Just Another Thing or Two about COVID-19

Though it’s tough to make predictions, especially about the future, and I sort of promised not to make any more predictions about the spread of COVID-19 in the United States because the data are unreliable (examples at the link and here). But I can’t resist saying a few more things about the matter.

Specifically, since my last substantive post about COVID-19 statistics, I now project 2 million cases and 135,000 deaths by mid-August, as against my earlier projections of 1.3 million and 90,000. The new estimates rely on the same database as the old ones, so they aren’t any more reliable than the old ones.

But I have revised my calculations so that they are based on 7-day average numbers of cases and deaths. This is an attempt to smooth over obvious lags in reporting (sudden drops in numbers of cases and deaths followed by sudden surges).

The equations in these two graphs …

… yield these projections:

Those are nationwide numbers. The good news (pending the results of “re-opening”) is that the daily number of new cases has declined sharply from the peaks of late March and late April. But there’s still a long way to go. The first graph in this post is worrisome because recent observations are a bit above the trend line; that is, the incidence of new cases may not be declining quite as rapidly as the equation suggests.

The number of new deaths has declined also, from the peak 7-day average of 2,041 on April 21 to 1,430 as of May 15. Overall, the rate of new deaths per new case seems to have stabilized at 5.7 percent. (The overall percentage will be somewhat higher because the deaths/case rate was higher than 5.7 for quite a while.)

Of course, the situation varies widely from State to State (and, obviously, within each State):

Regional and state variations in death rates
(I am using same assignment of States to regions as used by my data source.)

Nine of the 12 States of the Northeast (including D.C.) are among the top 12 in deaths per resident. The exceptions are the more rural Northeastern States: Main, New Hampshire, and Vermont.

In general, States with large, densely populated metropolitan areas have fared worse than less-urbanized States with smaller cities. That’s unsurprising, of course. But it also underscores the resistance of large swaths of the populace to “New York” rules.


Other related posts:

Contagion Nation?
“Give Me Liberty or Give Me Death”