content with halfway measures.

So please – for all of us – stay home as much as you can.