The Great Barrington declaration is receiving lots of discussion. https://gbdeclaration.org/  GB makes the case for a herd immunity strategy while protecting the elderly. Like @paulmromer I agree that it should be discussed as it is a view held by many. But, it is flawed [1/n]

First, note that several prominent economists proposed it including, notably, these 4 including Daron Acemoglu and @IvanWerning in this paper. https://economics.mit.edu/files/19698  They took the standard epidemiological approach (SIR model) and augmented it. [2/n]

Second, if your belief is that reaching herd immunity anyway is inevitable (that is, you can't eliminate the virus, even with a vaccine, in reasonable time), the only way out is a `natural' (non-interventionist) outcome. See this by @LukaszRachel https://drive.google.com/file/d/1x8E2dxQsEKhM2d1aGXP5RrkHHb9yndQM/view. [3/n]

Third, it is not immediately obvious that continual waves of lockdowns as a means of flattening the curve is optimal. But we are seeing that happening world-wide. [4/n]

However, the reason why GB is wrong is that it makes an economic case (social distancing hurts the economy and people in it) without actually using economics the whole way -- to embed it in the epidemiological model. [5/n]

As I have argued here, that is a big error ( https://www.nber.org/papers/w27632 ). Govt lockdowns etc don't drive most behaviour -- people do. We have social distancing and WFH because people want that to minimise their risks of getting Covid-19. Even for many young people the ... [6/n]

... prospect of being a long-hauler or infecting someone more vulnerable is enough to cause behaviour change. (The students only partied when they moved from home). [7/n]

Once you understand that people are responsible for social distancing, you see immediately that GB makes no sense. They are advocating for an option that DOES NOT EXIST because people aren't going to return to normal while the virus is around and especially not if it rages. [8/n]

This means that you should see intermittent lockdowns as a means of keeping the virus enough in check that, in between, people do act more normally and the entire economy does not collapse. I don't like them, however. [9/n]

Because the real path out of this is to actually rid ourselves of this thing. Herd immunity is too slow (it will take decades if that.) We rid ourselves of SARS and MERS. This is many-fold harder but still worth it. We test, trace and isolate and we do it bigly. [10/n]

What's more, we must have resolve and be relentless on that. No 'what voters want' crap. It isn't clear what they want anyway. If that same fraction of US voters had their way, the US would not have entered WW2. That argument is a shit argument. [11/n]

In summary, Great Barrington is WRONG because it advocates for an option that does not exist. We cannot quickly get to herd immunity because people choose to protect themselves. We need to clearly convince people it isn't an option. [12/12]