Comment by ryankemper | Hacker News Reader

Comment by ryankemper | Hacker News Reader

Parent Full thread

I'm sure you're getting weary at this point, but I really need your help understanding what you're saying here, because to me it seems supremely untrue.

First, `1/1-R_0`. This is exactly what Wikipedia says: https://en.wikipedia.org/wiki/Herd_immunity#Mechanics

And it makes intuitive sense that once you infect <= 1.00 people, growth is no longer exponential. So I don't think that point is wrong at all.

> The idea that vaccination and epidemics need the same percent of immunity is completely 100% wrong. An active epidemic is going to infect way more people before dying out than the simple, naive herd immunity calculation will give you. In fact, while an r0 of 2 indicates that you get herd immunity with just 50% of the population, a typical active epidemic with the same r0 would infect 80+% before dying out.

This doesn't make any sense to me. Vaccination is just an artificial way to build immunity. So I don't understand your active epidemic point at all. Or put another way, as the proportion of % recovered goes up, we start approaching the eventual limit where `1/1-R_0`->1. That is to say, in your example we start with R_0 = 2, then as people recover that value slowly starts decreasing until it hits 1 at the herd immunity threshold. It's not clear to me what the discrepancy you're detecting is here.

This is called 'overshoot'.

See here for a good explanation https://twitter.com/CT_Bergstrom/status/1252077930286444545

Thanks. That was helpful.

So then, it does seem that if we successfully contained the virus, and then avoided infection spread until a hypothetical future vaccine is developed, that we could avoid the number of infections required by some amount.

Just to tie it back to the broader lockdown vs not lockdown debate, we could probably say that a successful full containment strategy+vaccination could decrease the net area under the curve. As far as policy is concerned I still think the costs of locking down for that long (particularly given that the time is unbounded) is not worth it, but that is a very valid point that I will need to circle back and weave into the document.

So you are telling me, that you write an article with misstakes and think you should be the person making statements because you are able to write an article?

And you also think, that politicians are doing an economycal suicide just because they like it?

Srsly, wouldn't you assume and shouldn't you assume, that there are experts calculating and estimating that shit on every single day and trying there best to find a reasonable way out of this?

> So you are telling me, that you write an article with misstakes and think you should be the person making statements because you are able to write an article?

Yes, I am a person that makes and is currently making mistakes.

> And you also think, that politicians are doing an economycal suicide just because they like it?

I analyzed the "game theory" of this a bit here: https://www.ryankemper.io/post/2020-04-29-the_case_for_endin...

> Hanlon’s Razor is very relevant here; we think it is not reasonable to assume that they were trying to usher in a techno-totalitarian state. Rather, they were trying to prevent mortality, but their incentive structure is such that it is much worse to have done nothing and later find out that the virus was worse than we thought, than what actually happened, which is to have undertaken actions that were self-destructive and then discovered that the virus was way less deadly than we thought.

You know, i'm an expert in developing software. But i'm an expert in this because i spend years mo-fr 40h min. with time on weekends and after work.

There are plenty of people coming to me and say stuff like 'uh why does that take so long' 'i can do that quickly in an hour' etc. and at the end of the day they are wrong.

In those cases, i would just love for people to accept my expertise and let me do what i'm good at because it costs time dealing with this stuff.

And you know, all those speculations of people who are sitting down for a few hours, writing something, gathering a little bit of data left, a little bit of data right THIS IS RIDICULOUS.

You are not an economist, you are not a doctor, you are not a virologist, you are not the statistics guy. Apparently you are a SRE.

What do you think, your statement actually does? I tell you what it does, if it even does anything: It works against all the experts trying to actually do their fucking job on estimating and deciding on a daily bases about human lives.

Do you know what i decided when corona started? I will, this time, just try to be as undisruptive to the society as i can. I don't have to argue against or for it, i will trust the experts and politicians on this one.

Not everyone needs to form an opinion and also state it.

And yes it might be harder for you to believe in your president right now, i do get that. But let me give you a tip: Whenever everyone would love to stop quarantaen today, i will try to avoid public spaces as long as i can, because the risk of having corona, is actually for me, a bigger problem then just staying low for a few month.

Overshoot is also a function of rates of infection. If each infection results in 0.5 new infections and 16 people are infected, that falls off to ~8, 4, 2, 1 so about doubling. On the other hand if 16,000 people are infected per day it’s still falling off at the same rate, but you get 1000x more infections before it ends.

Well, here's the problem: The statements your making are quantifiably incorrect throughout the article, and by large amounts. The article sounds authoritative, but it's not. It's the definition of Internet misinformation.

I think getting your opinion out there is important, but to be honest, the article needs a heck of a lot more in terms of disclaimers, and much less in terms of confident statements and grandstanding.

I've worked through the best available data. My conclusions:

1) The economic costs of ending the lock-down may be astronomical. This is especially true with what we learn about COVID19 and lung damage (or potentially other organ damage). If even a small fraction of the population is on long-term disability, the costs go up super-quickly.

2) The fundamental costs of the lockdown are cheap. With reasonable economic mitigations, the costs should be that everyone upgrades their car, computer, or similar maybe 6-18 months later, plus an extra 1-5 percent of the GDP.

3) Most of the economic damage of the lockdown, like a cytosine storm, is self-inflicted: bankruptcies, defaults, layoffs, etc. There are reasonable way to manage most of those (and the rest require a very modest stimulus). We haven't taken those steps because we're stupid.

4) If we don't put in systems to manage the economic costs, we'll be super-vulnerable to the next pandemic.

5) This is something which will come up again, and it's also something which is a national security issue. Engineering something like the next COVID19 as a bioweapon is, at this point, within the scope of even poor countries (North Korea, most countries in Africa, etc.), and there's a Moore's Law where the resources go down super-quickly (larger organized crime organizations could probably do this as well now). The point isn't that poor countries are more likely to do this (they're not), but that with 200 countries in the world, the odds that SOMEONE is likely to do this are increasingly high.

> 1) The economic costs of ending the lock-down may be astronomical. This is especially true with what we learn about COVID19 and lung damage (or potentially other organ damage). If even a small fraction of the population is on long-term disability, the costs go up super-quickly.

I have a feeling a lot of people advocating ending the lockdown are doing so on the basis that only old and infirm people die, as if the other option is either an asymptomatic infection or a quick recovery from something flu-like.

But I’ve witnessed some very serious infections, so this colors my perception and pushes me toward continuing lockdowns. To your point, the disease can be debilitating foR relatively young, healthy people. Have you ever gotten the flu and then had to re-learn how to swallow after spending a month in the hospital?

Yes corona is mostly deadly to older people, but even for those who do not die there are negative health outcomes which impact their ability to work and take care of themselves. What is the economic impact of that? Why is it not factored into the cost/benefit analysis of opening up?

> Yes corona is mostly deadly to older people, but even for those who do not die there are negative health outcomes which impact their ability to work and take care of themselves. What is the economic impact of that?

We need to know the incidence of these issues. Response needs to be completely different in case they're the majority of cases, or if they happen in the minority.

So far the evidence collected from what I've seen is case reports, so nothing clear or definitive.

> First, `1/1-R_0`. This is exactly what Wikipedia says: https://en.wikipedia.org/wiki/Herd_immunity#Mechanics

I have no expertise in this area, but Wikipedia does not say:

    1/(1 - R_0)

It's:

    1 - (1/R_0)

Which makes much more sense to me on a math footing. You should probably fix that in your article so it doesn't confuse other pedants like myself.

Doh! Thanks for catching that. That is a really glaring mistake on my part.

(The irony in me having said it was "exactly" what Wikipedia says is not lost on me :P)

https://gitlab.com/ryankemper/writings/-/commit/093ade629447...

No worries - it was clearly just a typo :-)

It is fun to imagine the negative herd immunity threshold implied by the erroneous form of the equation though :P

Say R0 is 2, 1/(1 - R0) means that we already hit herd immunity before SARS-CoV-2 even existed!

The frightening one for me was R0 == 1: Basically, we'd need a positive or negative infinite percentage of people to be infected depending on which direction you approach it from.

Even when the R0 reaches 1.0 those who are infected will still infect one more person (on average). Infections continue to happen after the R0 is below 1.0.

Thanks, that does make intuitive sense. I wonder for a virus like SARS-CoV-2 that has a high R_0 and thus requires maybe 80% of the population to be immune for full herd immunity, if that means that the overshoot would be pretty mild?

It would mean the overshoot would likely go close to 100%, but it is complex to model as not everyone is equally likely to be infected - basically the population is not uniform. Epidemiologist do model this, but it requires relatively complex models.

Reply on news.ycombinator.com