1. What's wrong with the "Great Barrington Declaration"? It's lopsided, it's downplaying risks, it rests on wrong assumptions, and it has already failed the test of reality. It's a not-so-great declaration, if you will. Thread, with quotes from the declaration's text:

2. The GBD laments the bad consequences of vaguely defined lockdowns - but compared to what? That's one-sided complaining of costs without contrasting them with the severe cases and deaths avoided by controlling the epidemic until vaccines arrive.

3. Side note: 'But Ioannidis (and a GBD coauthor) have shown lockdowns don't work...' No, they haven't:
https://onlinelibrary.wiley.com/doi/abs/10.1111/eci.13518 https://twitter.com/AndreasShrugged/status/1349464781145731073

4. This emphasis of the lockdown consequences for the working class and underprivileged disregards that Covid-19 has overproportionally affected precisely these groups in the U.S. and elsewhere (jobs with high infection risk, poor health care,...).

5. Aged like milk in the sun. GBD came out in October, the first very good vaccine results came out in November 2020. GBD needs the lack of a better alternative for its infection propagation to make sense - that's why the vaccines have pulled the rug from under the GBD's feet.

6. Here the GBD disregards that the concern regarding children and Covid has never been the health risks for children alone but has also been (and still is) their potential role as weakly-symptomatic spreaders of the virus.

7. That's obviously wrong. Until herd immunity (HI) is reached, an awful lot of people will be infected, making the risk of infection explode. Even when HI is reached, the epidemic still has to peter out, which involves many additional infected. Chart: @CT_Bergstrom

8. That's also not correct. There are many pathogens against which we have never reached HI. How a HI against Corona will look like, whether it can be reached, and whether it is actually necessary is still debated among (serious) scientists. For example: https://humsci.stanford.edu/events/2021-04-07/science-herd-immunity

9. Let's assume HI is reached at 60% of the population being immune. 78% of U.S. population are below age 60. Taking severe obesity into account leaves ~70%. Let the virus rip through 80% of them: 0.7 x 0.8=0.56=56% infected. Already this 'optimistic' example fails to reach HI.

10. But actually, GBD doesn't make it very clear who deserves/needs protection and who doesn't. That's the Trojan Horse of GBD: Make sensible suggestions for a very small group (nursing home residents) to distract from the high risk for many unprotected people at advanced age.

11. Ironically, EU has first vaccinated nursing homes and very old people due to low supply, thereby created the setting where GBD says it's fine to go back to normal. But doing only a fraction of what GBD suggests has made ICU and deaths soar again in many countries. It's junk.

12. Turns out @tylercowen and I had the same Sunday musings: "Why take this weird, hinky attitude toward the science for no good reason?" https://marginalrevolution.com/marginalrevolution/2021/04/gbd.html