Posts

History's Biggest Natural Experiment 2020-03-24T02:56:30.070Z · score: 97 (44 votes)
COVID-19's Household Secondary Attack Rate Is Unknown 2020-03-16T23:19:47.117Z · score: 63 (16 votes)
A Significant Portion of COVID-19 Transmission Is Presymptomatic 2020-03-14T05:52:33.734Z · score: 115 (41 votes)
Credibility of the CDC on SARS-CoV-2 2020-03-07T02:00:00.452Z · score: 196 (81 votes)
Effectiveness of Fever-Screening Will Decline 2020-03-06T23:00:16.836Z · score: 68 (26 votes)
For viruses, is presenting with fatigue correlated with causing chronic fatigue? 2020-03-04T21:09:48.149Z · score: 16 (5 votes)
Will nCoV survivors suffer lasting disability at a high rate? 2020-02-11T20:23:50.664Z · score: 125 (39 votes)
Jimrandomh's Shortform 2019-07-04T17:06:32.665Z · score: 29 (4 votes)
Recommendation Features on LessWrong 2019-06-15T00:23:18.102Z · score: 62 (19 votes)
Welcome to LessWrong! 2019-06-14T19:42:26.128Z · score: 122 (72 votes)
User GPT2 is Banned 2019-04-02T06:00:21.075Z · score: 64 (18 votes)
User GPT2 Has a Warning for Violating Frontpage Commenting Guidelines 2019-04-01T20:23:11.705Z · score: 50 (18 votes)
LW Update 2019-03-12 -- Bugfixes, small features 2019-03-12T21:56:40.109Z · score: 17 (2 votes)
Karma-Change Notifications 2019-03-02T02:52:58.291Z · score: 96 (26 votes)
Two Small Experiments on GPT-2 2019-02-21T02:59:16.199Z · score: 56 (22 votes)
How does OpenAI's language model affect our AI timeline estimates? 2019-02-15T03:11:51.779Z · score: 51 (16 votes)
Introducing the AI Alignment Forum (FAQ) 2018-10-29T21:07:54.494Z · score: 91 (34 votes)
Boston-area Less Wrong meetup 2018-05-16T22:00:48.446Z · score: 4 (1 votes)
Welcome to Cambridge/Boston Less Wrong 2018-03-14T01:53:37.699Z · score: 4 (2 votes)
Meetup : Cambridge, MA Sunday meetup: Lightning Talks 2017-05-20T21:10:26.587Z · score: 0 (1 votes)
Meetup : Cambridge/Boston Less Wrong: Planning 2017 2016-12-29T22:43:55.164Z · score: 0 (1 votes)
Meetup : Boston Secular Solstice 2016-11-30T04:54:55.035Z · score: 1 (2 votes)
Meetup : Cambridge Less Wrong: Tutoring Wheels 2016-01-17T05:23:05.303Z · score: 1 (2 votes)
Meetup : MIT/Boston Secular Solstice 2015-12-03T01:14:02.376Z · score: 1 (2 votes)
Meetup : Cambridge, MA Sunday meetup: The Contrarian Positions Game 2015-11-13T18:08:19.666Z · score: 1 (2 votes)
Rationality Cardinality 2015-10-03T15:54:03.793Z · score: 21 (22 votes)
An Idea For Corrigible, Recursively Improving Math Oracles 2015-07-20T03:35:11.000Z · score: 5 (5 votes)
Research Priorities for Artificial Intelligence: An Open Letter 2015-01-11T19:52:19.313Z · score: 23 (24 votes)
Petrov Day is September 26 2014-09-18T02:55:19.303Z · score: 24 (18 votes)
Three Parables of Microeconomics 2014-05-09T18:18:23.666Z · score: 25 (35 votes)
Meetup : LW/Methods of Rationality meetup 2013-10-15T04:02:11.785Z · score: 0 (1 votes)
Cambridge Meetup: Talk by Eliezer Yudkowsky: Recursion in rational agents 2013-10-15T04:02:05.988Z · score: 7 (8 votes)
Meetup : Cambridge, MA Meetup 2013-09-28T18:38:54.910Z · score: 4 (5 votes)
Charity Effectiveness and Third-World Economics 2013-06-12T15:50:22.330Z · score: 7 (12 votes)
Meetup : Cambridge First-Sunday Meetup 2013-03-01T17:28:01.249Z · score: 3 (4 votes)
Meetup : Cambridge, MA third-Sunday meetup 2013-02-11T23:48:58.812Z · score: 3 (4 votes)
Meetup : Cambridge First-Sunday Meetup 2013-01-31T20:37:32.207Z · score: 1 (2 votes)
Meetup : Cambridge, MA third-Sunday meetup 2013-01-14T11:36:48.262Z · score: 3 (4 votes)
Meetup : Cambridge, MA first-Sunday meetup 2012-11-30T16:34:04.249Z · score: 1 (2 votes)
Meetup : Cambridge, MA third-Sundays meetup 2012-11-16T18:00:25.436Z · score: 3 (4 votes)
Meetup : Cambridge, MA Sunday meetup 2012-11-02T17:08:17.011Z · score: 1 (2 votes)
Less Wrong Polls in Comments 2012-09-19T16:19:36.221Z · score: 79 (82 votes)
Meetup : Cambridge, MA Meetup 2012-07-22T15:05:10.642Z · score: 2 (3 votes)
Meetup : Cambridge, MA first-Sundays meetup 2012-03-30T17:55:25.558Z · score: 0 (3 votes)
Professional Patients: Fraud that ruins studies 2012-01-05T00:20:55.708Z · score: 16 (25 votes)
[LINK] Question Templates 2011-12-23T19:54:22.907Z · score: 1 (1 votes)
I started a blog: Concept Space Cartography 2011-12-16T21:06:28.888Z · score: 6 (9 votes)
Meetup : Cambridge (MA) Saturday meetup 2011-10-20T03:54:28.892Z · score: 2 (3 votes)
Another Mechanism for the Placebo Effect? 2011-10-05T01:55:11.751Z · score: 8 (22 votes)
Meetup : Cambridge, MA Sunday meetup 2011-10-05T01:37:06.937Z · score: 1 (2 votes)

Comments

Comment by jimrandomh on Has the effectiveness of fever screening declined? · 2020-03-27T22:27:15.276Z · score: 4 (2 votes) · LW · GW

For now, mods do it. This will be expanded to all users and to a wider variety of tags when tagging leaves beta.

Comment by jimrandomh on History's Biggest Natural Experiment · 2020-03-25T18:00:35.440Z · score: 5 (3 votes) · LW · GW

It would show up as people with a particular year of birth having a much lower risk than people born one year earlier or later. Since most research includes collecting date of birth, this should be easy to check.

Comment by jimrandomh on Virus As A Power Optimisation Process: The Problem Of Next Wave · 2020-03-22T22:43:43.795Z · score: 13 (6 votes) · LW · GW

Biological global catastrophic risks were neglected for years, while AGI risks were on the top.

This is a true statement about the attention allocation on LessWrong, but definitely not a true statement about the world's overall resource allocation. Total spending on pandemic preparedness is and was orders of magnitude greater than spending on AGI risk. It's just a hard problem, which requires a lot of expensive physical infrastructure to prepare for.

Comment by jimrandomh on Will nCoV survivors suffer lasting disability at a high rate? · 2020-03-22T04:21:51.304Z · score: 3 (2 votes) · LW · GW

"Impaired consciousness" doesn't sound unusual for patients with severe fever, but five strokes out of 214 hospitalized patients is pretty noteworthy.

Comment by jimrandomh on SARS-CoV-2 pool-testing algorithm puzzle · 2020-03-21T06:23:20.857Z · score: 2 (1 votes) · LW · GW

It's a newspaper article based on an unpublished paper; that reference class of writing can't be trusted to report the caveats.

(I could be wrong about the mechanics of PCR; I'm not an expert in it; but the article itself doesn't provide much information about that.)

Comment by jimrandomh on SARS-CoV-2 pool-testing algorithm puzzle · 2020-03-20T18:19:16.943Z · score: 2 (1 votes) · LW · GW

This can only be used on groups where everyone is asymptomatic, and there will be low limits on the pool size even then.

The first step of a PCR test is RNA amplification; you use enzymes which take a small amount of RNA in the sample, and produce a large number of copies. The problem is that there are other RNA viruses besides SARS-CoV-2, such as influenza, and depending when in the disease course the samples were taken, the amount of irrelevant RNA might exceed the amount of SARS-CoV-2 RNA by orders of magnitude, which would lead to a false negative.

Comment by jimrandomh on Preprint says R0=~5 (!) / infection fatality ratio=~0.1%. Thoughts? · 2020-03-20T17:59:38.827Z · score: 22 (9 votes) · LW · GW

tl;dr: Someone wrote buggy R code and rushed a preprint out the door without proofreading or sanity checking the numbers.

The main claim of the paper is this:

The total number of estimated laboratory–confirmed cases (i.e. cumulative cases) is 18913 (95% CrI: 16444–19705) while the actual numbers of reported laboratory–confirmed cases during our study period is 19559 as of February 11th, 2020. Moreover, we inferred the total number of COVID-19 infections (Figure S1). Our results indicate that the total number of infections (i.e. cumulative infections) is 1905526 (95%CrI: 1350283– 2655936)

So, they conclude that less than 1% of cases were detected. They claim 95% confidence that no more than 1.5% of cases were detected. They combine this with the (unstated) assumption that 100% of deaths were detected and reported, and that therefore the IFR is two orders of magnitude lower than is commonly believed. This is an extraordinary claim, which the paper doesn't even really acknowledge; they just sort of throw numbers out and fail to mention that their numbers are wildly different from everyone else's. Their input data is

the daily series of laboratory–confirmed COVID-19 cases and deaths  in Wuhan City and epidemiological data of Japanese evacuees from Wuhan City on board government–chartered flights

This is not a dataset which is capable of supporting such a conclusion. On top of that, the paper has other major signals of low quality. The paper is riddled with typos. And there's this bit:

Serial interval estimates of COVID-19 were derived from previous studies of nCov, indicating that it follows a gamma distribution with the mean and SD at 7.5 and 3.4 days, respectively, based on [14]

In this post I collected estimates of COVID-19's serial interval. 7.5 days was the chronologically first published estimate, was the highest estimate, and was an outlier with small sample size. Strangely, reference [14] does not point to the paper which estimated 7.5 days; that's reference 21, whereas reference 14 points to this paper which makes no mention of the serial interval at all.

Comment by jimrandomh on Is the Covid-19 crisis a good time for x-risk outreach? · 2020-03-20T00:13:56.022Z · score: 20 (8 votes) · LW · GW

Right now, most people are hyperfocused on COVID-19; this creates an obvious incentive for people to try to tie their pet issues to it, which I expect a variety of groups to try and which I expect to mostly backfire if tried in the short run. (See for example the receptiontthe WHO got when they tried to talk about stigma and discriminatio; people interpreted it as the output of an "always tie my pet issue to the topic du jour" algorithm and ridiculed then for it. Talking about AI risk in the current environment risks provoking the same reaction, because it probably would in fact be coming from a tie-my-pet-topic algorithm.

A month from now, however, will be a different matter. Once people start feeling like they have attention to spare, and have burned out on COVID-19 news, I expect them to be much more receptive to arguments about tail risk and to model-based extrapolation of the future than they were before.

Comment by jimrandomh on Covid-19 Points of Leverage, Travel Bans and Eradication · 2020-03-19T18:36:47.000Z · score: 10 (5 votes) · LW · GW

To start, the severity estimates that Joshua assumed were worst case and are implausible. The very alarmist Fergeson et al paper has much lower numbers than Joshua's [Joscha Bach's] claim that "20% will develop a severe case and need medical support to survive."

I believe the 20% figure comes from the WHO joint report which says

13.8% have severe disease (dyspnea, respiratory frequency ≥30/minute, blood oxygen saturation ≤93%, PaO2/FiO2 ratio <300, and/or lung infiltrates >50% of the lung field within 24-48 hours) and 6.1% are critical (respiratory failure, septic shock, and/or multiple organ dysfunction/failure).

There are a lot of modeling assumptions that go into this, and the true number is probably lower, but not so low as to invalidate Joscha's point.

Comment by jimrandomh on [UPDATED] COVID-19 cabin secondary attack rates on Diamond Princess · 2020-03-19T01:22:56.007Z · score: 15 (4 votes) · LW · GW

Thank you, this is exactly the sort of clever analysis I was hoping people would come up with when I wrote my post.

This site has floor-plan images of Diamond Princess cabins, from which we can make a few inferences about cabin occupancy. Most of the cabin layouts contain a single bed which fits two people, so two-person cabins will almost exclusively couples sharing a bed. If I assume the rate at which people in single-person cabins get infected (8%) is the rate of infection outside the cabin, and that the higher rate of infection in two-person cabins is caused entirely by within-cabin secondary transmission, then it looks like each person would have to infect their partner an average of 1.5 times each. This also tells us that the transmission rate between elderly couples sharing a bed is likely to be extremely high, and also that people in single-person cabins must be different in some way--perhaps they spent less time in the ship's common areas.

Three- and four-person cabins seem harder to interpret. These would originally have been couples with children, but there aren't many children aboard as of Feb 5th, and they probably moved people around to free up single cabins for extra-vulnerable people and for confirmed cases that they needed to isolate.

Comment by jimrandomh on COVID-19's Household Secondary Attack Rate Is Unknown · 2020-03-19T00:36:41.760Z · score: 2 (1 votes) · LW · GW

This paper analyzes specific incidents in which a group of one infected person plus some uninfected people sat down together, and some uninfected people got it. They find a secondary attack rate (from mostly non-household interactions) of 35%.

There are two big issues that prevent this paper from being used to draw good inferences about the household secondary attack rate. First, the incidents were found by specifically looking for superspreading events, and does not include any events where transmission didn't happen. And second, the events are single gatherings, whereas living with someone may involve many opportunities to get infected.

Comment by jimrandomh on Does the 14-month vaccine safety test make sense for COVID-19? · 2020-03-18T19:48:28.914Z · score: 11 (7 votes) · LW · GW

The main piece of data that would help answer this question is case-studies of past vaccines, whether they had safety problems and what those problems were, and when the problems manifested. Given that there's a new influenza vaccine every year, and I've never heard of any year's influenza vaccine being rejected on safety grounds, my guess is that 18 months is much too conservative.

Comment by jimrandomh on Ubiquitous Far-Ultraviolet Light Could Control the Spread of Covid-19 and Other Pandemics · 2020-03-18T19:09:02.539Z · score: 10 (2 votes) · LW · GW

The indentation of the table of contents is determined by the heading levels. It looks like you may have set some of the headings to "Heading 2" style and others to "Heading 3" style in Docs, then adjusted the font size to make them look the same. If you use Docs' heading format presets and use the same one for all the sections, they should be at the same indent level.

Comment by jimrandomh on Ubiquitous Far-Ultraviolet Light Could Control the Spread of Covid-19 and Other Pandemics · 2020-03-18T19:00:06.709Z · score: 2 (1 votes) · LW · GW

Unfortunately the LW codebase doesn't support multiple authors with edit access to the same post yet; we're working on this (as part of a broader overhaul of the post editor, which will allow Google Docs-style simultaneous editing), but it isn't ready yet. In the mean time, the easiest way to handle this is to make edits in a shared Google Doc, and have the primary author paste them in and save. (Copy-paste between the post editor and Google Docs should just work.)

Comment by jimrandomh on Ubiquitous Far-Ultraviolet Light Could Control the Spread of Covid-19 and Other Pandemics · 2020-03-18T18:29:14.517Z · score: 4 (2 votes) · LW · GW

(I added Roko to the metadata as a coauthor. Tagged coauthors are a beta-feature which currently can only be edited by moderators, since we haven't implemented the mechanics of having authors approve each other.)

Comment by jimrandomh on Good News: the Containment Measures are Working · 2020-03-17T16:24:47.215Z · score: 2 (1 votes) · LW · GW

In this post I collected papers which estimate the incubation period (time from exposure to symptom onset) and the serial interval (time from exposure to infecting the next person in the chain). Studies get varying results because they're done in different populations and have methodological differences, but find reasonably similar medians. A few of them also provide full distributions over incubation periods and serial intervals.

Comment by jimrandomh on Good News: the Containment Measures are Working · 2020-03-17T08:14:00.212Z · score: 8 (4 votes) · LW · GW

What does it mean for the future? That it takes about a week of a severe lockdown to switch from the exponential growth to linear, about two weeks to switch to leveling off, and three to four weeks to start seeing a meaningful decline.

This is because of the incubation period (3-14d) and the delay between people becoming symptomatic and getting tested. The reduction in transmissions is immediate, it just takes awhile to notice.

Comment by jimrandomh on COVID-19's Household Secondary Attack Rate Is Unknown · 2020-03-17T00:09:19.577Z · score: 15 (4 votes) · LW · GW

R0 is the number of people that each person will go on to infect, on average. R0 for COVID-19 is high compared to other common diseases, indicating high transmissibility.

I avoided stating a quantitative estimate of the attack rate because my confidence intervals are too wide to be useful. If I had to bet, I'd say 90% CI 15-85%, 50% CI 30-65%. I'm hoping people can gather weak evidence of various forms (secondary attack rates and R0s of other diseases, anecdotes in which household members do or don't get it, or in the best case a dataset with household memberships labelled).

Comment by jimrandomh on Will nCoV survivors suffer lasting disability at a high rate? · 2020-03-16T23:13:01.281Z · score: 13 (3 votes) · LW · GW

Relevant post by Sarah Constantin: COVID-19 Risks For Young People

Comment by jimrandomh on Could you save lives in your community by buying oxygen concentrators from Alibaba? · 2020-03-16T20:52:12.936Z · score: 8 (4 votes) · LW · GW

This isn't a question that can really be answered, because access to resources like RNs and places to isolate people is very local but the top-level post is about the effectiveness of oxygen concentrators in general.

That said, the Bay Area rationality community, at least, does have these things.

Comment by jimrandomh on A Significant Portion of COVID-19 Transmission Is Presymptomatic · 2020-03-15T04:56:25.720Z · score: 8 (4 votes) · LW · GW

Looks like I was about a day ahead of the curve. I wonder whether Elizabeth Cohen reads LessWrong? In any case, I'm glad the media is now making this more well known. That article is mostly based on the same papers as my post, but adds some other evidence, such as Sandra Ciesek's measurements of viral shedding,

Comment by jimrandomh on A Significant Portion of COVID-19 Transmission Is Presymptomatic · 2020-03-14T17:23:31.077Z · score: 6 (3 votes) · LW · GW

I found this article which makes that claim, and cites the WHO joint mission report. However, I can't find the claim (or the number "25%" used in any capacity) in the cited document at all. I suspect that the article mixed up percent of cases which are asymptomatic with the percent of transmissions which are from asymptomatic sources.

Comment by jimrandomh on A Significant Portion of COVID-19 Transmission Is Presymptomatic · 2020-03-14T17:02:32.946Z · score: 6 (4 votes) · LW · GW

Tapiwa Ganyani et al, the one with quantitative estimates of presymptomatic transmission, used data from Singapore up to Feb 26th and Tianjin up to Feb 27th. Both are cities which seem to have achieved containment over the relevant time period. I'm going to focus on Singapore, because information about what Singapore has been doing is easier to come by.

This article has a graph of Singapore's case counts over the relevant time period, and appears to show it as being contained (R<1) during the relevant time period. This paper estimates the latency between people becoming symptomatic and being isolated in Singapore, and finds that it's about 3 days for local cases as of Feb 26th, but longer on earlier dates. Their endpoint is "hospitalization or quarantine", but reading Singapore's FAQ, it sounds like they have a tiered system with two lesser levels of isolation that the paper doesn't mention: leave of absence (advice to isolate with no legal force) and stay-home notice (which has legal force against leaving the house, but only a non-binding advisory against having visitors). The lesser isolation tiers are for traced contacts, and would be effective at preventing asymptomatic transmission as well.

My impression from all this is that Singapore's measures would have driven symptomatic transmission down more than asymptomatic transmission, but substantially driven down both.

Comment by jimrandomh on A Significant Portion of COVID-19 Transmission Is Presymptomatic · 2020-03-14T07:05:53.780Z · score: 3 (2 votes) · LW · GW

When they identify a person with symptoms, they certainly isolate that person, but they also do contact tracing. Standard practice is to tell everyone who's interacted with an infected person to self-quarantine for 14 days, even if they aren't symptomatic. If that happens soon enough and is thorough enough, it can in principle prevent all presymptomatic transmission.

Comment by jimrandomh on A Significant Portion of COVID-19 Transmission Is Presymptomatic · 2020-03-14T06:22:07.307Z · score: 5 (3 votes) · LW · GW

Asked on Facebook crosspost: If it's transmitted by cough, how do asymptomatic people transmit it? Is it dependent on other diseases or allergies to provoke coughing?

None of the studies cited address the question of how presymptomatic transmission occurs, but my guess is that it's the same: respiratory droplets. People also emit droplets when they talk and breathe. There aren't as many and they don't travel as far as when they cough, but they're there.

Comment by jimrandomh on Will nCoV survivors suffer lasting disability at a high rate? · 2020-03-11T23:50:57.986Z · score: 25 (6 votes) · LW · GW

Acute respiratory distress syndrome (ARDS) occurs in about 20% of the subset of patients severe enough to be hospitalized, which are themselves the ~20% more-severe subset. This study finds 50% survival among patients with ARDS, and 91% survival among patients without. So, very approximately, the risk of death-or-ARDS is about twice as high as the risk of death.

Functional Disability 5 Years after Acute Respiratory Distress Syndrome tracked the outcomes of patients with ARDS from other sources, mostly pneumonia (not from COVID-19) but also sepsis (other infections), trauma, and other causes.

Main findings: ~10% died within 1 year, ~20% within 5 years. Of those who survived to 5-year followup, score on the SF-36 physical health survey was reduced 1 SD relative to age-matched controls. At 5-year follow-up, 77% of patients had returned to work, of which 94% of these patients returned to their original work.

Comment by jimrandomh on How useful are masks during an epidemic? · 2020-03-11T21:53:25.582Z · score: 18 (7 votes) · LW · GW

The majority of studies either compare two different kinds of masks to each other, in a hospital setting, which is interesting but not the main thing we want, which is a comparison between mask and no mask. There are also a few studies looking at households where the housemates of a person with influenza-like illness are randomly assigned to use masks (or not); these studies find masks are not effective, but also show low compliance. In a household setting, most of the variance in whether a household member gets infected is likely explained by vaccination, other sources of prior immunity, and kitchen hygiene; whereas when considering infections of coronavirus occurring in public, none of these are factors. All studies had problems with noncompliance, and confounding between compliance and other precautions (ie people who comply with masks wash their hands at rates.)

This study is interesting in that it effectively has a "placebo mask" arm. There were three arms: a no-intervention arm in which health care workers continued wearing whatever masks they did before (less often than in either intervention arm, but still a significant amount), an intervention arm where hospital workers are given reusable cloth masks which do not work, and an intervention arm in which they're given disposable medical masks. The disposable medical mask arm did best, the cloth-mask arm did worst (worse than the no-intervention arm, due to a combination of not using other masks and taking fewer non-mask precautions). Presumably, this was able to get past an IRB because the study authors didn't know how bad cloth masks are.

Compliance (defined as "mask wearing more than 70% of working hours") was 57% in both the cloth mask and medical groups, and 24% in the no-intervention group.

The majority of infections in the study were from rhinovirus, which is transmitted via aerosol and contact droplets. These are the same modes of transmission as SARS-CoV2, but in different proportions; rhinovirus causes sneezing, so it generates a lot of aerosol, whereas SARS-CoV2 doesn't and aerosol is believed to be responsible for only a small portion of its transmissions. Other diagnosed infections in the study were from hMPV and influenza B. Rhinovirus has a smaller diameter than SARS-CoV2 (30nm), so it's unlikely that mask aerosol penetration of rhinovirus is higher than that of SARS-CoV2. In particle penetration tests, the cloth masks were almost completely ineffective, and the medical masks had some effectiveness but much less than N95.

Compared to cloth masks, medical masks reduced clinical respiratory illness from 7.6 to 4.8%, laboratory-confirmed viral infection from 5.4 to 3.3%, and influenza-like illness from 2.3 to 0.2%.

Comment by jimrandomh on March Coronavirus Open Thread · 2020-03-10T18:37:00.496Z · score: 17 (7 votes) · LW · GW

Legally speak, yes they would. Practically speaking, however, the FDA has no enforcement power over secret programs in the intelligence community.

I think a lot of people are seriously overestimating the FDA's actual power, and that's causing pretty severe problems. Consider for example this tweet (and a long series like it) by the mayor of NYC, begging the FDA for approvals. While there is no legal precedent to refer to, it's extremely implausible that the FDA could ever get or enforce a judgment of the city of New York for actions taken during a state of emergency, when the FDA itself caused that emergency with culpable negligence.

Comment by jimrandomh on March Coronavirus Open Thread · 2020-03-10T04:00:41.191Z · score: 4 (2 votes) · LW · GW

In principle, with enough resources, multiple vaccines could be tested this way in parallel. Not that there are that many vaccine candidates to try, as far as I know; but if there were some software that bulk-generated candidate molecules, it could be done, in principle. The limiting input is mobilized resources, not time.

Comment by jimrandomh on March Coronavirus Open Thread · 2020-03-09T21:23:41.425Z · score: 10 (3 votes) · LW · GW

Health care settings are likely to already be well supplied, and to be picky about which kind of hand sanitizer they use (even if it's just about getting an internal approval).

Comment by jimrandomh on How long does SARS-CoV-2 survive on copper surfaces · 2020-03-09T21:12:26.010Z · score: 8 (4 votes) · LW · GW

Your stick would be significantly better if you used a uniform cylinder, rather than a piece of natural wood. The uneven shape means that the copper tape has a lot of crevasses, which can get dirt in them that's hard to clean out. If the copper has dirt on top of it, it's not going to inactivate anything that's on top of the dirt.

Comment by jimrandomh on March Coronavirus Open Thread · 2020-03-09T21:10:01.629Z · score: 4 (2 votes) · LW · GW

Something is weird about that 3-10% secondary attack rate number. The study isn't published yet, so I don't know what exactly they're measuring, but I'm pretty confident that people who share a household and hug each other will transmit at much greater than 10% probability.

Comment by jimrandomh on March Coronavirus Open Thread · 2020-03-09T21:07:55.705Z · score: 2 (1 votes) · LW · GW

The "terminally ill" bit was part of the (probably false) rumor that I heard. Preexisting illness definitely screws with the safety-testing aspect, but there are also illnesses don't interfere with the efficacy testing. I agree that a competent agency uses healthy people for this if they could. If experimenting on healthy people wasn't possible or worth it, one possibility would be to do an efficacy trial on unhealthy people and a safety study on animals in parallel.

Comment by jimrandomh on The Heckler's Veto Is Also Subject to the Unilateralist's Curse · 2020-03-09T08:38:22.402Z · score: 24 (7 votes) · LW · GW

It occurs to me that a karma system (such as that used on this website) has the potential to be an adequate check against the unilateralist's curse as described by Bostrom et al. if we assume that the penalty applied to downvoted posts is sufficient to prevent the harm of the putative infohazard.

I think it provides feedback about whether a post was infohazardous or otherwise bad to post, but for many types of infohazard it pretty clearly doesn't prevent them from causing harm; doxxing, for example, is not so easily undone. Luckily most things are small and iterated, and people learn from the scores on each others' posts, so voting does significantly reduce the unilateralist's curse problem.

There can be circumstances where experts can see that something is an infohazard, while laypeople can't; in that case, voting only works if the experts explain their reasoning in addition to downvoting. Explaining one's reasoning under those circumstances looks very similar to trying to exercise a heckler's veto. In that case votes on the explanation are informative about whether the original post was an infohazard, but things get hard to interpret.

Comment by jimrandomh on March Coronavirus Open Thread · 2020-03-09T06:52:57.832Z · score: 36 (13 votes) · LW · GW

If this news article is accurate, masks will not be scarce for much longer. That article claims that China is now producing masks at 116M/day, a 12x increase compared to the start of February (5 weeks ago), and that they will export them. This is in addition to mask production in other countries.

I  am not sure whether, when combined with production in other countries, this satisfies the entire world demand. But masks aren't complicated objects and aren't made of scarce materials, and this is pretty strong evidence that production can be scaled up even further, if necessary.

In a few weeks, a number of public figures may find themselves doing an awkward about-face from "masks don't work and no one should wear them" to "masks do work and they are mandatory".

(If you are able to buy masks for less than $1/each through ordinary channels, it means the shortage has abated, and you can buy them without worrying about depriving health care workers of those supplies, but you shouldn't stock up on more than you need in the short term until the price has been low for at least a few weeks.)

Comment by jimrandomh on March Coronavirus Open Thread · 2020-03-09T06:49:36.379Z · score: 28 (11 votes) · LW · GW

I heard a rumor of someone in the Bay area claiming to work in the intelligence community, to be terminally ill, and to have received an experimental COVID-19 vaccine. I think this rumor is false with respect to the specific person, but do note that "military officers with preexisting terminal illnesses who volunteer" is a group that may actually exist, and that at least one drug company claims to have shipped vaccines for a phase 1 trial on Feb 24.

This raises the question: if you're well resourced, desperate, competent, and in possession of expendable military volunteers, how long does development for a vaccine actually take?

Given a candidate vaccine, you need to do three things: find out if confers immunity (and how much immunity), find out if it causes side effects severe enough to not be worth it, and scale up production.

All three of these can be done in parallel. If you have expendable volunteers, you don't need to start with an animal model; you can just give them the vaccine, and see whether they suffer side effects. Testing efficacy can be done in parallel, with the same volunteers, and takes about three weeks--you give the vaccine, wait a week, expose to virus, then wait in quarantine for two weeks.

If you're unlucky, this kills all the test subjects. If you're average-lucky, your test subjects get COVID-19 and die at the same rate as people die of that. If you're lucky, you have solid evidence of effectiveness and moderate evidence of safety. Not as much evidence of safety as you want, and certainly not up to the FDA's traditional standards, but good enough that medical workers in affected areas would seriously consider it.

Maybe it's optimistic, but in my model of the world, there are islands of competence within the intelligence community which do things like this. In most worlds, this project fails, and the public never hears about it. The President, on the other hand, does hear about it. He hears about many vaccine projects with different timelines and different chances of success, and they all blend together. He says on the news that a vaccine will be ready in several weeks, and everyone--the NIAID, the press, the public--mocks him for the mistake, because they don't know about the secret trial. Or maybe he never heard of anything like that, and is just confused; this is not something we are likely to ever know.

Coronavirus could spread unabated, or it could be killed by quarantines, or it could spread but lose its lethality to a new treatment, or we could be surprised by an unprecedentedly fast vaccine. Let us retain our flexibility, and keep our prediction confidence intervals wide.

Comment by jimrandomh on It's Time To Stop Dancing · 2020-03-09T03:55:37.826Z · score: 9 (5 votes) · LW · GW

Thank you. This was the right call.

Comment by jimrandomh on Ineffective Response to COVID-19 and Risk Compensation · 2020-03-09T00:33:53.674Z · score: 6 (3 votes) · LW · GW

That paper (which I notice you're first author on) is pretty good and you might want to post it as a top-level post. Note that you estimate handwashing optimistically reduces transmission by 50%. This paper estimated an R0 in Wuhan of 3.86 prior to social distancing measures, so if the situation in other cities is similar, then high compliance with hand-washing would only cover about half of the required reduction, with the rest left to other measures such as reduction in gatherings and travel.

Comment by jimrandomh on The Lens, Progerias and Polycausality · 2020-03-08T22:52:02.445Z · score: 6 (3 votes) · LW · GW

I hadn't heard the transposon theory of aging before. If true, that would explain why aging hasn't been selected out by evolution: the transposons themselves have evolved, under different incentives than their host genome's incentives.

Comment by jimrandomh on The Lens, Progerias and Polycausality · 2020-03-08T19:10:42.351Z · score: 8 (4 votes) · LW · GW

This mostly makes sense to me; since DNA is at the root of many different regulatory mechanisms at once, cumulative DNA damage would be expected to gradually dysregulate everything. Since cell-count is one of the things being regulated, this predicts that DNA damage causes a superset of the symptoms of cell loss. And since DNA repair is itself one of the things being replicated, this would predict that DNA damage grows super-linearly.

(Interestingly, this implies that the safety screening done on food additives and other chemicals is more valuable than I previously thought; they look for DNA damage, on the theory that DNA damage leads to cancer.)

What's still confusing to me, though, is how little variance there is in the timeline of aging symptoms. This would seem to imply that there is something upstream of DNA damage and/or of cell loss, which does not behave like DNA-damage-causing-more-DNA-damage, but rather behaves more like lens fibers. I wonder what mechanism that might be?

(Also, let me just say that I really appreciate this sequence. While there is a fair amount of down-in-the-details biology work on aging, high-level conceptual explanations like this have been in short supply. I expect this sequence to meaningfully impact the number of people who wind up doing in-the-details work, and the quality of the targeting of that work.)

Comment by jimrandomh on Why would panic during this coronavirus pandemic be a bad thing? · 2020-03-08T17:50:24.924Z · score: 6 (3 votes) · LW · GW

The main way in which panic causes damage during outbreaks is from people breaking quarantine to flee affected areas, and bringing the disease with them. This may be a problem later, when more areas have travel restrictions, but it isn't a problem if it happens right now. So I expect that early panic is better than late panic.

Comment by jimrandomh on Ignoring Country Cohorts · 2020-03-08T09:07:52.932Z · score: 10 (6 votes) · LW · GW

Note that the graphs on the "first 60 days" tab of the site you linked to, are on a log scale. The slope on that scale says something interesting, but it may not be what you think.

Decreasing slope on a log-scale plot means R0 has decreased. R0, the virus's basic reproductive number, is the average number of people that a given infected person will go on to infect. If R0 is greater than 1, the epidemic grows; if it's below 1, then the epidemic shrinks. Public health measures decrease R0. For example, if closing public transit would prevent half of all transmissions, then it would reduce R0 by half.

As more measures like social distancing and drive-through testing centers are added, they decrease R0 further. Since the cheapest measures are done first, each successive measure costs more; lowering R0 can't be done without limit, because eventually we run out of mitigations we can afford. If the mitigations are enough to get R0 to <1, then the epidemic can be contained. If we can't get R0 to <1, then the mitigations buy time and spread cases out, without significantly affecting the eventual number of cases.

If the epidemic grows to a large fraction of the population, then the fact that recovered patients are immune will itself lower R0, putting containment back within range of available mitigations. This is the point where the growth would stop.

So, the all-important question is: Can countries get R0<1, before they've emptied their toolkit? And, will they have to pay extreme costs (like China shutting down all industry) in order to do so?

This paper looked at Wuhan, and found that the extreme measures taken there lowered R0 from 3.86 to 0.32. This is good news, because it suggests that the measures taken in Wuhan were stronger than necessary; they prevented ~11/12ths of transmissions, when they only needed to prevent ~3/4ths. This is good news, because most countries can't implement measures as strong as Wuhan's; knowing that Wuhan's measures were stronger than necessary means that containing outbreaks might be feasible.

If a country has R0<1, then the number of new cases per day will decrease, after a time delay about equal to the incubation period. Unfortunately, that's not what we're seeing in any of the places where SARS-CoV-2 has taken hold. What we see is a decreasing slope on a log scale - an indication that R0 has been reduced - but not an indication that it has been reduced to less than 1. However, it's still quite early, test-kit and mask production has not yet caught up with demand, and strategies are still being refined, so there is hope.

Comment by jimrandomh on Credibility of the CDC on SARS-CoV-2 · 2020-03-08T05:32:38.886Z · score: 59 (28 votes) · LW · GW

Addendum: A whistleblower claims that CDC wanted to advise elderly and fragile people to not fly on commercial airlines, but removed this advice at the White House's direction.

Where the CDC and White House are in conflict, I believe the CDC is more credible (and I believe this is consensus); however, this looks like a clear-cut case where the CDC's political situation forced it to be less honest and understate risk.

Comment by jimrandomh on Credibility of the CDC on SARS-CoV-2 · 2020-03-07T21:19:52.748Z · score: 15 (9 votes) · LW · GW

Note to downvoters: While I disagree with this comment, it expresses a real concern and opens a conversation that does very much need to happen. So I've upvoted it back out of the negatives, and think it should probably stay positive.

Comment by jimrandomh on Credibility of the CDC on SARS-CoV-2 · 2020-03-07T20:27:23.510Z · score: 6 (3 votes) · LW · GW

This is certainly possible, and it will never be possible to fully rule out second exposures in cases like this. But note that the 19- and 27-day outliers were not included in the data used by the linked paper that estimated a >14day right tail, and I think it's unlikely for untraced second exposures to have influenced its conclusion.

Comment by jimrandomh on Credibility of the CDC on SARS-CoV-2 · 2020-03-07T20:15:38.896Z · score: 113 (30 votes) · LW · GW

You're wrong about this. Trust in the CDC is not a single-variable scale and not a generically useful resource. Trust in the CDC is a mix of peoples' estimation of the CDC's competence, and their estimation of whether the CDC is biased towards under-response or over-response. It is severely harmful for people to over-estimate the CDC's competence, or to fail to recognize that the CDC is biased towards under-response.

Having previously over-estimated CDC's competence caused many parties which could have been bypassing the CDC to create and deploy tests, to fail to respond in time. I expect that decision-makers currently relying on the CDC's competence will implement distancing measures and ban gatherings much too late.

The main reason we might want people to over-estimate the CDC's competence is that this trust could be used to solve coordination problems. However, the coordination problems that CDC could plausibly solve--closing airports, banning public gatherings, and implementing quarantines--are problems that it solves using legal power, not using generic community trust. To the extent that community trust is required to implement such measures, knowing that the CDC has been consistently biased towards under-response will make it easier, to a greater degree than knowing that they've been incompetent will make it harder.

My evaluation is that reducing trust in the CDC has net-positive consequences. But note that, separately, I don't think an evaluation of this depth is typically required before truthfully speaking about an organization's credibility. I expect that nearly all of the time, when trading off between speaking truth and empowering an institution, speaking truth is the correct move, and those who think otherwise will be mistaken.

Comment by jimrandomh on How are people tracking confirmed Coronavirus cases / Coronavirus deaths? · 2020-03-07T06:23:19.105Z · score: 35 (7 votes) · LW · GW

All of the data on that dashboard is in this GitHub repository, by the creators of the dashboard. You probably want this folder, which has a CSV file for each day, added once per day, with all the locations and case counts.

Comment by jimrandomh on Effectiveness of Fever-Screening Will Decline · 2020-03-07T04:30:50.727Z · score: 2 (1 votes) · LW · GW

If I follow your argument the fever screening will get those infected with virus that tend to cause a higher fever than other virus. As we control those cases the others go on to reproduce and so the population of the virus then mutates to not causing the fever. Is that the basis position?

Yes.

If so, that seems to suggest how each person reacts to the infection is the same rather than the virus being the same but people reacting to it differently. If so, we will miss those who don't respond to the infection with a fever (are as strong of a fever) but that should not create any environmental pressure to select for a low fever version of the virus.

Yes. The relevant thing is how much of the variance in fever is caused by mutations in the virus, versus being caused by differences between people. If people vary more in whether they have a fever than the virus varies in whether it causes a fever, this would weaken the evolutionary pressure; if they vary enough more, then my prediction of declining fever-screening effectiveness will be wrong.

Comment by jimrandomh on Credibility of the CDC on SARS-CoV-2 · 2020-03-07T03:10:43.874Z · score: 16 (7 votes) · LW · GW

This section is kind of confusing, and I have tweaked the wording a little bit to try to be clearer. The reason for the confusion is that there are two nested distributions here.

The first is that when a bunch of people get infected, they have different incubation periods; some of them start showing symptoms more quickly than others. This is what the 99th percentile refers to. This makes us uncertain about the incubation period that a particular person will have, but it is not a confidence interval; if we learned how long the incubation periods were for a very large number of people, it wouldn't make the 99th-percentile person's incubation period any closer to the mean incubation period.

The second distribution is our uncertainty about the first distribution; we don't know exactly what fraction of people will have extra-long incubation periods, or how long those periods will be--but we would if we observed enough people. This uncertainty is what the 9.7-17.2, 10.9-20.6, and 12.6-32.2 ranges are referring to.

Comment by jimrandomh on Effectiveness of Fever-Screening Will Decline · 2020-03-07T03:00:07.099Z · score: 11 (3 votes) · LW · GW

I re-read the studies originally included in this post looking for data relating illness severity to fever. Two of the studies compared the rate of fever in ICU vs non-ICU COVID-19 patients. This one finds 13/13 in ICU and 27/28 in non-ICU have fever; this one finds 36/36 in ICU and 100/102 non-ICU had fever. This study broke down its patients into a hospitalized subset in which 6/6 had fever and a non-hospitals subset in which 58.3% had fever; I had mis-read this one on the first pass when writing the post, and wrote down the percent with fever in the hospitalized subset (100%).

This does seem to be consistent with fever being more common among the subset of patients which are severe enough to be hospitalized. I have edited the post to reflect this interpretation, and corrected the one study that was mis-extracted; you can see the old version of the post here. This weakens my belief that the rate of fever at onset has already declined, though I still think it is somewhat likely, and I still expect it to decline in the future.