The pessimists were correct about Covid

In a recent post, David Henderson contrasts the views of Neil Ferguson and Jay Bhattacharya:

The first was Tyler’s praise early in the pandemic of “expert” modeler Neil Ferguson, and his related action, with his Emergent Ventures project, of sending a large check to Ferguson and Ferguson’s Imperial College team. If you check the link just above, you’ll see that Tyler thought, correctly, that Ferguson had a huge impact on the U.K. and U.S. governments’ responses to Covid. Because Tyler is so well respected, not just in the United States but also internationally, that large payment put the imprimatur on some very bad modeling. It was that modeling that led Boris Johnson and Donald Trump to recommend lockdowns, and Johnson and many U.S. governors to impose lockdowns. Would they have done that without Tyler’s support of Ferguson? Probably. But if Cowen had recognized how little we knew at first and taken more seriously the early seroprevalence studies, such as that done by Jay Bhattacharya, that showed that the infection fatality rate from Covid was a small fraction of the case fatality rate, and if Tyler had publicized that, there might have been more pushback early against the lockdowns.

I have a different impression of the debate, one in which the pessimists were correct and the optimists were wildly off base.  David links to a post by Tyler Cowen, which itself links to this NYT story from March 16, 2020:

Sweeping new federal recommendations announced on Monday for Americans to sharply limit their activities appeared to draw on a dire scientific report warning that, without action by the government and individuals to slow the spread of coronavirus and suppress new cases, 2.2 million people in the United States could die. . . .

Dr. Birx’s description of the findings was consistent with those in the report, released on Monday by an epidemic modeling group at Imperial College London. The lead author of the study, Neil Ferguson, an epidemiology professor, said in an interview that his group had shared their projections with the White House task force about a week ago and that an early copy of the report was sent over the weekend.

Two years later, it looks like Ferguson’s estimates were basically correct.  The official US Covid death toll is over 900,000 (although if unreported Covid deaths were included it would be well over a million dead.)  But that’s not what Ferguson was estimating.  Rather, his claim was that 2.2 million would die without precautions and without a vaccine.  That seems quite plausible.  No one died of Covid in the large retirement complex where my 95-year old mom lives in Arizona, whereas without social distancing and without a vaccine they would have experienced many Covid deaths as the virus quickly spread though our population.  Of course, that’s not to say all Covid avoidance strategies were wise; in my view many were unwise on a cost/benefit basis, and some were absurd.  But the pessimists were correct on the specific point that the death toll would be horrific if people didn’t try to avoid Covid until a vaccine came along.  

Of course even the optimists favored protecting the very old, but how accurate were their estimates of the death rate for the rest of us?  Consider the views of Jay Bhattacharya, expressed in a Nov. 20, 2020 interview with Russ Roberts:

First you find that there’s a very steep age gradient in the survival rate. People who are under 70–if now, there’s now there’s like 50-some of these studies–so you can criticize mine but now you got to go after 49 other people–if you’re under 70, the infection survival rate is something like 99.95%. 99.95%, for under 70.

Bhattacharya had an extra 8 months to make a better estimate than Ferguson and instead made a ridiculous claim, unless I am misreading what he is saying.  He seems to be claiming that only 0.05% of people under 70 who get infected with Covid end up dying from the disease.  The actual figure is not known with precision. But given that roughly 0.10% of Americans under 70 (about 300,000) have already died of Covid, with thousands more dying every week, and given that this occurred despite widespread social distancing and despite widespread use of vaccines after 2020, I think we can assume that the actual infection fatality rate in an unvaccinated population would be at least 3 or 4 times higher than Bhattacharya suggested.  And again, he benefited from an extra 8 months of data beyond what Ferguson had to work with.

PS.  If someone wants to say that Ferguson should have said, “without action by the government and/or individuals” instead of “without action by the government and individuals”, I would not disagree.  But again, David’s discussion is of infection fatality rates, and it seems Ferguson was pretty accurate on that point.  Bhattacharya was not.