Bayesian analysis of Slate Star Codex survey data.

[Epistemic status: I’m teaching myself Bayesian analysis out of an O’Reilly-esque programming book; I haven’t yet mustered myself to crack the intimidating Andrew Gelman tome on my shelf. I beg you, correct me if I have screwed this up.]

Scott Alexander posted his survey data results several months ago, and recently has been posting some interesting things about how different groups perceive optical illusions.

As part of my quest to finally understand the differences between Bayesian analysis and frequentist analysis, I downloaded his data and poked at it with PyMC, again modeling my analyses after those in chapter 2 of Bayesian Methods for Hackers, by Cameron Davidson-Pilon (the A/B testing example and the Challenger example.)

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CNN did not commit blackmail but did abuse “newsworthiness.”

After some discussion on Popehat yesterday, I’m convinced that blackmail is the wrong way to look at the CNN thing. Blackmail has two elements1, a threat and a demand:

  1. It’s okay to tell my wife about the affair.
  2. It’s okay to not tell my wife about the affair.
  3. It’s okay to ask me for $50,000.
  4. But it’s not okay to condition the choice between (1) and (2) on (3); that’s blackmail.

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There is no “populist surge.”

Larry Bartels on the non-existent populist surge.

I mentioned something like this in my review of Dividing Lines,

…it’s a ironic time for an anti-immigrant populism to take power; immigration levels from Mexico have fallen dramatically over the past decade or so, to the point where net migration is now negative. And at the same time, the American public has recently become friendlier than ever before to the idea of immigration (okay, perhaps “friendlier” means “less hostile”; people want less immigration now outnumber people who want more immigration by only two-to-one.)

As I think about it now, I realize this reinforces (what I see as) the book’s central claim – that American immigration policy is driven by partisan coalitions, not public opinion.  And so the future viability of Trump-like candidates will depend, not chiefly on public opinion, but on how well Republican elites can control the nomination process.


I just added a blogroll.  In the long run I would prefer that it contain more links to independent blogs, but for now it’s an honest reflection of what I read, which is heavy on columnists for major publications.

On Eating Moderately

Disclaimer: Nothing I write here is a criticism, in the pejorative sense, of Guyenet’s advice; he reports scientific findings faithfully and we can ask no more than that.  Instead, I want to explore why some people find his advice discouraging.  Also, note that Guyenet’s advice involves more than just reducing food reward – he says you can also lose weight by eating a high-protein diet, exercising more, sleeping better, and reducing stress.

Scott Alexander suggested that the implications of The Hungry Brain are “neo-Puritan”, and I more or less repeated that claim in my review of the book.  However, it could be argued that every diet plan is puritanical – after all, every diet plan, from the quackiest to the most scientifically sound, offers the same basic promise: Restrict in some way your consumption of delicious foods, and you will lose weight.  Is Guyenet’s advice any different?

I think it is.

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Other people study Obama/Trump voters reports on several papers using data from the Voter Study Group, focusing on Obama/Trump voters – the same voters I analyzed in my series of posts.  (I’m also linking to the article because I take petty joy in being responsible for a correction in a published piece – the one from June 22nd was my catch.) They reach basically the same conclusions as I did: That Obama/Trump voters were ethnocentric but economically populist.

Jamelle Bouie, the author of the piece, raises a possibility that I did not mention in my posts: That Trump’s economically moderate campaign messages may have mattered almost as much as his ethnocentric messages on immigration and crime.  Given Trump’s governing record, he will be unable to re-run convincingly as an economic moderate in 2020, which may mean that the Democrats can win back some of these voters without changing their messaging in any way.

(It’s also possible that if Black Lives Matter protests become fewer or less visible by 2020, the racially-loaded politics of crime may seem less salient to these voters.)

Book Review: The Hungry Brain

It was joked, of Soviet factories, that if performance were measured by the number of nails produced, they would produce a multitude of nails too small to use; if performance were measured in tonnage, they would produce only one, gigantic nail.


Capitalism has sort of the opposite problem with food – regardless of what you say you want, capitalism will give you what you crave, for a low, low price.  You say you want less fat, capitalism will produce food in which the fat has been replaced by sugar.   You say you want less sugar, capitalism will replace sugar with cane syrup.  You say you want simple foods with only a few ingredients, capitalism will ensure that three of those ingredients are sugar, fat, and salt.  Natural foods? Capitalism will find a way to source commercial additives naturally.  Local foods?  Capitalism will build factory farms locally.

This tendency was on my mind as I read The Hungry Brain, by Stephan Guyenet.  I learned of the book from Scott Alexander’s recent review, and Guyenet’s blog had previously been recommended to me by several very smart people.  Scott’s review is thorough, which spares me the effort of recapping every argument in the book; however, it seems to me Scott reads the book through a certain lens (asking whether weight loss is a matter of willpower, and what the role of genes is) whereas I read it through another.  For that reason, I will focus on what I think the book’s argument has to say about two questions:

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