This sounds like outcome bias to me, i.e., believing in retrospect that a decision was the right one because it happened to turn out well. For example, if you decide to drive home drunk and donât crash your car, you could believe based on outcome bias that that was the right decision.
There may also be some hindsight bias going on, where in retrospect itâs easier to claim that something was absolutely, obviously the right call, when, in fact, at the time, based on the available evidence, the optimally rational response might have been to feel a significant amount of uncertainty.
I donât know if youâre right that someone taking their advice from Gregory Lewis in this interview would have put themselves more at risk. Lewis said it was highly uncertain (as of mid-April 2020) whether medical masks were a good idea for the general population, but to the extent he had an opinion on it at the time, he was more in favour than against. He said it was highly uncertain what the effect of cloth masks would ultimately turn out to be, but highlighted the ambiguity of the research at the time. There was a randomized controlled trial that found cloth masks did worse than the control, but many people in the control group were most likely wearing medical masks. So, itâs unclear.
The point he was making with the cloth masks example, as I took it, was simply that although he didnât know how the research was ultimately going to turn out, people in EA were missing stuff that experts knew about and that was stated in the research literature. So, rather than engaging with what the research literature said and deciding based on that information, people in EA were drawing conclusions from less complete information.
I donât know what Lewisâ actual practical recommendations were at the time, or if he gave any publicly. It would be perfectly consistent to say, for example, that you should wear medical masks as a precaution if you have to be around people and to say that the evidence isnât clear yet (as of April 2020) that medical masks are helpful in the general population. As Lewis noted in the interview, the problem isnât with the masks themselves, itâs that medical professionals know how to use them properly and the general population doesnât. So, how does that cash out into advice?
You could decide: ah, why bother? I donât even know if masks do anything or not. Or you could think: oh, I guess I should really make sure Iâm wearing my mask right. What am I supposed to do...?
Similarly, with cloth masks, when it became better-known how much worse cloth masks were than medical masks, everyone stopped wearing cloth masks and started wearing KN95, N95 masks, or similar. If someoneâs takeaway from that April 2020 interview with Lewis was that the efficacy of cloth masks was unclear and thereâs a possibility they might even turn out to be net harmful, but that medical masks work really well if you use them properly, again, they could decide at least two different things. They could think: oh, why bother wearing any mask if my cloth mask might even do more harm than good? Or they could think: wow, medical masks are so much better than cloth masks, I really should be wearing those instead of cloth masks.
Conversely, people in EA promoting cloth masks might have done more harm than good depending on, well, first of all, if anyone listened to that advice in the first place, but, second, on whether any people who did listen decided to go for cloth masks rather than no mask, or decided to wear cloth masks instead of medical masks.
Personally, my hunch is that if very early on in the pandemic (like March or April 2020), there had been less promotion of cloth masks, and if more people had been told the evidence looked much better for medical masks than for cloth masks (slight positive overall story for medical masks, ambiguous evidence for cloth masks, with a possibility of them even making things worse), then people would have really wanted to switch from cloth masks to medical masks â because this is what happened later on when the evidence came in and it was much clearer that medical masks were far superior.
The big question mark above that is I donât know/âdonât remember at what point the supply chain was able to provide enough medical masks for everybody.
I looked into it and found a New York Times article from April 3, 2020 that discusses a company in Chicago that had a large supply of KN95 masks, although this is still in the context of providing masks to hospitals:
One Chicago-based company, iPromo, says it has been in the KN95 importing business for a month. It had previously developed relationships with Chinese supplies for its main business, churning out custom logo-adorned promotional knickknacks like mugs, water bottles, USB flash drives and small containers of hand sanitizer.
The companyâs website advertises KN95 masks at $2.96 apiece for hospitals, with delivery in five to seven days, although its minimum order is 1,000 masks.
More masks are available because coronavirus transmission in China has been reduced. âThey have so much stock,â said Leo Friedman, the companyâs chief executive, during an interview Thursday. âThey ramped up and now itâs a perfect storm of inventory.â
I found another source that says, âMillions of KN95 masks were imported between April 3 and May 7 and many are still in circulation.â But this is also still in the context of hospitals, not the general public. Thatâs in the United States.
I found a Vice article from July 13, 2020 that implies by that point it was easy for anyone to buy KN95 masks. Similarly, starting on or around June 30, 2020, there were vending machines selling KN95 masks in New York City subway stations. Although apparently KN95 masks were for sale in vending machines in New York as early as May 29.
In any case:
It seems quite plausible that pushing people toward medical masks rather than cloth masks sooner would have been beneficial.
Even if people who donât understand the science and donât know how to properly read the research occasionally stumble into the correct conclusion from time to time through sheer luck, that doesnât imply this is the best strategy over a long timespan, over a large sample size of examples.
This sounds like outcome bias to me, i.e., believing in retrospect that a decision was the right one because it happened to turn out well. For example, if you decide to drive home drunk and donât crash your car, you could believe based on outcome bias that that was the right decision.
There may also be some hindsight bias going on, where in retrospect itâs easier to claim that something was absolutely, obviously the right call, when, in fact, at the time, based on the available evidence, the optimally rational response might have been to feel a significant amount of uncertainty.
I donât know if youâre right that someone taking their advice from Gregory Lewis in this interview would have put themselves more at risk. Lewis said it was highly uncertain (as of mid-April 2020) whether medical masks were a good idea for the general population, but to the extent he had an opinion on it at the time, he was more in favour than against. He said it was highly uncertain what the effect of cloth masks would ultimately turn out to be, but highlighted the ambiguity of the research at the time. There was a randomized controlled trial that found cloth masks did worse than the control, but many people in the control group were most likely wearing medical masks. So, itâs unclear.
The point he was making with the cloth masks example, as I took it, was simply that although he didnât know how the research was ultimately going to turn out, people in EA were missing stuff that experts knew about and that was stated in the research literature. So, rather than engaging with what the research literature said and deciding based on that information, people in EA were drawing conclusions from less complete information.
I donât know what Lewisâ actual practical recommendations were at the time, or if he gave any publicly. It would be perfectly consistent to say, for example, that you should wear medical masks as a precaution if you have to be around people and to say that the evidence isnât clear yet (as of April 2020) that medical masks are helpful in the general population. As Lewis noted in the interview, the problem isnât with the masks themselves, itâs that medical professionals know how to use them properly and the general population doesnât. So, how does that cash out into advice?
You could decide: ah, why bother? I donât even know if masks do anything or not. Or you could think: oh, I guess I should really make sure Iâm wearing my mask right. What am I supposed to do...?
Similarly, with cloth masks, when it became better-known how much worse cloth masks were than medical masks, everyone stopped wearing cloth masks and started wearing KN95, N95 masks, or similar. If someoneâs takeaway from that April 2020 interview with Lewis was that the efficacy of cloth masks was unclear and thereâs a possibility they might even turn out to be net harmful, but that medical masks work really well if you use them properly, again, they could decide at least two different things. They could think: oh, why bother wearing any mask if my cloth mask might even do more harm than good? Or they could think: wow, medical masks are so much better than cloth masks, I really should be wearing those instead of cloth masks.
Conversely, people in EA promoting cloth masks might have done more harm than good depending on, well, first of all, if anyone listened to that advice in the first place, but, second, on whether any people who did listen decided to go for cloth masks rather than no mask, or decided to wear cloth masks instead of medical masks.
Personally, my hunch is that if very early on in the pandemic (like March or April 2020), there had been less promotion of cloth masks, and if more people had been told the evidence looked much better for medical masks than for cloth masks (slight positive overall story for medical masks, ambiguous evidence for cloth masks, with a possibility of them even making things worse), then people would have really wanted to switch from cloth masks to medical masks â because this is what happened later on when the evidence came in and it was much clearer that medical masks were far superior.
The big question mark above that is I donât know/âdonât remember at what point the supply chain was able to provide enough medical masks for everybody.
I looked into it and found a New York Times article from April 3, 2020 that discusses a company in Chicago that had a large supply of KN95 masks, although this is still in the context of providing masks to hospitals:
I found another source that says, âMillions of KN95 masks were imported between April 3 and May 7 and many are still in circulation.â But this is also still in the context of hospitals, not the general public. Thatâs in the United States.
I found a Vice article from July 13, 2020 that implies by that point it was easy for anyone to buy KN95 masks. Similarly, starting on or around June 30, 2020, there were vending machines selling KN95 masks in New York City subway stations. Although apparently KN95 masks were for sale in vending machines in New York as early as May 29.
In any case:
It seems quite plausible that pushing people toward medical masks rather than cloth masks sooner would have been beneficial.
Even if people who donât understand the science and donât know how to properly read the research occasionally stumble into the correct conclusion from time to time through sheer luck, that doesnât imply this is the best strategy over a long timespan, over a large sample size of examples.