

Astral Codex Ten Podcast
Jeremiah
The official audio version of Astral Codex Ten, with an archive of posts from Slate Star Codex. It's just me reading Scott Alexander's blog posts.
Episodes
Mentioned books

Mar 4, 2023 • 47min
Grading My 2018 Predictions For 2023
https://astralcodexten.substack.com/p/grading-my-2018-predictions-for-2023 To celebrate the fifth anniversary of my old blog, in 2018, I made some predictions about what the next five years would be like. This was a different experience than my other predictions. Predicting five years out doesn't feel five times harder than predicting one year out. It feels fifty times harder. Not a lot of genuinely new trends can surface in one year; you're limited to a few basic questions on how the current plotlines will end. But five years feels like you're really predicting "the future". Things felt so fuzzy that I (partly) abandoned my usual clear-resolution probabilistic predictions for total guesses.

Feb 18, 2023 • 27min
Declining Sperm Count: Much More Than You Wanted To Know
https://astralcodexten.substack.com/p/declining-sperm-count-much-more-than Is Sperm Count Declining? People say it is. Levine et al 2017 looks at 185 studies of 42935 men between 1973 and 2011, and concludes that average sperm count declined from 99 million sperm/ml at the beginning of the period to 47 million today. Levine et al 2022 expands the previous analysis to 223 studies and 57,168 men, including research from the developing world. It finds about the same thing. Source: Figure 3 here The “et al” includes Dr. Shanna Swan, a professor of public health who has taken the results public in the ominously-named Count Down: How Our Modern World Is Altering Male and Female Reproductive Development, Threatening Sperm Counts, and Imperiling the Future of the Human Race. Is Declining Sperm Count Really "Imperiling The Future Of The Human Race”? Swan’s point is that if sperm counts get too low, presumably it will be hard to have babies (though IVF should still work). How long do we have? This graph (source) shows pregnancy rate by sperm count per artificial insemination cycle. It seems to plateau around 30 million. An average ejaculation is 3 ml, so total sperm count is 3x sperm/ml. Since sperm/ml has gone down from 99 million to 47 million, total count has gone down from ~300 million to ~150 million. 150 million is still much more than 30 million, but sperm count seems to have a wide distribution, so it’s possible that some of the bottom end of the distribution is being pushed over the line where it has fertility implications. But Willy Chertman has a long analysis of fertility trends here, and concludes that there’s no sign of a biological decline. Either the sperm count distribution isn’t wide enough to push a substantial number of people below the 30 million bar, or something else is wrong with the theory. Levine et al model the sperm decline as linear. If they’re right, we have about 10 - 20 more years before the median reaches the plateau’s edge where fertility decreases, and about 10 years after that before it reaches zero. Developing countries might have a little longer. It feels wrong to me to model this linearly, although I can’t explain exactly why besides “it means sperm will reach precisely 0 in thirty years, which is surely false”. The authors don’t seem to be too attached to linearity, saying that “Adding a quadratic or cubic function of year to meta-regression model did not substantially change the association between year and SC or improve the model fit”. Still, the 2022 meta-analysis found that the trend was, if anything, speeding up with time, so it doesn’t seem to be obviously sublinear.

Feb 17, 2023 • 20min
Trying Again On Fideism
https://astralcodexten.substack.com/p/trying-again-on-fideism [apologies for an issue encountered when sending out this post; some of you may have gotten it twice] Thanks to Chris Kavanagh, who wrote an extremely kind and reasonable comment in response to my Contra Kavanagh on Fideism and made me feel bad for yelling at him. I’m sorry for my tone, even though I'm never going to get a proper beef at this rate. Now that I'm calmed down, do I disagree with anything I wrote when I was angrier?

Feb 15, 2023 • 19min
Contra Kavanagh On Fideism
https://astralcodexten.substack.com/p/contra-kavanaugh-on-fideism I. I’ve been looking into the world of YouTube streamers; if you want to make it big, you need to have a beef with some other online celebrity. Fine; I choose Chris Kavanagh, who tweeted about me recently:

Feb 15, 2023 • 16min
Ro-mantic Monday 2/13/23
https://astralcodexten.substack.com/p/ro-mantic-monday-21323 In honor of Valentine’s Day, this installment of Mantic Monday will focus on attempted clever engineering solutions to romance. We’ll start with the usual prediction markets, then move on to other types of algorithmic and financial schemes. Normal content will resume next time around.

Feb 13, 2023 • 41min
Links For February 2023
https://astralcodexten.substack.com/p/links-for-february-2023 [Remember, I haven’t independently verified each link. On average, commenters will end up spotting evidence that around two or three of the links in each links post are wrong or misleading. I correct these as I see them, and will highlight important corrections later, but I can’t guarantee I will have caught them all by the time you read this.]

Feb 7, 2023 • 16min
Crowds Are Wise (And One's A Crowd)
https://astralcodexten.substack.com/p/crowds-are-wise-and-ones-a-crowd The long road to Moscow The “wisdom of crowds” hypothesis claims that the average of many guesses is better than a single guess. Ask one person to guess how much a cow weighs, and they’ll be off by some amount. Ask a hundred people and take the average of their answers, and you’ll be off by less. I was intrigued by a claim in this book review that: You can play “wisdom of crowds” in single-player mode. Say you want to know the weight of a cow. Then take a guess. Now throw your guess out of the window, and take another guess. Finally, compute the average of your two guesses. The claim is that this average is better than your individual guesses. This is spooky. We talk a lot about how to make accurate predictions here - and you can improve your accuracy on anything just by guessing twice and averaging, no additional knowledge required? It’s like God has handed us a creepy cow-weight oracle. I wanted to test this myself, so I included some relevant questions in last year’s ACX Survey:

4 snips
Feb 7, 2023 • 20min
Mostly Skeptical Thoughts On The Chatbot Propaganda Apocalypse
https://astralcodexten.substack.com/p/mostly-skeptical-thoughts-on-the People worry about chatbot propaganda. The simplest concern is that you could make chatbots write disinformation at scale. This has created a cottage industry of AI Trust And Safety people making sure their chatbot will never write arguments against COVID vaccines under any circumstances, and a secondary industry of journalists writing stories about how they overcame these safeguards and made the chatbots write arguments against COVID vaccines. But Alex Berenson already writes arguments against COVID vaccines. He’s very good at it, much better than I expect chatbots to be for many years. Most people either haven’t read them, or have incidentally come across one or two things from his years-long corpus. The limiting factor on your exposure to arguments against COVID vaccines isn’t the existence of arguments against COVID vaccines. It’s the degree to which the combination of the media’s coverage decisions and your viewing habits causes you to see those arguments. A million mechanical Berensons churning out a million times the output wouldn’t affect that; even one Berenson already churns out more than most people ever read.

Feb 3, 2023 • 3min
Book Review Contest Rules 2023
Basically the same as 2022 - this is just a reminder to start working on entries https://astralcodexten.substack.com/p/book-review-contest-rules-2023 Sure, this seemed to go well last the last few times, let's do it again. Write a review of a book. Any book you like - most past winners have been nonfiction, but maybe you can change that! There’s no official word count requirement, but previous finalists and winners were often between 2,000 and 10,000 words. There’s no official recommended style, but check the style of last year’s finalists and winners or my ACX book reviews (1, 2, 3) if you need inspiration. Please limit yourself to one entry per person or team. Then send me your review through this Google Form. The form will ask for your name, email, the title of the book, and a link to a Google Doc. The Google Doc should have your review exactly as you want me to post it if you’re a finalist. DON’T INCLUDE YOUR NAME OR ANY HINT ABOUT YOUR IDENTITY IN THE GOOGLE DOC ITSELF, ONLY IN THE FORM. I want to make this contest as blinded as possible, so I’m going to hide that column in the form immediately and try to judge your docs on their merit. (does this mean you can’t say something like “This book about war reminded me of my own experiences as a soldier” because that gives a hint about your identity? My rule of thumb is - if I don’t know who you are, and the average ACX reader doesn’t know who you are, you’re fine. I just want to prevent my friends or Internet semi-famous people from getting an advantage. If you’re in one of those categories and think your personal experience would give it away, please don’t write about your personal experience.) PLEASE MAKE SURE THE GOOGLE DOC IS UNLOCKED AND I CAN READ IT. By default, nobody can read Google Docs except the original author. You’ll have to go to Share, then on the bottom of the popup click on “Restricted” and change to “Anyone with the link”. If you send me a document I can’t read, I will probably disqualify you, sorry. First prize will get at least $2,500, second prize at least $1,000, third prize at least $500; I might increase these numbers later on. All winners and finalists will get free publicity (including links to any other works you want me to link to) and free ACX subscriptions. And all winners will get the right to pitch me new articles if they want (nobody ever takes me up on this). Your due date is April 5th. Good luck! If you have any questions, ask them in the comments. And remember, the form for submitting entries is here.

Feb 3, 2023 • 1h 18min
Response To Alexandros Contra Me On Ivermectin
https://astralcodexten.substack.com/p/response-to-alexandros-contra-me I. In November 2021, I posted Ivermectin: Much More Than You Wanted To Know, where I tried to wade through the controversy on potential-COVID-drug ivermectin. Most studies of ivermectin to that point had found significant positive effects, sometimes very strong effects, but a few very big and well-regarded studies were negative, and the consensus of top academics and doctors was that it didn’t work. I wanted to figure out what was going on. After looking at twenty-nine studies on a pro-ivermectin website’s list, I concluded that a few were fraudulent, many others seemed badly done, but there were still many strong studies that seemed to find that ivermectin worked. There were also many other strong studies that seemed to find that it didn’t. My usual heuristic is that when studies contradict, I trust bigger studies, more professionally done studies, and (as a tiebreaker) negative studies - so I leaned towards the studies finding no effect. Still, it was strange that so many got such impressive results.