It turns out I’ve been wildly optimistic!

  

I apologize, but I just discovered this morning that I’d made a simple error in calculating the 3-day percent increase in total cases. Because of that error, my projections of total cases and total pandemic deaths, which are based on that 3-day percent change, were far lower than they should have been.

I have used the corrected numbers in this post, but to help you understand the magnitude of my underestimates (which is huge), I’m including, after each number that depends on the erroneous projection of total cases, what I would have stated before I noticed the error.

This doesn’t apply to my projections of total daily deaths, which are based on the 3-day percent change in reported daily deaths, not the 3-day change in reported total cases.

All numbers are based on yesterday’s reported figures of total confirmed cases, total deaths and total recoveries, published on Worldometers as of about 8 PM EDT April 4.

I. Numbers based on total cases, actual and projected

Total US confirmed cases: 311,637

Increase in cases since previous day: 34,030 (vs. 32,165 increase yesterday)

Percent increase in cases since yesterday: 12% (vs. 13% yesterday)

Percent increase in cases since 3 days previous: 45% (vs. 47% yesterday) I was greatly underestimating this number. Since I always use this number for my projection of total cases, my projections of everything except daily deaths were greatly underestimated.

“Set in stone” US deaths* over course of pandemic:  403,356 (based on 4% case mortality rate) This compares to 107,163, which was based on my erroneous calculation.

*This number assumes a) Total cases grow by 30% into the future (= yesterday’s 3-day growth rate in cases); b) We impose a massive lockdown, with prohibition of all non-essential travel, today; c) New cases drop to zero in 28 days, because of the lockdown; d) testing is widely available by the 28-day mark; and e) case mortality rate = 4%. To consider a 6% mortality rate, multiply each projection by 1.5. For 8%, double it. For comparison, Italy’s case mortality rate is currently 11.75%.

Projected as of April 12 (7 days from today):

These numbers answer the question: What would happen if we wait seven days to totally lock down the US, based on the assumptions below (which frankly are themselves wildly optimistic).

Total expected cases*: 846,320 This compares to 568,645 based on the erroneous projections.

Total expected deaths set in stone* over course of pandemic: 1,076,775 This compares to 354,040 based on the erroneous projections.

* The expected cases and deaths set in stone numbers assume a) Total cases grow by 30% into the future (= yesterday’s 3-day growth rate in cases); b) We impose a massive lockdown, with prohibition of all non-essential travel, on April 12; c) New cases drop to zero in 28 days, because of the lockdown; d) Testing is widely available by the 28-day mark; and e) case mortality rate = 4%. To consider a 6% mortality rate, multiply each projection by 1.5. For 8%, double it. For comparison, Italy’s case mortality rate is currently 12.25%.

Projected as of April 19 (14 days from today):

These numbers answer the question: What would happen if we wait 14 days to totally lock down the US, based on the assumptions below (which frankly are themselves wildly optimistic).

Total expected cases*: 1,997,510 This compares to 1,029,598, based on the erroneous projections.

Total deaths set in stone* over course of pandemic: 2,585,407 This compares to 645,833, based on the erroneous projections.

* The expected cases and deaths set in stone numbers assume a) Total cases grow by 30% into the future (= yesterday’s 3-day growth rate in cases); b) We impose a massive lockdown, with prohibition of all non-essential travel, on April 19; c) New cases drop to zero in 28 days, because of the lockdown; d) Testing is widely available by the 28-day mark; and e) case mortality rate = 4%. To consider a 6% mortality rate, multiply each projection by 1.5. For 8%, double it. For comparison, Italy’s case mortality rate is currently 11.75%.

Date on which 200,000 total pandemic deaths will be set in stone: March 31  This compares to April 12 based on erroneous projections. In other words, we passed this milestone five days ago, meaning we passed the top range of the White House’s projection of total pandemic deaths (240,000) the very day that projection was made public.

Date on which 500,000 deaths will be set in stone: April 6 This compares to April 16, based on the erroneous projections.

Date on which 1 million total pandemic deaths will be set in stone: April 12 This compares to May 2, based on the erroneous projections.

II. Numbers based on total deaths, reported and projected

None of these numbers are changed, since they’re not based on the total case projections.

Total US deaths as of yesterday: 8,454

Increase in deaths since previous day: 1,048 (vs. 1,308 yesterday)

Percent increase in deaths since previous day: 14% (vs. 21% yesterday)

Projected* number of actual deaths on 4/12 alone: 5,876

Projected* number of actual deaths on 4/17 alone: 12,817

* Projected deaths = previous day’s new deaths number, grown by that day’s 3-day percentage growth rate. Note this is calculated completely differently from the deaths set in stone, which refers to projected deaths over the entire pandemic, and is calculated by multiplying expected cases by the mortality rate

Date on which the number of new deaths on that day will exceed the toll of Sept. 11: April 11

III. Reported case mortality rate so far in the pandemic in the US:

These numbers are also unaffected by the error I made.

Total Recoveries in US as of yesterday (4/2): 14,828

Total Deaths as of yesterday: 8,454

Deaths so far as percentage of closed cases (=deaths + recoveries): 36% Let’s be clear. This means that, of all the coronavirus cases that have been closed so far in the US, 36% of them have resulted in death (compare that to the 4% mortality rate I’ve been using to calculate total pandemic deaths, based on total cases). Of course, this number will come down as time goes on and more cases are closed in which the victim recovered. But it’s only come down by about 4 percentage points since Worldometers started publishing the recovery rate on March 26, and on about half the days, it’s gone up. I’d say it’s much more likely my 4% mortality rate will turn out to be too low, after the pandemic’s over and all of the bodies have been counted, than it will be too high.

Note that, as opposed to total reported cases and total deaths, there is no downward trend in this number.

I hope you’ll look over these numbers and consider what they mean. For me, the bottom line is the “set in stone” numbers for total pandemic deaths. They mean that, even if we instituted a total lockdown today (and the other assumptions that you can read for yourself), we will have over 400,000 total deaths during the pandemic. If we wait 7 days to do that, we’ll have over 1 million. If we wait 14 days, we’ll have over 2.5 million. What are we waiting for?