Strong work: thank you!
I believe there's a small mistake: in the first table (after "In equilibrium, we see the following amounts of sars-cov-2 relative to no filtration:"), I believe the second column should be labeled "presence", not "reduction".
Lots of cool data here—thank you!
(Edited to remove a comment based on misremembering the Most Penetrating Particle Size)
I'm overdue for making another pass through the latest data, so my opinions on this are weakly held. But briefly: my current thinking is that many people (including Zvi and me) have made the mistake of conflating a number of different phenomena into the single category of "long covid". I believe Zvi is correct that if a large number of people were suffering long-term debilitating impact, we'd know it.
I suspect that after I plow through the data again, I'll update significantly in the direction of believing that:
Anecdata: I don't know anyone who's been profoundly impacted by covid for a very long time. I know multiple people who've suffered significant impairment for weeks / months.
The impact of long covid is (small incidence #) x (large impact #), and the impact of post-acute covid is (medium incidence #) x (medium impact #). I think for most people, the total expected impact of getting covid will be somewhere between a day and a few weeks of useful live lost, with large error bars and much of the impact being in low-likelihood events.
Eliezer, back in 2009:
Yet there is, I think, more absent than present in this "art of rationality"—defeating akrasia and coordinating groups are two of the deficits I feel most keenly.
This is not a small project, and I'm too new here to have a clear sense of how it might happen. But this feels important.
To more directly address your initial question: to my mind, Zvi's analysis isn't obviously wrong, but it's pretty far to the optimistic end of what I see as the reasonable range.
My best model suggests that for me (55 but very healthy), 1,000 µCoV of risk has an expected life cost of about 15 minutes.
Based on that, my approach to risk is very situational. Is eating in a restaurant worth 75 minutes of lying in bed with flu wishing I was dead (based on today's numbers)? No, it isn't. Is going to a friend's wedding worth that? Yes, it probably is.
I'd love to see a more structured approach to the kinds of questions you're raising here. LW does a good job of creating a space for smart people to share their thoughts about individual topics, but isn't so good at building toward a coherent synthesis of all those pieces.
The original microCOVID white paper did a good job of summarizing a lot of relevant evidence back in the day, but (like the rest of the site) has been only sporadically updated.
Put me down as tentatively interested in being part of some larger project, if one comes together.
Also: may I humbly request that if this ever takes off, it be named LessSick?
That all makes complete sense.
And yes, the specifics of the population make a huge difference. Honestly, I think that accounts for the breadth of my estimate range more than uncertainty about abstract test performance does.
I think it's important to emphasize that antigen+ people are much more contagious than antigen-. It's hard to quantify that, but based on typical differences in Ct value, it's probably a very substantial difference (factor of 10+?).
You're absolutely right that the reference class is the key issue (if there's one thing I've learned from hanging out with epidemiologists, it's that they're always grumpy about people using the wrong denominator).
In a perfect world, where everyone with any symptoms whatsoever stayed home and was scrupulous about following what the CDC exit guidance ought to be, antigen tests would be significantly less useful. But in the real world, people absolutely go out when they have mild symptoms. That's advocated for in the comments right below this, which are from people who are presumably much more conscientious than average.
IMHO, the biggest value of antigen tests is in catching people who are mildly symptomatic but think it's just allergies / they had a negative test last week so it can't be covid / they're probably over the worst of it. Within my (not enormous) extended social circle, I'm aware of two very recent cases when antigen tests flagged as infectious people who would otherwise have been out and about despite having mild symptoms.
Let me give you two answers for the price of one:
FDA and others have been very clear about this: you should use the tests as directed.
I (a decades-long amateur epidemiologist who's done a deep dive on antigen test research), my partner (a medical epidemiologist who works full-time on Covid), and several other epidemiologists I'm aware of, all use throat + nasal swabs.
I wouldn't worry at all about false positives: they really haven't been an issue with antigen tests. If I got a positive from a throat + nasal swab, I'd follow it up with a nasal-only swab or a PCR, just to be sure.
There is non-zero risk that you'd get false negatives, by some unknown mechanism. That seems unlikely given that some countries like the UK use throat swabs, but it's possible. It's my well-informed but not data-supported belief that the benefit of swabbing your throat probably exceeds the downside.
This stuff is super hard.
I'd recommend (with reservations) Consent Academy, who do a lot of training on incident response, accountability processes, etc. They're good folks who have figured out a lot of really useful things about doing this kind of work.
Their classes can sometimes get pretty rambling and theoretical, but I've learned a lot from them.