Astral Codex Ten Podcast

https://slatestarcodex.com/2020/04/10/coronalinks-4-10-second-derivative/ The second derivative is the rate of growth of the rate of growth. Over the past few weeks, the second derivative of total coronavirus cases switched from positive (typical of exponential growth) to zero or negative (typical of linear or sublinear growth) in most European countries. Over the past few days, it switched from positive to zero/negative in the United States and the world as a whole. These are graphs of the rate of growth – notice how they go from shooting upward to being basically horizontal or downward-sloping (source). This graph shows the numbers a little differently, (source), but you can see the same process going on in individual US cities It would be premature to say we're now winning the war on coronavirus. But we've stopped actively losing ground. If we were going to win, our first sign would be something like this. Current containment strategies are working. As before, feel free to treat this as an open thread for all coronavirus-related issues. Everything here is speculative and not intended as medical advice. The Bat Flu SSC reader Trevor Klee has a great article on why humans keep getting diseases from bats (eg Ebola, SARS, Marburg virus, Nipah virus, coronavirus). He explains that because bats expend so much energy flying, they run higher body temperatures than other mammals, which degrades their DNA. Their DNA is such a mess that the usual immune system strategy of targeting suspicious DNA doesn't work, so they accept constant low-grade infection with a bunch of viruses as a cost of doing business. Sometimes those viruses cross to humans, and then we get another bat-borne disease.

https://slatestarcodex.com/2020/04/08/2019-predictions-calibration-results/ At the beginning of every year, I make predictions. At the end of every year, I score them (this year I'm very late). Here are 2014, 2015, 2016, 2017, and 2018. And here are the predictions I made for 2019. Strikethrough'd are false. Intact are true. Italicized are getting thrown out because I can't decide if they're true or not. All of these judgments were as of December 31 2019, not as of now. Please don't complain that 50% predictions don't mean anything; I know this is true but there are some things I'm genuinely 50-50 unsure of. Some predictions are redacted because they involve my private life or the lives of people close to me. A few that started off redacted stopped being secret; I've put those in [brackets].

https://slatestarcodex.com/2020/04/07/never-tell-me-the-odds-ratio/ [Epistemic status: low confidence, someone tell me if the math is off. Title was stolen from an old Less Wrong post that seems to have disappeared – let me know if it's yours and I'll give you credit] I almost screwed up yesterday's journal club. The study reported an odds ratio of 2.9 for antidepressants. Even though I knew odds ratios are terrible and you should never trust your intuitive impression of them, I still mentally filed this away as "sounds like a really big effect". This time I was saved by Chen's How Big is a Big Odds Ratio? Interpreting the Magnitudes of Odds Ratios in Epidemiological Studies, which explains how to convert ORs into effect sizes. Colored highlights are mine. I have followed the usual statistical practice of interpreting effect sizes of 0.2 as "small", of 0.5 as "moderate", and 0.8 as "large", but feeling guilty about it.

https://slatestarcodex.com/2020/04/06/sscjc-real-world-depression-measurement/ The largest non-pharma antidepressant trial ever conducted just confirmed what we already knew: scientists love naming things after pandas. We already had PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus) and PANDA (Proton ANnhilator At DArmstadt). But the latest in this pandemic of panda pandering is the PANDA (Prescribing ANtiDepressants Appropriately) Study. A group of British scientists followed 655 complicated patients who received either placebo or the antidepressant sertraline (Zoloft®). The PANDA trial was unique in two ways. First, as mentioned, it was the largest ever trial for a single antidepressant not funded by a pharmaceutical company. Second, it was designed to mimic "the real world" as closely as possible. In most antidepressant trials, researchers wait to gather the perfect patients: people who definitely have depression and definitely don't have anything else. Then they get top psychiatrists to carefully evaluate each patient, monitor the way they take the medication, and exhaustively test every aspect of their progress with complicated questionnaires. PANDA looked for normal people going to their GP's (US English: PCP's) office, with all of the mishmash of problems and comorbidities that implies.

https://slatestarcodex.com/2020/04/01/book-review-the-precipice/ I. It is a well known fact that the gods hate prophets. False prophets they punish only with ridicule. It's the true prophets who have to watch out. The gods find some way to make their words come true in the most ironic way possible, the one where knowing the future just makes things worse. The Oracle of Delphi told Croesus he would destroy a great empire, but when he rode out to battle, the empire he destroyed was his own. Zechariah predicted the Israelites would rebel against God; they did so by killing His prophet Zechariah. Jocasta heard a prediction that she would marry her infant son Oedipus, so she left him to die on a mountainside – ensuring neither of them recognized each other when he came of age. Unfortunately for him, Oxford philosopher Toby Ord is a true prophet. He spent years writing his magnum opus The Precipice, warning that humankind was unprepared for various global disasters like pandemics and economic collapses. You can guess what happened next. His book came out March 3, 2020, in the middle of a global pandemic and economic collapse. He couldn't go on tour to promote it, on account of the pandemic. Nobody was buying books anyway, on account of the economic collapse. All the newspapers and journals and so on that would usually cover an exciting new book were busy covering the pandemic and economic collapse instead. The score is still gods one zillion, prophets zero. So Ord's PR person asked me to help spread the word, and here we are.

https://slatestarcodex.com/2020/03/31/ssc-journal-club-macintyre-on-cloth-masks/ Content warning: this is a complicated analysis of something people care about a lot right now. I'm not confident in my analysis, the post comes to no clear conclusion and there are no easy answers about how to proceed. If I see this on Twitter with some headline about it DESTROYING somebody, I am going to be so mad.] The New York Times says that It's Time To Make Your Own Face Mask. But MacIntyre et al (2015) says it isn't. The surgical masks used in hospitals are made out of non-woven fabrics that are pretty different from anything you have at home. But in some developing countries, health care workers instead use masks made of normal cloth. Laboratory tests find that improvised cloth masks block 60 – 80% of virus particles. Respirators and real surgical masks block 95%+, but 60-80% still seems better than nothing. And most of the masks ordinary people wear in Asian countries are cloth, and they seem to do pretty well. So there's some circumstantial evidence that these cloth masks might be helpful. Most experts in the early 2000s agreed that these masks were probably better than nothing. In 2015, an Australian team set out to prove it with a randomized controlled trial.

https://slatestarcodex.com/2020/03/30/legal-systems-very-different-from-ours-because-i-just-made-them-up/ [with apologies to the real Legal Systems Very Different From Ours. See also the List Of Fictional Drugs Banned By The FDA] I. The Clamzorians are animists. They believe every rock and tree and river has its own spirit. And those spirits are legal people. This on its own is not unusual – even New Zealand gives rivers legal personhood. But in Clamzoria, if a flood destroys your home, you sue the river. If you win, then the river is in debt to you. The government can assign a guardian to the river to force it to pay off its debts, and that guardian gets temporary custody of all the river's property. He or she can collect a toll from boats, sell water to reservoirs, and charge rent to hydroelectric dams. Once the river has paid off its debt, the guardian is discharged, and the river becomes free to use once again. Clamzorian precedent governs when you may or may not sue objects. If you swim in the freezing river in the dead of winter, and catch cold, that's on you. But if a hurricane destroys your property, you can absolutely sue the wind for damages, and collect from windmills. Suits against earthquakes, volcanoes, and the like are dead common. Suits against diseases happen occasionally. Sometimes someone will sue something even more abstract – a custom, an emotion, a concept.

https://slatestarcodex.com/2020/03/27/coronalinks-3-27-20/ The United States now has more coronavirus cases than any other country, including China, marking a new stage in the epidemic. As before, feel free to treat this as an open thread for all coronavirus-related issues. Everything here is speculative and not intended as medical advice. Hammer and dance Most of the smart people I've been reading have converged on something like the ideas expressed in The Hammer And The Dance – see this Less Wrong post for more. Summary: Asian countries have managed to control the pandemic through mass testing, contact tracing, and travel bans, without economic shutdown. The West lost the chance for a clean win when it bungled its first month of response, but it can still recover its footing. We need a medium-term national shutdown to arrest the spread of the virus until authorities can get their act together – manufacture lots of tests and face masks, create a testing infrastructure, come up with policies for how to respond when people test positive, distribute the face masks to everyone, etc. With a lot of work, we can manage that in a month or so. After that, we can relax the national shutdown, start over with a clean slate, and pursue the Asian-style containment strategy we should have been doing since the beginning.

https://slatestarcodex.com/2020/03/23/face-masks-much-more-than-you-wanted-to-know/ There's been recent controversy about the use of face masks for protection against coronavirus. Mainstream sources, including the CDC and most of the media say masks are likely useless and not recommended. They've recently been challenged, for example by Professor Zeynep Tufekci in the New York Times and by Jim and Elizabeth on Less Wrong. There was also some debate in the comment section here last week, so I promised I'd look into it in more depth. As far as I can tell, both sides agree on some points. They agree that N95 respirators, when properly used by trained professionals, help prevent the wearer from getting infected. They agree that surgical masks help prevent sick people from infecting others. Since many sick people don't know they are sick, in an ideal world with unlimited mask supplies everyone would wear surgical masks just to prevent themselves from spreading disease. They also agree that there's currently a shortage of both surgical masks and respirators, so for altruistic reasons people should avoid hoarding them and give healthcare workers first dibs.

https://slatestarcodex.com/2020/03/19/coronalinks-3-19-20/ As before, feel free to treat this as an open thread for all coronavirus-related issues. Everything here is speculative and not intended as medical advice. How many real cases? As of today, the US has almost 10,000 official cases. How many real cases per official case? One epidemiologist says 8x. In this US News article, scientists estimate 9000 true cases back when the official count was 600, suggesting 15x, and BBC estimates 10,000 real cases in the UK to 500 official ones, suggesting 20x. A study in Science (article, paper) estimates 86% are undetected, for about 7x. So it seems like most people are converging around 5 – 20. Probably this number is different in every country, depending on their test rates. You're probably all already following the map of cases per country, but you can supplement with this map of how many tests each country is running per million people (h/t curryeater259 from the subreddit) What about the evidence from famous people? If only 100,000 Americans are infected, it's pretty weird that it would hit both Tom Hanks and Idris Elba (also, Tormund from Game of Thrones). The Atlantic makes this case more formally. Given that Iran's vice-president is affected, what are the chances that only 1/12,000 of Iranians had the virus? Some people calculated it out and found that hundreds of thousands of Iranians must be affected for the prevalence among politicians to make sense, suggesting ratios of 100x or even 1000x.