March 23, 2024

The "Quality Control" Interview for Big Classes

Attention conservation notice: Advice on teaching, which I no longer follow myself.

I teach a lot of big classes --- the undergraduate advanced data analysis class passed 100 students many years ago, and this fall is over 230 --- which has some predictable consequences. I don't get to talk much to many of the students. They're mostly evaluated by how they do on weekly problem sets (a few of which, in some classes, I call "take-home exams"), and I don't even grade most of their homework, my teaching assistants do. While I try to craft problem sets which make sure the students practice the skills and material I want them to learn, and lead them to understand the ideas I want them to grasp, just looking at their scores doesn't give me a lot of information about how well the homework is actually working for those purposes. Even looking at a sample of what they turn in doesn't get me very far. If I talk to students, though, I can get a much better sense of what they do and do not understand fairly quickly. But there really isn't time to talk to 100 students, or 200.

About ten years ago, now, I decided to apply some of the tools of my discipline to get out of this dilemma, by means of random sampling. Every week, I would randomly select a fixed number of students for interviews. These interviews took no more than 30 minutes each, usually more like 20, and were one-on-one meetings, distinct from regular open office hours. They always opened by me asking them to explain what they did in such-and-such a problem on last week's homework, and went on from there, either through the problem set, or on to other topics as those suggested themselves.

In every class I did this in, it gave me a much better sense of what was working in the problems I was assigning and what wasn't, which topics were actually getting through to students and which were going over their heads, or where they learned to repeat examples mechanically without grasping the principle. There were some things which made the interviews themselves work better:

  • Reading each students' homework, before the meeting. (Obvious in retrospect!)
  • Handing the student a copy of what they turned in the week before. (Though, as the years went on, many brought their laptops and preferred to bring up their copy of the document there.)
  • Putting a firm promise in the syllabus that nothing students said in the interview would hurt their grade. (Too many students were very nervous about it otherwise.)
  • Putting an equally firm promise in the syllabus that not coming in to the interview, or blowing it off / being uncooperative, would get them a zero on that homework. (Obvious in retrospect.)
  • Offering snacks at the beginning of the interview.

Setting aside a fixed block of time for these interviews didn't actually help me, because students' schedules are too all-over-the-place for that to be useful. (This may differ at other schools.)

Choosing the number of students each week to interview has an obvious trade-off of instructor time vs. information. I used to adjust it so that each student could expect to be picked once per semester, but I always did sampling-with-replacement. In a 15-week semester with 100 students, that comes out to about 3.5 hours of interviews every week, which, back then, I thought well worthwhile.

I gave this up during the pandemic, because trying to do a good interview like this over Zoom is beyond my abilities. I haven't resumed it since we went back to in-person teaching, because I don't have the flexibility in my schedule in any more to make it work. But I think my teaching is worse for not doing this.

Corrupting the Young

Posted at March 23, 2024 15:10 | permanent link

The Presentation Exchange for Workshops and Classes

Attention conservation notice: Advice for running an academic workshop, which I've only followed myself a few times.

Some years ago, Henry Farrell and I ran a series of workshops about cooperative problem-solving and collective cognition where we wanted to get people with very different disciplinary backgrounds --- political theorists, computer scientists, physicists, statisticians, cognitive psychologists --- talking to each other productively. We hit upon an idea which worked much better than we had any right to hope. (Whether it's ultimately due to him, or me, or to one of us tossing it out as obviously dumb and the other saying "Actually...", neither of us can now recall.) We've both used it separately a few times in other settings, also with good results. Since we both found ourselves explaining it recently, I thought I'd describe it in a brief note.

  1. Every participant in the workshop writes a brief presentation, with enough lead time for the organizers to read them all.
    In the context of an inter-disciplinary workshop, what often works best is to describe an outstanding problem in the field.
  2. The workshop organizers semi-randomly assign each participant's presentation to someone else, with enough lead time that the assignee can study the presentation.
    Again, in the interdisciplinary context, the organizers try to make sure that there's some hope of comprehension.
    (While I called this the "presentation exchange", it needn't be a strict swap, where A gets assignd B's presentation and vice versa.)
  3. Everyone gives the presentation they were assigned, followed by their own comments on what they found interesting / cool / provocative and what they found incomprehensible. No one gives the presentation they wrote.
    In some contexts, I have found it helpful to institute the rule that the author don't get to speak until after the presentation is finished...

Doing this at the beginning of the workshop helps make sure that everyone has some comprehension of what everyone else is talking about, or at least that mis-apprehensions or failures to communicate are laid bare. It can help break up the inevitable disciplinary/personal cliques. It can, and has, spark actual collaborations across disciplines. And, finally, many people report that knowing their presentation is going to be given by someone else forces them to write with unusual clarity and awareness of their own expert blind-spots.

As I said, Henry and I hit on this for interdisciplinary workshops, but I've also used it for disciplinary workshops --- because every discipline is a fractal (or lattice) of sub-sub-...-sub-disciplinary specialization. I've also used it for student project classes, at both the undergrad and graduate level. That requires more hand-holding and/or pastoral care on the part of the teacher than a research workshop, and I've never tried to make it the way I start a class.

Learned Folly; The Collective Use and Evolution of Concepts; Corrupting the Young

Posted at March 23, 2024 15:05 | permanent link

July 31, 2023

Books to Read While the Algae Grow in Your Fur, July 2023

Attention conservation notice: I have no taste, and no qualifications to opine on the sociology and industrial organization of intellectuals, political philosophy, or American history. Also, most of my reading this month was done at odd hours and/or while bottle-feeding a baby, so I'm less reliable and more cranky than usual.

Allison Brennan, The Lost Girls, Make Them Pay, Breaking Point, Too Far Gone
Mind candy series mystery. As with many long-running series, the soap-operatic elements keep piling up, and I honestly enjoyed those less than seeing Lucy tackle the murder-or-kidnapping-of-the-week, but still fun. (Previously.) §
Daniel Drezner, The Ideas Industry: How Pessimists, Partisans, and Plutocrats are Transforming the Marketplace of Ideas
Popular social science. Drezner's main argument is as follows. He begins by distinguishing between "public intellectuals", who are critical and multi-sided, and "thought leaders", who have One Big Idea (if not One Weird Trick), which they push relentlessly. (I don't think the phrase "policy entrepreneur" appears in the book; the old-fashioned but apt term "projector" definitely doesn't.) Recent changes in the societies of the rich democracies have increased the sway of thought leaders, and reduced that of public intellectuals.
One of these is rising economic inequality ("plutocrats"): rich people are constitutionally more inclined to pay for advocacy, especially flattering or self-serving advocacy, than for critique. Here Drezner advances, without much fuss, some sensible-sounding notions about the relations between material interests and ideology. (I actually wish he'd elaborate a theory of ideology on this basis, but that would call for a different sort of book.)
A second change is the rise of partisanship. This makes it easier to ignore criticisms coming from the other side. (You will, after all, often be right in thinking that those criticisms are made ignorantly, in bad faith, or merely to posture before the critic's own side.) This is, of course, bad for reason and democracy.
The third change is the decline in trust in established institutions ("pessimism"). These have not been replaced by alternative gate-keeping institutions, but rather by more of a free-for-all scrum for attention. (Again: "Actually, 'Dr. Internet' is the name of the monsters' creator.") This exacerbates already-existing tendencies in intellectual life to highly-skewed, winner-take-a-hell-of-a-lot outcomes. His descriptions of the temptations to chase those rewards is vivid.
Drezner does little to address why plutocrats, partisans, and the plain people of the Internet should have such an appetite for intellectual fare. It's probably impossible for social animals of our sort to conduct our common lives without justifications and rationalizations (cf. Mercier and Sperber). That those rationales should be intellectual, that they should take the form of culturally-transmitted abstractions, general ideas, appeals to impersonal principle, appeals to evidence, attempts at logical argument, etc., is another matter and evidently far more contingent. Here I personally would gesture at the very high levels of education attained in all the countries Drezner is concerned with, and/or generations of the Flynn effect.
Drezner is careful to explain that the changes and prospects are not all grim. (There are real benefits to less gatekeeping, even for public intellectuals in Drezner's sense.) He's also careful to note that in many ways the social life of the mind has always been bad. (This is cold comfort, but at least avoids catastrophizing.) But he leaves me convinced that he's right about specific ways in which that social life has recently become dysfunctional than it was, with little prospect of improvement in the foreseeable future. §
Disclaimer: Drezner is a co-author of a co-author, and a fellow relic of the The Second Age of the Web early '00s blogging. But I don't think we've ever met, and I feel no obligations to read or to praise his books. (Especially not years after they come out...)
Cormac McCarthy, Blood Meridian, or, The Evening Redness in the West
Re-read in memoriam. This is a strange but effective fusion of truly ugly action and truly beautiful language. Revisiting after some decades, I can see how it's influenced a lot of other, later books I've read, some for the better, some very much not. (If it weren't for the dates, I'd think Stephen King's The Gunslinger was in the former set.)
Two thoughts: 1. As usual, it's a mistake to identify the opinions of characters --- even ones who are given a lot of room to opine --- with the opinions of the author. In particular, I see a lot of people quoting the judge's speeches as though they were Cormac's views, but the action of the novel makes it clear that the judge is a cunning, deceitful, possibly-inhuman villain! He is not to be trusted! (Reading is hard.) 2. Something about the narration's frequent recourse to the ancient, the primeval, to mysterious forces under the earth, etc., makes me wonder about what Cormac thought of Lovecraft. §
Disclaimer: I knew Cormac through SFI; not well, but well enough to call him Cormac.
Tommie Shelby, The Idea of Prison Abolition
This is a thorough and sympathetic, but ultimately very negative, investigation of case for abolition of prisons, from a view point that tries to meld analytical Marxism with what's come to be called the "black radical tradition" [1]. Much of the argument here proceeds by way of exposition and critique of the prison-abolitionist writings of Angela Davis [2].
Many self-proclaimed prison abolitionists seem to merely be expressing outrage at way we treat crime through hyperbole. But some of them mean it. (Some of them, I suspect, have been swayed by their own hyperbole.) In any event it's a morally serious issue, which deserves to be examined with some care, whatever one might think of some of its advocates. This Shelby does.
Shelby outright dismisses the idea that society might have a legitimate interest in meeting out retribution for crimes [3], but accepts interests in deterrence [4], in rehabilitation, and (I think) in incapacitation. He further explains that consequences for anti-social behavior will only deter if they are, in fact, unpleasant. This does not mean that those consequences need to be horrors, but unless people would rather not experience them, they simply will not work. Even if one wishes to emphasize gentler means that might better serve the aims of rehabilitation and (perhaps) incapacitation, those will need to be back-stopped by some kind of deterrence of those who are neither rehabilitated nor incapacitated.
Shelby tries his best to be fair to Davis's claims that the legitimate social functions of prisons can be better served without imprisonment, but ends up having to admit that there just isn't very much substance to those claims. I honestly doubted whether he was really being fair to Davis here, so at this point read her Are Prisons Obsolete?, and concluded that Shelby was being, in fact, far too generous.
To sum up, Shelby pretty convincingly demolishes the arguments for prison abolition, i.e., for thinking that prisons have no place in just societies. He is very careful to say that none of his arguments imply that current American prisons, or our criminal justice system more generally, are acceptable. §
Disclaimer: I met Shelby years ago at a workshop, where I was impressed by his presentation, and he was generous with his time in offering suggestions on work-then-in-progress. This contributed to my picking up his book.
[1]: Shelby elaborates on his conception of his own "Afro-Analytical Marxism" in this 2021 essay. Like most analytical Marxists, he seems more interested in fairly orthodox historical materialism and political economy --- the sort of topics someone shaped by the Second International, like Kautsky or Trotsky or Luxemburg, would've recognized --- than in the Frankfurt School. (Davis, of course, as Marcuse's student, owes more to Frankfurt.) Thus I think can continuing to view Joseph Heath as the world's leading, because only, rational-choice critical theorist. ^
[2]: Certain episodes in Davis's career go (tactfully?) unmentioned. ^
[3]: The dismissal is forthright, but perhaps a bit hasty. Those who are wronged by others, or their family and friends, will tend to seek retribution from those who have wronged them. In fact they will tend to seek disproportionate and intemperate retribution. Such excessive retribution is both unjust itself, and apt to set of a vicious cycle of feud and revenge. To prevent this, punishment of wrong-doers by the state must include, and be seen to include, reasonable and proportionate retribution. --- To be clear, I'm not saying this is unanswerable, just that I wish Shelby hadn't dismissed retribution so swiftly. ^
[4]: There is a disconcerting possibility about deterrence which Shelby doesn't discuss, but which his arguments do not, so far as I can see, foreclose. This is that punishing people for crimes they didn't commit would have much the same deterrent effect as punishing the guilty, so long as most people thought that they were guilty. Someone has to suffer in order to fulfill the legitimate public function of deterring wrong-doing [5], but it's trickier than I'd like to say why, ethically, it should be criminals who do the suffering. (Of course, the task becomes easier if one believes in retribution.) ^
[5]: Conversely, I could easily make a case for the authorities only convincingly pretending to punish anyone. But such a deception would be very fragile, with bad consequences when it unraveled; perhaps that's enough to rule it out. ^
Bryan Burrough, Days of Rage: America's Radical Underground, the FBI, and the Forgotten Age of Revolutionary Violence
A journalistic, but very thorough, history of violent left-wing radicals from the late 1960s through the early 1980s. (Right-wing violence during the same period is outside Burrough's scope, but it would make an interesting set of comparison cases.) Many of the figures he discusses --- including Davis! --- also show up in Shelby's book, albeit presented in rather different lights. §
Adolph Reed, Jr., The South: Jim Crow and Its Afterlives
If you like Reed's essays at (and I usually do), you will enjoy this, and if not, not. The marketing material from the publisher makes it seem vastly more ambitious than it really is, but Reed's introductory remarks make the scope clear. §
Simon Spurrier and Matías Bergara, Coda vols. 1, 2, 3
Comic book mind candy fantasy. Superficially, this is a cynical, post-apocalyptic subversion of the Matter of Middle Earth. In fact, the hard-bitten surface merely conceals a core which actually believes in epic fantasy, both in the content and in the classical form (a trilogy ending in a eucatastrophe). §

Books to Read While the Algae Grow in Your Fur; The Beloved Republic; The Progressive Forces; Philosophy; Commit a Social Science; The Collective Use and Evolution of Concepts; Pleasures of Detection, Portraits of Crime; Scientifiction and Fantastica; Tales of Our Ancestors; The Commonwealth of Letters

Posted at July 31, 2023 23:59 | permanent link

June 22, 2023

On Shoggothim

Attention conservation notice: Self-promotion of a pay-walled piece which combines a trendy topic with what even I admit is a long-held semi-crank notion.

Henry Farrell and I have an essay in The Economist, riffing off the meme that every large language model is really a shoggoth. Our point is that this is right, because an LLM is a way of taking the vast incohate chaos of written-human-language-as-recorded-on-the-Web and simplifying and abstracting it in potentially useful ways. They are, as Alison Gopnik says, cultural technologies, more analogous to library catalogs than to individual minds. This makes LLMs recent and still-minor members of a larger and older family of monsters which similarly simplify, abstract, and repurpose human minds: the market system, the corporation, the state, even the democratic state. Those are distributed information-processing systems which don't just ingest the products of human intelligence, but actually run on human beings --- a theme I have been sounding for while now.

The piece is paywalled, but Henry has a Twitter thread that provides a good summary, and Brad DeLong has excerpts, along with thoughtful commentary. (I agree with Henry's response to said comments.) Update, 7 July: Henry links to the longer, older version we cut down for The Economist.

Some things we didn't include:

  • Thanks to the editorial staff at The Economist, both for the opportunity and for their very professional work.
  • Thanks to Ted Chiang (!) for helpful comments on a draft.
  • Any discussion of LLMs as artifacts, in the sense of Herbert Simon's Sciences of the Artificial. (I for one learned this way of thinking of markets and hierarchies as information-processing systems from Simon...) Update, 17 August: I endorse Maxim Raginsky's treatment of this topic.
  • Any discussion of Dan Sperber's account of culture as "the precipitate of cognition and communication in a human population", the role in that process of chains of alternately private-mental and public-physical representations, and LLMs as public-representation-producing artifacts
  • Any discussion of Arthur Stinchcombe's work on the positive role of abstraction and formalities in institutions
  • "More is different": These things emerge from the massed results of human social interaction and individual intelligence, and therefore are very different from human minds. In particular, they tend to have their own intrinsic dynamics, which are usually not things anyone intends, and often things no-one wants. (Someday I will write that essay about blackouts and alienation.) That doesn't mean they can't be controlled; it means control is hard, and usually itself impersonal.
  • An adequate discussion of monster-taming and its limits, which would necessarily include extended praise of social democracy (though see DeLong's post)
  • Any mention of the the primal scene of AI.
  • Henry's reflections on modern neo-Lovecraftian fiction, which I hope he will publish elsewhere. Update, 7 July: see.

Update, 23 June: Small wording tweaks and additions. More important: insightful and generous commentary from Daniel "\( D^2 \)" Davies. (It's virtually a blogosphere reunion.) Incorporated (sorry) by reference: Beniger, The Control Revolution; Yates, Control through Communication; Ashby, "Design for an Intelligence Amplifier".

(I know I learned that the correct plural of "shoggoth" is "shoggothim" from reading Ruthanna Emrys, but I cannot now locate the passage --- it may just be in her Lovecraft Reread series with Anne Pillsworth.) Update: and indeed it was (tracked down by Henry).

Self-Centered; The Collective Use and Evolution of Concepts; Cthulhiana; The Great Transformation

Posted at June 22, 2023 12:45 | permanent link

April 30, 2023

Books to Read While the Algae Grow in Your Fur, April 2023

Attention conservation notice: I have no taste, and no qualifications to opine on the biographies of 20th century tyrants, or the impact of the Internet on collective creativity. Also, most of my reading this month was done at odd hours and/or while bottle-feeding a baby, so I'm less reliable and more cranky than usual.

Wislawa Szymborska, Poems New and Collected, 1957--1997
Donald Hall, Selected Poems
I observe National Poetry Month by reading poets I really ought to have read already. (I'd seen Szymborska's "A Word on Statistics", of course, IIRC from Thomas Lumley.)
Leigh Bardugo, Hell Bent
Mind candy fantasy / campus novel, in which Yale is literally a gateway to Hell. It's a sequel to Ninth House, and it'll be much more enjoyable if you read that first, but there's enough cluing-in for the new reader that it's probably not necessary. Ends in media res. §
Andrea Fort et al., Songs for the Dead: Afterlife
Mind candy fantasy, comic book flavor. A satisfying conclusion to the story. §
Robert Louis Stevenson, The Strange Case of Dr. Jekyll and Mr. Hyde
Yes, I knew the story. No, I had never actually read it before. Yes, it's really good. §
Stephen Kotkin, Stalin, volumes I, Paradoxes of Power, 1878--1928 and II, Waiting for Hitler, 1929--1941
Writing an adequately-contextual biography of Stalin means, for Kotkin, pretty much writing a history of the world, as well as detailing the ups and downs of Ioseb Barionis Jughashvili. I think this is right, and am entranced at how well Kotkin tacks back and forth between different scales. One of the themes those constant changes of scale let Kotkin explore is the tension between large, structural forces or trends --- particularly the imperative pressure on any state that wanted to retain independence to industrialize (cf.) --- and fine-grained and contingent yet consequential facts of friendship and rivalry, of personality, even of sheer accident. (These are very non-Marxist books, which could only have been written by someone who had seriously wrestled with Marxist thought.) I very eagerly await the next volume (or volumes?). §
Clay Shirky, Cognitive Surplus: Creativity and Generosity in a Connected Age
Reading a 2010 book about the promise of the Internet for cooperation, especially for intellectual collaboration, in 2023 is, well, rather melancholy. Instead of carpooling, we have giant illegal taxi companies; instead of safe couch-surfing, we have giant illegal hotel chains; instead of sharing information about political violence, we have organizing political violence; and instead of sharing information about rare medical conditions, we have created multiple new forms of contagious hysteria.
One conclusion I draw from this is that Shirky was fundamentally right about how the Internet would unleash new forms of collective creativity, but far, far too optimistic about the value of that creativity. ("After all, to any rational mind, the greater part of the history of ideas is a history of freaks.")
The other conclusion --- one I've been tending to for a while --- is that as a teenager, I got caught up in a Utopian milieu, which somehow thought that integrating the Internet, and especially the Web, into civilized life would make things better. I spent my adult life in this environment, it was very good to me (and I daresay to Shirky). But, thirty years later... Well, I often find myself thinking on a passage from Fear and Loathing in Las Vegas, reflecting on another such hangover:
There was a fantastic universal sense that whatever we were doing was right, that we were winning...
And that, I think, was the handle --- that sense of inevitable victory over the forces of Old and Evil. Not in any mean or military sense; we didn't need that. Our energy would simply prevail. There was no point in fighting --- on our side or theirs. We had all the momentum; we were riding the crest of a high and beautiful wave...
So now, less than five years later, you can go up on a steep hill in Las Vegas and look West, and with the right kind of eyes you can almost see the high-water mark --- that place where the wave finally broke and rolled back.
Shirky was offering a view from the crest of the wave. This one didn't exactly break and roll back; it just left the same old rubbish as before in its wake, only sodden and salt-rimed. This is, perhaps, the best a utopia can hope to achieve. §
Disclaimer: I'd forgotten, until I was almost ready to post this, that back in the Second Age of the Web 2003--2004 Shirky and I were both parties to a discussion involving the exact shape of the degree distribution for weblogs. That dispute is irrelevant to the subject of this book, and has no bearing on my views of it. (For the record: he was wrong about the degree distribution.)

Books to Read While the Algae Grow in Your Fur; Writing for Antiquity; The Progressive Forces; Linkage; The Collective Use and Evolution of Concepts; Actually, "Dr. Internet" Is the Name of the Monsters' Creator; Scientifiction and Fantastica; The Commonwealth of Letters

Posted at April 30, 2023 23:59 | permanent link

March 31, 2023

Books to Read While the Algae Grow in Your Fur, March 2023

Attention conservation notice: I have no taste, and no qualifications to opine on African-American political psychology, opinion-survey research, medieval Islamic Indology, or the history of the scientific revolution. Also, most of my reading this month was done while recovering from foot surgery and/or while bottle-feeding a baby, so I'm much less reliable and more cranky than usual.

Kel Symons et al., I Love Trouble
Cecil Castellucci and Marley Zarcone, Shade, the Changing Girl
Cullen Bunn et al., Harrow County, vols. 2, 3, 4, 5, 6, 7, 8
Philippe Thirault et al., Miss: Better Living Through Crime
Kurt Busiek et al., The Autumnlands, vols. 1 and 2
Ryan North et al., The Midas Flesh, vol. 2
Comic-book mind candy, assorted. Autumnlands reminds me a little of Zelazny from the 1960s or 1970s. --- Previously for Midas Flesh; previously for Harrow County.
Paul M. Sniderman and Thomas Piazza, Black Pride and Black Prejudice [JSTOR]
The central question here is whether, among African Americans in the greater Chicago area circa 2000, higher levels of racial pride lead to higher levels of prejudice against those not in the race, especially (but not exclusively) against Jews. The authors addressed this through opinion surveys, including some ingenious survey experiments *.
On substantive grounds I have little to say here. What troubles me about this though is that the authors (and their critics) seems content to take few-level ordinal data and run it through linear regression after linear regression, endlessly permuting which variable goes on the left hand side and which ones are on the right. The ideas about validating measurements are hopeless, along the lines of the Zeller and Carmines book which so disappointed me (unsurprisingly, since Sniderman and Carmines collaborated). They are also prone to the fallacy of confusing "this regression coefficient is not statistically significant" with "this relationship is unimportant" **, and they never once look at their residuals to check their a regression specification. To be clear, I have no doubt that the survey was done as well as humanly possible; it's the analysis of the results which drives me nuts.
At some point, I confess, I wanted to make them shut down their statistical software, hand over the data set, and run the whole thing through pcalg myself, using the chi-squared test for conditional independence that works for categorical variables. (This would assume all the systematically-important variables are measured, but then, so do their regressions.) I would then hand them back the inferred graphical causal model, and let them use it to address their substantive questions. (This is of course a fantasy, because pcalg didn't exist --- but not such a fantasy, because TETRAD was a thing in 2002.) The upshot of my fantasy would be a comprehensible, reliably-constructed guess at how all their different variables inter-relate, allowing one to draw real inferences. The way they actually proceeded instead gave them an uninterpretable mush --- or, rather, a mush which demands interpretation rather than supporting calculation. In all this, of course, they are no worse than most quantitative social science. §
*: Reassuringly, including indicator variables for their experimental treatments makes no differences to the coefficients of other variables in their regressions. They do not appear to appreciate that this has to be true if the treatments were successfully randomized (so the treatment indicator is linearly unpredictable from the covariates). This would not be true if the treatment interacted with the covariates, but they never consider interactions anyway. ^
**: To repeat a teaching example: "Imagine hearing what sounds like the noise of an animal in the next room. If the room is small, brightly lit, free of obstructions, and you make a thorough search of it with unimpaired vision and concentration, not finding an animal in it is, in fact, good evidence that there was no animal there to be found. If on the other hand the room is dark, large, full of hiding places, and you make a hurried search while distracted, without your contact lenses and after a few too many drinks, you could easily have missed all sorts of things, and your negative report has little weight as evidence. (In this parable, the difference between a large [coefficient] and a small [coefficient] is the difference between looking for a Siberian tiger and looking for a little black cat.)" ^
Abu Rayhan Muhammad ibn Ahmad al-Biruni, Alberuni's India: An Account of the Religion, Philosophy, Literature, Geography, Chronology, Astronomy, Customs, Laws and Astrology of India about A.D. 1030 (trans. Edward C. Sachau, 1888; online in two volumes)
Biruni went to India in the wake of the armies of his patron/captor, Sultan Mahmud of Ghazni, and stayed for a dozen years or so, learning languages, studying the country, and assimilating Hindu learning. This is his attempt at summarizing what he thought was most important about Indian culture for a Muslim audience. It's encyclopedic, sympathetic, admiring, sometimes exasperated, occasionally baffled. I can't find a more recent translation into English, so this one from the 19th century had to do. It's mostly readable, though there are quite a few places where the translator calls for more research and this reprint, naturally, doesn't say whether it's been followed up *. In any event, I found this fascinating. One aspect which particularly struck me is Biruni's concern with convincing the reader that educated Hindus are really monotheists, drawing explicit analogies to Christian veneration of saints, "idols", etc. I think the goal here is to get the reader to not dismiss Indian thought as mere pagan superstition. (But might he be hinting that Hindus are really a People of the Book?) §
*: Sachau does have the odd habit of rendering some of Biruni's Arabic technical and philosophical vocabulary as (English renditions of) Greek words. I found this vexing, because he never explains whether this is because an Arabic term was itself a translation of a Hellenistic original, or whether he just thinks Greek would be more familiar to a Victorian audience, or what. I realize this is me tweaking a 19th century Orientalist scholar for insufficient philological exactitude, and can't wait to find out what form karma will take. ^
David Wootton, Galileo: Watcher of the Skies
For the most part, this is a very able, even exciting, biography of Galileo, and a defense of him as a scientist and a natural philosopher from criticisms by the likes of Feyerabend. There are, however, one or two passages of truly wild psychoanalysis, so wild I can't begin to say whether Wootton means those bits seriously. So: mostly what I expected from the author of The Invention of Science. §

Books to Read While the Algae Grow in Your Fur; Scientifiction and Fantastica; Writing for Antiquity; Islam and Islamic Civilization; The Great Transformation; Commit a Social Science; Enigmas of Chance; The Beloved Republic

Posted at March 31, 2023 23:59 | permanent link

February 28, 2023

Books to Read While the Algae Grow in Your Fur, February 2023

Attention conservation notice: I have no taste, and no qualifications to opine on the economic of socialism (whether actually-existing or hypothetical), political philosophy, the social organization and intellectual development of literary criticism, or participatory democracy in social movements. Also, most of my reading this month was done at odd hours and/or while bottle-feeding a baby, so I'm less reliable and more cranky than usual.

Alec Nove, The Economics of Feasible Socialism (1983)
Alec Nove, Political Economy and Soviet Socialism (1979)
Alec Nove, Socialism, Economics and Development (1986)
Alec Nove, Efficiency Criteria for Nationalised Industries (1973)
Alec Nove and J. A. Newth, The Soviet Middle East: A Model for Development? (1967)
Nove was (as these titles might suggest) a British economist, the child of exiled Mensheviks, who made a specialty of studying the Soviet economy, and of advocating market socialism. He's best known for two works: The Economics of Feasible Socialism and An Economic History of the USSR. The former is a personal touchstone which shaped me deeply; the later is merely very good. Looking up something else, I happened to discover that a bunch of his books are now available through our library electronically, so I plunged in.
I'll start with the most important book first. The point of Feasible Socialism is to advocate for, and sketch, a socialist economy "which might be achieved within the lifetime of a child already conceived", i.e., not in some distant post-scarcity future. The first chapter explains why Marxism offers absolutely no useful ideas about how to actually run a socialist economy. (Here Nove summarizes Soviet debates on this matter in the early 1920s --- debates which have been little known since, and so often, in effect, re-run from scratch.) The second chapter looks at the entirely-negative lessons to be drawn from the Soviet experience, and the third at the mostly-negative lessons to be drawn from Cold War-era Hungary, Yugoslavia, Poland and China. The last two chapters lay out Nove's attractive vision of a market socialism, with lots of public provision of many goods, and workplace democracy where sensible and feasible. (He is sound on seeing that there is a tension between democratic control of an enterprise by its workers, and democratic control of that enterprise by the people-as-a-whole.)
On re-reading, I am relieved, chagrined, and exasperated. Relieved, because I still think this book holds up, and has not been visited by the Suck Fairy. Chagrined, because I've written a lot about socialism and planning over the years, some of it well-received, and on examination I have just been channeling a book I first read as a teenager. Exasperated, because we keep having the same conversations about the same bad ideas, without actually being able to retain and build on the better ones, like Nove's. (I have been making this complaint on this blog for nineteen years now.)
Since I have a weird completist tendency, I then proceeded to read the other four books here, since I hadn't read them before, and they were available.
The first two are collections of academic papers and essays; many of them are effectively studies for Feasible Socialism, not always in very obvious ways: Nove account of more-or-less self-inflicted economic crises facing Allende's government in Chile (observed as visiting faculty in Santiago) clearly informs his discussion of the transition to socialism. I also found very interesting his series of papers on the economic thought of the Bolsheviks (from before the revolution through the 1930s), and later Soviet economics of the 1960s and 1970s (i.e., Kantorovich and co. versus traditionalists).
Efficiency Criteria is a plea to think about why one would want a nationalized industry in the first place, as opposed to just regulating and taxing private firms.
The Soviet Middle East looks at economic development efforts in the Caucasus and Central Asia. The emphasis is on flows of money, machinery and trained personnel from the center to these regions. The environmental costs imposed go largely unremarked. That this was a project of imperial domination is on the other hand made very clear.
To sum up: go track down a copy of Feasible Socialism, if that side of what I write interests you at all. The rest of these are now of just-historical interest, though I'm glad I read them. §
Joseph Heath, Cooperation and Social Justice
This is an essay collection, loosely united by the theme that a (functional) society is an on-going system of cooperation, which has implications for what anything we might want to call "social justice" would look like, and how it might be achieved. (Indeed, Heath would say that principles of social justice are principles that help systems of cooperation work better. [Cf.]) This supposed unifying theme is most evident in chapters 1 and 5.
Chapter 1, "On the Scalability of Cooperative Structures", is mostly a response to G. A. Cohen's Why Not Socialism?, patiently pointing out that modes of cooperation which work in a small group of friends on a temporary camping trip do not, in fact, scale up to thousands or millions of people over lifetimes. The logical weakness here is that Heath never really explains why different modes of cooperation have the scales they do.
Chapter 5 is about reasonable accommodation for immigrants: they come to new countries because they want to join that country's system-of-cooperation, so it's reasonable to mostly expect them to conform to its ways, but reasonable accommodations for them are ones which don't, in fact, impair the efficacy of the system. Turned around, this provides Heath with an argument for border control, i.e., limiting who gets to participate in the system of cooperation, in order to keep it going. I'm not sure why this latter argument doesn't allow every city's current residents to restrict who can move there, or indeed any neighborhood. Those are fragmentary systems of cooperation, inter-dependent on larger ones, but so is any national economy.
Chapter 2 argues that the fact that corporations are only supposed to pursue profit doesn't lead them to anti-social behavior; the problem isn't profit, but inadequate regulation, and poor professional ethics. (He knows better than to suppose courses on ethics lead to better behavior.) I sympathize, but don't think he gives enough consideration to (people working for) corporations expending effort to shape regulations in their self-interest.
Chapter 3 is about the importance of status to our social lives, and the dilemmas this creates for egalitarians, since status simply cannot be equalized. Complex societies will have multiple status hierarchies (I once knew someone highly esteemed among his fellow collectors of rare fruit-company banana labels), but it strains credulity to imagine a situation where everyone is at the top of a status hierarchy they find compelling.
Chapter 4 defends stigmatizing bad behaviors, on the grounds that social stigma is actually an important resource people can draw on when attempting self-control. (This idea is briefly touched on, as I recall, in Heath's Enlightenment 2.0.) The question of which behaviors should be stigmatized is left open.
Chapter 6, finally, is about the "dilemmas of US race relations", and our attempts to "achieve Singaporean outcomes using Canadian methods" (p. 299). This is thought-provoking, not least for trying to put our difficulties into comparative perspective. (This chapter is an expanded, more scholarly version of a 2021 essay in a rather odd-seeming little magazine.) On the basis of these arguments, Heath ought to endorse a sort of counterfacctual black nationalism: it'd be a good idea, if only most black people were concentrated in one part of the US where they were numerically predominant, like the Francophones in Quebec.
As my remarks make clear, I didn't come away completely satisfied with Heath's answers or arguments in every case, but I always enjoyed the reading, and found a lot more to chew over than I have time to itemize. §
John Guillory, Professing Criticism: Essays on the Organization of Literary Study
This is a wonderfully rich book, but I will just point to Merve Emre's exposition in lieu of writing my own. It makes me want to read Guillory's Cultural Capital from the 1990s. Thanks to Scott Newstok for recommending this to me. §
Francesca Polletta, Freedom Is an Endless Meeting: Democracy in American Social Movements (2002)
The usual knock on participatory democracy is that it doesn't scale to large groups, and becomes increasingly ineffective as the group gets larger. (I have scribbled out thoughts along these lines myself.) Polletta, who sympathizes very obviously and strongly with participatory democracy, especially in its more left-wing * forms, explicitly tries to counter this critique by looking, primarily, at three mid-20th-century movements: pacifists in the 1950s, the SNCC, and SDS. (She's good on the historical inter-connections between her three movements.)
Polletta has extremely astute things to say about the way participants in these movements imagined their relationships to each other, and used those conceptions to help make participation work ** . She makes it absolutely clear that participatory democracy does have heuristic and strategic value. Even more, when it's working, it has moral and morale value; her striking title comes from an SDS members's recollection of what participation meant to her.
Despite all this, Polletta completely fails to undermine the it-doesn't-scale critique. In fact, when both SNCC and SDS did get large, they famously flamed out into utterly dysfunctional wrecks, and Polletta gives honest and insightful accounts of the beginnings of the disintegration in both cases. (She doesn't follow SDS all the way into the LaRouchies and Weather Underground, but she doesn't need to.) The 1950s pacifists, of course, never grew enough to have such problems.
The end of the book covers some contemporary-at-time-of-writing movements: a surviving branch of the Industrial Areas Foundation in Texas, and anarchists around David Graeber (who features as a native informant) who would go on to be key to Occupy. By Polletta's own account, that branch of the IAF seems like a perfectly ordinary class/ethnic political formation, dominated by the group's clergy --- doing good work for its members, but not really a direct or participatory democracy, whatever motions it might go through. As for what became Occupy, again, its career hardly argues for the scalability of participatory democracy.
To sum up, Polletta makes a strong case for the virtues and powers of participatory democracy in small groups bound by strong ties of solidarity. (I am tempted to say: groups which have 'asabiyya.) She also has interesting observations on the forms those ties can take. But beyond the small group, she is, if anything, underlining that the Iron Law of Oligarchy rules ok. §
*: Right-wing political movements of the same vintage (e.g., Young Americans for Freedom) go undiscussed. Maybe none of them aspired to the same sort of internal democracy as SNCC or SDS --- I honestly don't know enough about them to say --- but if any did, they'd make extremely informative contrast cases. ^
**: She's returned to this theme in later work, which I am eager to read. --- If I were smarter, I would try to connect this to John Levi Martin's mysterious-to-me claims about the need for social structures to be comprehensible to their members. ^

Books to Read While the Algae Grow in Your Fur; The Progressive Forces; The Beloved Republic; Commit a Social Science; The Commonwealth of Letters; Philosophy; Afghanistan and Central Asia

Posted at February 28, 2023 23:59 | permanent link

December 31, 2022

Books to Read While the Algae Grow in Your Fur, December 2022

Attention conservation notice: I have no taste, and no qualifications to opine on anti-discrimination law, early 20th century shock art movements, early 20th century science fiction, or the Renaissance reception of classical mythology. Also, most of my reading this month was done at odd hours and/or while bottle-feeding a baby, so I'm less reliable and more cranky than usual.

Marie Mercat-Bruns, Discrimination at Work: Comparing European, French, and American Law (trans. Elaine Holt)
A French legal academic interviewing distinguished American legal academics about anti-discrimination law and related topics, with her commentary. (The interviews close off around 2011, so Ricci vs. DeStefano is a big subject, and the idea of a Supreme Court case instituting gay marriage nationally is definitely beyond everyone's horizon...) In between the interviews, Mercat-Bruns provides her own analysis, including a lot of discussion of French and EU legislation, regulations and case law. Her accuracy on those topics is (obviously?) not something I can evaluate, but I found it notable that she's usually asking why European law can't be more like American law. (Thus our soft-power conquest of the Old World continues.)
I read this for the inequality class, because I was unhappy repeating "I know nothing about anti-discrimination policy in other countries, sorry" in response to very reasonable questions from students. I now feel entitled to reply "I know hardly anything about how anti-discrimination law works in other countries, but...", which is progress. §
Caroline Tisdall and Angelo Bozzolla, Futurism (1977)
This is older, but it's still a really good book about the Italian Futurists. Indeed I can't think of a better one for a general audience with some background knowledge of modern art. The chapters on Futurist painting and sculpture, on music and performance, on women, and on politics are especially good.
I fell in love with Futurist painting as an undergrad, so like a freak I've read far too much about them; this book is surviving the on-going purge of my library. §
Olaf Stapledon, Star Maker (1937)
I read Last and First Men as a boy, and it warpped my mind forever, but I never attempted any other Stapledon (aside from being left cold by A Last Man in London, both as a child and as a grown-up). This was a mistake I am glad I finally fixed.
Star Maker is a very conscious attempt at creating a truly cosmic modern myth, so the whole two-billion-year saga of humanities in Last and First Men is a passing incident mentioned in a handful of paragraphs. Rather this attempts to embrace the whole life of our universe, and of the other universes which are all the work of the titular Star Maker.
A few stray notes (avoiding spoilers):
  • Some philosophical influences are very obvious: Hegel, Spinoza, Leibniz's Monadology. The Hegelianism is pervasive throughout; it leads me to wonder what a Deweyan equivalent work of science-fictional myth would be like. The Spinoza who comes through here is that of the Ethics, in particular (but not just) the "intellectual love of God", the life of the stars (and the way the order and connection of their material bodies is the order and connection of their mental lives, seen under a different aspect), and some of the presentation of eternity in the climactic myth-within-a-myth. That last is also where Leibniz is felt.
  • I will be surprised if Stapledon wasn't familiar with Attar's The Conference of the Birds, in which a group of travelers of various species move through a visionary landscape which is also a series of spiritual developments in search of a transcendent being, only to have revealed to them that they collectively are that being. (The true Simurgh is the friends they made along the way, as it were.) Just so here, with the growth of the collective group of seekers. Indeed I'd not be surprised if Attar's seven valleys map, in order, on to the stages of Stapledon's future history. (But see Allen below...)
Reading this now, with half a lifetime of consuming mind candy behind me, I can see just how much it shaped subsequent science fiction, even when that has contented itself with less ambitious and visionary, more all-too-human, projects. There are places where Star Maker is dated (the sequence of stellar evolution, the origin of planets, etc.), but it's still a magnificent venture, and I recommend it highly. §
Don Cameron Allen, Mysteriously Meant: The Rediscovery of Pagan Symbolism and Allegorical Interpretation in the Renaissance (1971, 2020) [Open Access]
For several centuries following the revival of classical learning, the received theory among European scholars and intellectuals was that the classical myths, especially as recounted in great poets like Homer, Virgil, and Ovid, were actually elaborate moral allegories and/or symbolic depictions of physical theories. These ranged from the you-can-kind-of-see-it (Circe turning Odyssesus's men, but not Odysseus himself, into swine \( \simeq \) something about reason resisting temptation to which the appetites succumb) to the excruciatingly flimsy. (I will not attempt to do justice to the elaborate encouragements to fussy virtue which were supposedly encoded in, of all books, Ovid's Metamorphoses.) Of course, the interpreters showed little agreement about exactly what a given myth was allegorizing --- except when one interpreter borrowed from his predecessors. None of the interpreters, moreover, seem to have really faced the question of why great poets would go to such pains to create elaborate allegories for rather trite morals.
Just to add to the confusion, all this went along with also seeing classical mythology as ripped off from, or a literally-demonic parody of, the Biblical Genesis story, and/or distorted memories of various historical events among the pagans (so Zeus was a king of Crete, etc.). As Allen explains, these ideas all had their roots in antiquity --- in writings of later pagans looking back at the myths (with more or less embarrassment), and in writings of the Church Fathers trying to make their own kind of sense of those stories. Medieval Christian practices of interpreting Biblical passages in multiple ways fed into the mix.
All of this was taken extremely seriously, and when Renaissance Europeans learned about classical myths, they learned them with these interpretations. Moreover, this complex of ideas helped shape how Europeans understood literary interpretation in the first place, and how they composed their own literary works. (Allen is especially good on Ariosto, Tasso and Milton.) This persisted, as Allen documents in great detail, for centuries, down through the 1700s where he calls a halt *.
From the modern perspective that began to appear in the 1700s, the idea that the classical myths were composed as elaborate moral or cosmological allegories is, of course, loony tunes. But the sheer distance between the surface story of (say) Aphrodite and Ares getting caught in adultery by Hephaestus and the ways that story was read allegorically over the centuries tells us something about how good people are at extracting meanings from anything **, about how unconstrained those meanings are by the object being interpreted, about how much, and how little, tradition and intellectual communities do to channel interpretation, and about how much of the history of ideas is a history of freaks. (Allen is more polite.) §
*: Stopping around 1750 is actually a bit disappointing to me, because the Romantic era seriously revived the idea that the ancient myths were full of hidden meanings, an idea which has persisted to this day. The Romantic mutation, however, seems to lie in implying that the meaning is personally transformative while being (strategically?) vague about just what it is. (The Renaissance mythographers, by contrast, were ploddingly explicit, and the morals were always very conventional.) It'd be very interesting to know what (say) Novalis had read in earlier mythographers. ^
**: OK, maybe not anything. I have speculated that one reason some stories last for so long is that they have a quality of suggestive ambiguity: they seem like they should mean something important, but it's not obvious what. Our surviving corpus of myths, and of renditions of myths, may have been under selection for this quality. ^

Books to Read While the Algae Grow in Your Fur; Writing for Antiquity; Scientifiction and Fantastica; Teaching: Statistics of Inequality and Discrimination; The Beloved Republic; The Commonwealth of Letters

Posted at December 31, 2022 23:59 | permanent link

November 02, 2022

Your Favorite DSGE Sucks

Attention conservation notice: 1800+ words of academic self-promotion, boosting a paper in which statisticians say mean things about some economists' favored toys. They're not even peer-reviewed mean things (yet). Contains abundant unexplained jargon, and cringe-worthy humor on the level of using a decades-old reference for a title.
Entirely seriously: Daniel is in no way responsible for this post.
Update, December 2022: Irritatingly, there are some small but real bugs, glitching all our numerical results. This is an even stronger reason for you to direct your attention elsewhere. (Details at the end.)

I am very happy that after many years, this preprint is loosed upon the world:

Daniel J. McDonald and CRS, "Empirical Macroeconomics and DSGE Modeling in Statistical Perspective", arxiv:2210.16224
Abstract: Dynamic stochastic general equilibrium (DSGE) models have been an ubiquitous, and controversial, part of macroeconomics for decades. In this paper, we approach DSGEs purely as statstical models. We do this by applying two common model validation checks to the canonical Smets and Wouters 2007 DSGE: (1) we simulate the model and see how well it can be estimated from its own simulation output, and (2) we see how well it can seem to fit nonsense data. We find that (1) even with centuries' worth of data, the model remains poorly estimated, and (2) when we swap series at random, so that (e.g.) what the model gets as the inflation rate is really hours worked, what it gets as hours worked is really investment, etc., the fit is often only slightly impaired, and in a large percentage of cases actually improves (even out of sample). Taken together, these findings cast serious doubt on the meaningfulness of parameter estimates for this DSGE, and on whether this specification represents anything structural about the economy. Constructively, our approaches can be used for model validation by anyone working with macroeconomic time series.

To expand a little: DSGE models are models of macroeconomic aggregate quantities, like levels of unemployment and production in a national economy. As economic models, they're a sort of origin story for where the data comes from. Some people find DSGE-style origin stories completely compelling, others think they reach truly mythic levels of absurdity, with very little in between. While settling that is something I will leave to the professional economists (cough obviously they're absurd myths cough), we can also view them as statistical models, specifically multivariate time series models, and ask about their properties as such.

Now, long enough ago that blogging was still a thing and Daniel was doing his dissertation on statistical learning for time series with Mark Schervish and myself, he convinced us that DSGEs were an interesting and important target for the theory we were working on. One important question within that was trying to figure out just how flexible these models really were. The standard learning-theoretic principle is that the more flexible model classes learn slower than less flexible ones. (If you are willing and able to reproduce really complicated patterns, it's hard for you to distinguish between signal and noise in limited data. There are important qualifications to this idea, but it's a good start.) We thus began by thinking about trying to get the DSGEs to fit random binary noise, because that'd tell us about their Rademacher complexity, but that seemed unlikely to go well. That led to thinking about trying to get the models to fit the original time series, but with the series randomly scrambled, a sort of permutation test of just how flexible the models were.

At some point, one of us had the idea of leaving the internal order of each time series alone, but swapping the labels on the series. If you have a merely-statistical multivariate model, like a vector autoregression, the different variables are so to speak exchangeable --- if you swap series 1 and series 2, you'll get a different coefficient matrix out, but it'll be a permutation of the original. (The parameters will be "covariant" with the permutations.) It'll fit as well as the original order of the variables. But if you have a properly scientific, structural model, each variable will have its own meaning and its own role in the model, and swapping variables around should lead to nonsense, and grossly degraded fits. (Good luck telling the Lotka-Volterra model that hares are predators and lynxes are prey.) There might be a few weird symmetries of some models which leave the fit alone (*), but for the most part, randomly swapping variables around should lead to drastically worse fits, if your models really are structural.

Daniel did some initial trials with the classic "real business cycle" DSGE of Kydland and Prescott (1982), and found, rather astonishingly, that the model fit the swapped data better a large fraction of the time. Exactly how often, and how much better, depended on the details of measuring the fit, but the general result was clear.

The reason we'd gotten in to all this was wanting to apply statistical learning theory to macroeconomic forecasting, to put bounds on how bad the forecasts would be. Inverting those bounds would tell us how much data would be needed to achieve a given level of accuracy. Our results were pretty pessimistic, suggesting that thousands of years of stationary data might be needed. But those bounds were "distribution-free", using just the capacity or flexibility of the model class, and the rate at which new points in the time series become independent of its past. This could be pessimistic about how well this very particular model class can learn to predict this very particular data source.

We therefore turned to another exercise: estimate the model on real data (or take published estimates); simulate increasingly long series from the model; and re-estimate the model on the simulation. That is, bend over backwards to be fair to the model: if it's entirely right about the data-generating process, how well can it predict? how well can it learn the parameters? how much data would it need for accurate prediction? With, again, the Kydland-Prescott model, the answer was... hundreds if not thousands of years worth of data.

Of course, even in the far-off days of 2012, the Kydland-Prescott model was obsolete, so we knew that if we wanted anyone to take this seriously, we'd need to use a more up-to-date model. Also, since this was all numerical, we didn't know if this was a general problem with DSGEs, or just (more) evidence that Prescott and data analysis were a bad combination. So we knew we should look at a more recent, and more widely-endorsed, DSGE model...

Daniel graduated; the workhorse Smets and Wouters (2007) DSGE is a more complicated creature, and needed both a lot of programming time and a lot of computing time to churn through thousands of variable swaps and tens of thousands of fits to simulations. We both got busy with other things. Grants came and (regrettably) went. But what we can tell you now, with great assurance, is that:

  1. Even if the Smets-Wouters model was completely correct about the structure of the economy, and it was given access to centuries of stationary data, it would predict very badly, and many "deep" parameters would remain very poorly estimated;
  2. Swapping the series around randomly improves the fit a lot of the time, even when the results are substantive nonsense.
The bad news is that even if this model was right, we couldn't hope to actually estimate it; the good news is that the model can't be right, because it fits better when we tell it that consumption is really wages, inflation is really consumption, and output is really inflation.

Series swapping is something we dreamed up, so I'm not surprised we couldn't find anyone doing it. But "let's try out the estimator on simulation output" is, or ought to be, an utterly standard diagnostic, and it too seems to be lacking, despite the immense controversial literature about DSGEs. (Of course, it is an immense literature --- if we've missed precedents for either, please let me know.) We have some thoughts about what might be leading to both forms of bad behavior, which I'll let you read about in the paper, but the main thing to take away, I think, is the fact that this widely-used DSGE works so badly, and the methods. Those methods are, to repeat, "simulate the model to see how well it could be estimated / how well it would predict if it was totally right about how the economy works" and "see whether the model fits better when you swap variables around so you're feeding it nonsense". If you want to say those are too simple to rise to the dignity of "methods", I won't fight you, but I will insist all the more on their importance.

It might be that we just so happened to have tried the only two DSGEs with these pathologies. (It'd be a weird coincidence, but it's possible.) We also don't look at any non-DSGE models, which might be as bad on these scores or even worse. (Maybe time series macroeconometrics is inherently doomed.) But anyone who is curious about how whether their favorite macroeconomic model meets these very basic criteria can check, ideally before they publish and rack up thousands of citations lead the community of inquirers down false trails. Doing so is conceptually simple, if perhaps labor-intensive and painstaking, but that's science.

Update, December 2022: Bugs

After posting the preprint, people helpfully found some bugs in our code. These glitch up all our numerical results. Since this is primarily a paper about our numerical results, this is obviously bad. The preprint needs to be revised after we've fixed our code and re-run everything. I am pretty confident, however, about the general shape of the numbers, because as I said we got the same kind of behavior from the Kydland-Prescott model and (importantly, in this context) off-the-shelf code. Of course, you being less confident in my confidence after this would be entirely sensible. In any event, I'll update this again when we're done with re-running the code and have updated the preprint.

*: E.g., in Hamiltonian mechanics, with generalized positions \( q_1, \ldots q_k \) and corresponding momenta \( p_1, \ldots p_k \) going into the Hamiltonian \( H \), we have \( \frac{dq_i}{dt} = \frac{\partial H}{\partial p_i} \) and \( \frac{dp_i}{dt} = -\frac{\partial H}{\partial q_i} \). A little work shows then that we can exchange the roles of \( q_i \) and \( -p_i \) with the same Hamiltonian. But you can't (in general) swap position variables for each other, or momenta for each other, or \( q_1 \) for \( -p_2 \), or even \( q_i \) for \( p_i \), etc.

The Dismal Science; Enigmas of Chance; Self-Centered

Posted at November 02, 2022 14:51 | permanent link

October 31, 2022

Books to Read While the Algae Grow in Your Fur, October 2022

Attention conservation notice: I have no taste, and no qualifications to opine on public administration, political philosophy, social epistemology, or the aims and methods of sociology. Also, most of my reading this month was done at odd hours and/or while bottle-feeding a baby, so I'm less reliable and more cranky than usual.

T. Kingfisher, What Moves the Dead
Mind candy: a re-telling of Poe's "The Fall of the House of Usher" as (is this really a spoiler?) parasite-porn horror. Amusing, and pleasingly creepy. §
Jeffrey L. Pressman and Aaron Wildavsky, Implementation: How Great Expectations in Washington Are Dashed in Oakland: Or, Why It's Amazing That Federal Programs Work at All, This Being a Saga of the Economic Development Administration as Told by Two Sympathetic Observers Who Seek to Build Morals on a Foundation of Ruined Hopes
I realize this is some sort of classic of the public policy / administration literature, so I am very late to this party, but it's really good. One way to expound this --- not Pressman and Wildavsky's, except once in passing early on --- is by an analogy with computer programming. When legislators (or dictators or executives, whatever) proclaim a policy, they state objectives and resources, and provide a sort of sketch of how they think the resources should be used to achieve the objectives. This is like getting requirements for a program and maybe some vague pseudo-code. The job of the programmer is then to implement, to actually come up with a program that runs. In the course of doing so one may discover all sorts of things about the original specification which will often call for it to be revised. If multiple programmers need to implement different parts of the specification, they will have to coordinate somehow, and may find this hard. If the program has to rely on other programs, let alone on other systems, well, good luck coordinating. §
(Link is to the 3rd edition of 1984, which is in print, though I read the 2nd of 1979, and haven't had a chance to compare the two.)
Nathan Ballingrud, Wounds: Six Stories from the Border of Hell
Horror mind candy; all six stories (the last two are really novellas) share a common mythology. Usually-reliable sources had praised Ballingrud's work, so when I ran across a cheap copy I picked this up. I understand the praise, because these are skillfully written (with an exception I will get to below), but I didn't love it, for some mostly-me reasons:
  1. While many of the props are Lovecraftian (ghouls, sanity-destroying artifacts, subterranean English cannibal cults), the underlying metaphysics is much more Christian-heretical --- "Hell" is meant very literally, and human laws and interests and emotions have great significance (if not necessarily validity) in Ballingrud's cosmos-at-large. As I have said before, I have standards for my cosmic horror, and the merely Satanic does not cut it.
  2. I think it's fair to say that basically every human emotion is depicted as a snare of Hell, love very much included. In some moods I could go along for such a ride, especially if it were presented with a lot more satirical humor, but as this went on I merely found it unpleasant.
  3. Ballingrud's endings here are generally abrupt and weak. ("Skullpocket" is a notable exception.)
So: some real merits, but I will not be seeking out more. §
Olúfémi O. Táíwò, Elite Capture: How the Powerful Took Over Identity Politics (And Everything Else)
(Note: The e in "Olúfémi" should also have a dot accent underneath, but every way I've tried to generate this makes my antiquated blogging software produce gibberish...)
I picked this up because I'd liked one of the essays it was was based on, but wished Táíwò would elaborate on the argument. (I also had hopes of using it in the inequality class.) I was, however, disappointed. The book is no clearer than the essays about key concepts, such as "elite", "elite capture", "rooms", and what non-elite-captured institutions would look like. It's a short book, but there are many historical anecdotes, which are all overly-intricate. (Some of them are inspiring, but the details simply aren't relevant.) Abstruse philosophy-of-language ideas about conversational "common ground" are invoked to explain phenomena which a few pages later are also explained as mere fear-of-the-consequences, without any recognition of the tension. (There is a big difference between actually creating false consciousness, and merely intimidating people into saying things they don't believe.) It was a mistake to expand the essay to this length, at least in this way.
Now, there is a core idea here which I find persuasive, namely that those with existing advantages will tend to use those advantages to play a disproportionate, even dominating role in any situation, undertaking or movement and to steer it to their advantage, unless pretty severely checked by strong, and enforced, institutional constraints. That's Jo Freeman's "tyranny of structurelessness" (cited by Táíwò), as well as Robert Michel's "iron law of oligarchy" (not cited). So far, so convincing.
But let me push a little. Unless one imagines that everyone in a movement is equally influential, it's mathematically necessary that the most influential members, the elite, are disproportionately influential. (Just build the Lorenz curve of influence.) I admit this pretends that "influence" is a one-dimensional numerical variable, but that'll be true of all sorts of proxies for influence, like time other members of the movement spend attending to you. At what point does this disproportionate influence tip over into "elite capture"? If this is a matter of degrees rather than thresholds, how ought one trade off the bad of elite capture against other desiderata, like actually getting anything done? (Imagine every member of a movement of even 1,000 people speaking for just a minute on a decision, and being listened to.)
These are, of course, very old questions of democratic theory. Liberalism has at least evolved some answers, by now boringly familiar: leadership through formal representation, accountability of representatives to members through regular elections, competition between rival factions of would-be leaders, etc. --- in short, the threat of members throwing the bums out will keep the would-be bums in line. These have their own issues (throwing the bums out can be a collective action problem, which must be preceded by collective cognition), but, at least here, Táíwò doesn't seem to even dismiss the liberal-democratic stand-bys as inadequate, not suited to progressive movements, or what-have-you.
I realize this all amounts to wishing Táíwò had written a different book, but I do. §
(On the question of "identity politics", which actually gets comparatively little space in the book, I can't help boggling at a line Táíwò quotes from Barbara Smith, one of the founders of the Combahee River Collective, explaining why they needed to introduce a new kind of politics in the late 1970s: "We, as black women, we actually had a right to create political priorities and agendas and actions and solutions based in our experiences". The reason I boggle is that was a well-developed political theory in the 1970s which stood solidly behind groups organizing politically to articulate and advance agendas based on their common interests, values and ascriptive identities, including allying with other groups likewise pursuing their agendas. That theory was good old fashioned American interest-group pluralism. If the leading advocates of pluralism lacked the imagination to apply it to black women (or black lesbians, or...), that wasn't a fault in the theory. To be fair, leftist political theory at the time was coming from a place where the only legitimate group to advocate for itself was the organized working class...)
T. Kingfisher, The Twisted Ones
Arthur Machen, The House of Souls
Mind candy, seasonal. The Kingfisher novel begins with a middle-aged person traveling from Pittsburgh to North Carolina to clear out a relative's house and storage unit, a scenario I instantly identified with, and from there builds the strangeness and tension very satisfyingly. It's the first Kingfisher I've read, but it certainly won't be the last.
The Twisted Ones is avowedly based on Machen's short story "The White People", collected in House of Souls, so I finally read Machen. (I previously knew of him just as one of Lovecraft's influences, but, well, there were many, of varying quality.) There's a lot of genuinely good creepy stuff in here, but it's also often hard to tell whether, when Machen mentions nameless abominations, he's talking about genuinely indescribable cosmic horrors, or just being prudish about sex.
Spoiler-y inter-textual commentary for The Twisted Ones: I strongly suspect that some aspects of the visit of our hero to the city of the white people are homages to Lovecraft's At the Mountains of Madness: both feature series of murals depicting the history of the city as its population dwindles over the ages, and the city is ultimately taken over by servitors of the original inhabitants, shoggoths for Lovecraft, and von Neumann-esque self-reproducing magical automata for Kingfisher. §
Cailin O'Connor and James Owen Weatherall, The Misinformation Age: How False Beliefs Spread
Popular social science. The hook here is explaining what the hell has gone wrong with our politics / culture / thoughts in general over the last decade or so. What O'Connor and Weatherall actually do is explain, clearly but carefully, a range of models of social learning and social influence, intended to model how the social organization of a scientific community helps, or hinders, that community's pursuit of truth. (They tend to be Bayesians, and so presume that the truth is always an available option, rather than something that needs to be actually discovered; but I have a thing about this.) In later chapters, they consider how these social processes can be manipulated or subverted by interested parties, especially industrial propagandists. (The last part draws on Oreskes and Conway's great Merchants of Doubt, which I will review Any Year Now). Because of the authors' institutional affiliations, this counts as philosophy of science, but you could equally well see it as theoretical sociology (*). This is all skillfully done.
The last chapter gestures at applying the models to explain why our contemporary information environment is so awful, especially online. I say "gestures" because they don't really try to establish any very serious results here. I don't think they ever even try to document that, in aggregate, people are more mis-informed now than in, say, 1980 or 1960. As I've said before, I have a strong suspicion that the difference isn't the quantity of craziness, but its condensation into blobs of shared insanity. (The proverbial "tin-foil hat brigade" has indeed become a brigade.) If that's true, models of network learning would be a natural candidate to explain the development...
While I have gone on at some length about the last chapter, I am inclined to cut it a lot of slack as mere marketing. Two philosophers writing a non-technical account of social learning in networks, even a very clear and engaging account, might lead to a few course adoptions. (I myself would be very happy to use those chapters in a class on social learning or collective cognition, following their verbal explanations with the technicalities.) Claiming to explain "the misinformation age" will move a lot more copies, which I can't begrudge them. And the phenomena they describe are probably part of the story... §
*: I'd say "sociological theory", but that name is pre-empted by a sort of hazing ritual, in which newcomers are initiated into the tribe by means of textual ancestor worship, and the relative strength of different tribal segments is reflected in exactly which ancestors get worshiped.
Daniel Rigney, The Matthew Effect: How Advantage Begets Further Advantage
This is mostly a rather pedestrian review of literature on sources of cumulative advantage in science, the economy, aspects of democratic politics, and education. There are places where the book is clearly trying to be popular social science, but it just doesn't have the spark, or the clear lines of argument. The one exception is actually the first chapter, on how Robert Merton introduced the term "Matthew Effect", and how it fitted into his larger programs in the sociology of science and general sociology.
I'll keep this around to mine for references, but even those will be increasingly antiquated... §
John H. Goldthorpe, Sociology as a Population Science
On the advice of readers, I have spun off my remarks into a separate review (and expanded them to 800-odd words). §

Books to Read While the Algae Grow in Your Fur; The Progressive Forces; Teaching: Statistics of Inequality and Discrimination; Scientifiction and Fantastica; Commit a Social Science; The Collective Use and Evolution of Concepts; Networks; Philosophy; Cthulhiana; Actually, "Dr. Internet" Is the Name of the Monsters' Creator

Posted at October 31, 2022 23:59 | permanent link

September 30, 2022

Books to Read While the Algae Grow in Your Fur, September 2022

Attention conservation notice: I have no taste, and no qualifications to opine on political sociology or the history of the Second International. Also, most of my reading this month was done at odd hours and/or while bottle-feeding a baby, so I'm less reliable and more cranky than usual.

Robert Michels, Political Parties: A Sociological Study of the Oligarchical Tendencies of Modern Democracy [1911; translated by Eden and Cedar Paul, 1915] [full text via Library of Congress]
I'd read a lot about this book, but the second-hand accounts didn't do it justice. At one level, it's a study of the socialist parties of the Second International during their peak, with the thought being if they couldn't manage to be effectively democratic, controlled by their members rather than their leadership, what hope does any other organization have?
His conclusion is, not much hope at all. And this is the other level of the book, and why it has had a life after 1914.
By a universally applicable social law, every organ of the collectivity, brought into existence through the need for the division of labor, creates for itself, as soon as it becomes consolidated, interests peculiar to itself. The existence of these special interests involves a necessary conflict with the interests of the collectivity. Nay, more, social strata fulfiling peculiar functions tend to become isolated, to produce organs fitted for the defense of their own peculiar interests. In the long run they tend to undergo transformation into distinct classes. [Part 6, ch. 2]
This is the source for the famous "iron law of oligarchy". Paraphrasing: Effective and efficient social groups must employ a division of labor, and must create specialists. Those specialists genuinely know more about how to make the group work than most of its members, and to be effective they need to stay in their roles for extended periods of time, and to be replaced by other specialists. They inevitably become leaders, with different interests than others. Michels: "Who says organization, says oligarchy" [pt. 6, ch. 4].
In terms of what's to be done about this, Michels trembles on the verge of advocating competition among would-be elites and their frequent rotation in office, or at least the threat of their frequent rotation. (He borrows the phrase "circulation of elites" from Pareto, but not quite in the relevant way.) He also trembles on describing democratic control of elites as a collective action problem --- though that's also the sort of thing which people need to organize to solve.
I am not convinced that there's no way out of Michels's dilemmas, that the iron law of oligarchy is as iron as all that. (I have some thoughts.) My gut feeling is that it's like Malthus's iron law of population, or the prisoners' dilemma, or Mancur Olson's ideas about collective action, or Hardin's "tragedy of the commons" --- if you accept the premises, the distressing conclusion does indeed follow. The questions of interest then are when the premises hold, or the ways in which they fail to hold. (Cf., and see footnote *.) That is a major accomplishment, and this is a deserved classic of political thought. §
(Michel's later personal political beliefs, like Pareto's, were deeply unfortunate, to say the least, but are not implied by this book.)
*: Thus Malthus is checked by the industrial revolution and the demographic transition; the prisoners' dilemma by a whole field of the evolution of cooperation; Hardin by Ostrom. (Olson himself emphasized that collective action happens, and the puzzle is understanding how, when and why.) ^
Linda Nagata, Needle
Mind candy science fiction, latest in Nagata's "Inverted Frontier" series. Someone online (name lost, sorry) said the plot outline could easily be that of a Star Trek episode, and I can't quite unsee that (the split-colony parts especially), but it's still very good. In particular it benefits from Nagata's slightly detached and clinical view on these characters and their emotions (which is not very Trek-y at all). §
Michel Talagrand, What Is a Quantum Field Theory?
Talagrand is a probabilist who decided, at the end of a long and distinguished career, that he was finally going to understand what physicists are up to in quantum field theory, and in particular what on earth is going on with calculations that produce infinities somehow being re-jiggered to not produce infinities, a.k.a. "renormalization". This led to an actual mathematician encountering what passes among physicists under the names of "theorems" and "proofs", resulting in a great deal of confusion, exasperation and (reading between the lines) moments of near despair. But it also led to what must be one of the more interesting, and is definitely one of the most personal, books on QFT ever written. Talagrand builds up from scratch all the way to things like \( \phi^4 \) theory, though not covering any serious theory of physical interactions like quantum electrodynamics. But he does succeed in making mathematical sense of a huge part of the framework of QFT, and is frank about where he just can't.
I enjoyed this book tremendously, but I might as well have been reverse-engineered to be its target audience --- I studied QFT as a physics graduate student a quarter century ago (before changing my specialty), and now works in a discipline more affected, or afflicted, by mathematicians' notions of rigor. Whether there are many others who will be similarly interested in 800 pages of careful math being used to do conceptual clarification on one of the more recondite branches of natural science, I couldn't say. §

Books to Read While the Algae Grow in Your Fur; The Progressive Forces; Physics; Mathematics; Scientifiction and Fantastica; Commit a Social Science

Posted at September 30, 2022 23:59 | permanent link

August 31, 2022

Books to Read While the Algae Grow in Your Fur, August 2022

Attention conservation notice: I have no qualifications to opine on early 20th century Russian and Mongolian history, or even on crackpots.

Craig Alanson, Columbus Day and SpecOps
Mind-cotton-candy science fiction. I use the phrase "cotton candy" deliberately: it's pure diverting fluff of no substance whatsoever. I appreciated the diversion, but feel no compulsion to read any further in what is evidently a long series. It did, however, inspire me to re-read William Tenn's magnificent "The Liberation of Earth", which deserves to be retained as a precious part of our common cultural heritage. §
Richard Stark, Nobody Runs Forever
Mind candy crime fiction. This is a Parker novel, which is to say coolly detached competence porn set among professional criminals --- with emotional amateurs providing contrast and heaps of Plot. I found it refreshing. §
James Palmer, The Bloody White Baron: The Extraordinary Story of the Russian Nobleman Who Became the Last Khan of Mongolia
The life and times of an orientalist crackpot who rode the Russian Civil War to enacting a reign of terror in Inner Asia checks so many of my boxes that I have avoided reading this for years, lest it disappoint. Far from doing so, it was a treat. The subtitle is a bit inaccurate (as Palmer explains clearly, there was a khan, and he was a Mongol). But the book itself is clear, amused (when appropriate), humane, learned (when appropriate) and lively. §

Constant readers (if I have any left) will notice that this was not a lot of books. This is because I am now engaged in a very time- and attention- consuming project which will occupy me for the foreseeable future. My collaborator in this endeavor requests that I not blog about it, but I am allowed to describe it by linking to an emblematic image. I like to imagine that the satyr is playing the pipes because he and the nymph have learned that it is, paradoxically, actually the only way to get their baby to sleep.

Books to Read While the Algae Grow in Your Fur; Scientifiction and Fantastica; Pleasures of Detection, Portraits of Crime; Afghanistan and Central Asia; Psychoceramica; Writing for Antiquity; The Running-Dogs of Reaction

Posted at August 31, 2022 23:59 | permanent link

July 31, 2022

Books to Read While the Algae Grow in Your Fur, July 2022

Attention conservation notice:: I have no taste, and no qualifications to opine on the Italian Renaissance, political philosophy, intellectual history, or even game theory.

Niccolò Machiavelli, Selected Political Writings: The Prince, Selections from The Discourses, Letter to Vettori (edited and translated by David Wootton)
I have, of course, no qualifications to opine on translations of Machiavelli, but having worked my way through a fair number of versions of The Prince over the years, this is easily the most-readable one I've run across. (Wootton's introduction, in particular, is a remarkable production in its own right --- I'd say more but I don't want to spoil the effect!) It would be easy to treat these works as mere documents, artifacts illustrating a dead past, of merely-historical relevance. This translation makes them feel remarkably like a part of arguments we could be having right now, maybe are having right now.
Admittedly there is a cost to this --- when Wootton has Machiavelli use contemporary expressions like "political mechanism" or "social structure", I for one am curious about what the actual phrasing was. (If it really was "political mechanism", that'd be very interesting for the history of mechanism, so I suspect it wasn't.) But if I truly cared about that, I could consult other translations, or for that matter the original text. And the difficulties of trying to be more word-for-word literal are well-illustrated by Wootton's practice of parenthetically marking every place where Machiavelli used virtù (or one of its derivatives --- on p. 191 alone this has to be translated as, variously, "skill", "effect" and "will-power".
One thing reading this leaves me pondering is how to interpret The Prince: when (if ever?) was he speaking sincerely; when was he being ironic; when was he unmasking hypocrisy by plainly describing what his contemporaries were doing* (in a spirit I might characterize as somewhere between "I learned it from you" and "you say you want results, I'll tell you how to get results"); when was he using coded, "Aesopian" language to talk safely about dangerous matters; and when was he trying to make himself appear useful to dangerous gangsters and blasphemous grifters in the hopes they'd give him a desperately-needed job? (These are not mutually exclusive and I can well imagine him being especially pleased with himself when passages worked in multiple ways at once.)
The Discourses, by contrast, seem much more straightforwardly sincere. (Unless: maybe that's just what he wanted us to think!) But I will just mention two things which intrigued me. (1) I presume it's well-known to scholars, but new to me, that the famous opening to Gibbon's Decline and Fall about the age of the Antonines is clearly ripped off from elaborating on book I, chapter 10 of the Discourses. (Except for the bits in Gibbon about religion, which are from Machiavelli's book I, chapter 11.) (2) Has anyone written a good comparison between Machiavelli and ibn Khaldun, especially their ideas about institutions, personal character, and cycles of political founding, decay and re-formation? It's very interesting to see two inheritors of ancient political philosophy trying to found a generalizing science of politics based on historical examples, and I'm equally intrigued by the similarities and the differences. (Virtù is not how you say 'asabiyya in Italian, and neither is arete, but...)
This concludes this episode of my nattering about books I am not entitled to judge. §
ObLinkage: Previously on Wootton on Machiavelli.
*: Thus on Ferdinand of Aragon, ch. 21 begins "if you think about his deeds, you will find them all noble", but by the end of the paragraph, "exploiting religion, he practiced a pious cruelty, expropriating and expelling from his kingdom the Marranos: an act without parallel and truly despicable" (pp. 67--68).
Alain Bensoussan, Jens Frehse and Phillip Yam, Mean Field Games and Mean Field Type Control Theory
Mean field games are ones where each player's payoff depends on the distribution of states (or actions) across the other players, not on what any particular individual does. There are some interesting mathematical questions which arise when we consider the limit of an infinitely large population. (Each finite-dimensional individual then confronts the results of their joint actions as an alien and infinite-dimensional force.) In particular, the way large-but-finite-population games converge on infinite-population limits is related to some convergence issues in a long-simmering project, so I have been trying to educate myself about this topic. As part of that self-education, I have tried to explain my current understanding of mean field games more fully in another place.
This short book from 2013 is intended as a sort of crash course in mean field games (and the related mean field control problems). It presumes a lot of familiarity with mathematical control theory, partial differential equations and stochastic differential equations, but less with (e.g.) convergence of stochastic processes or even conventional game theory. In common with, it appears, most of the literature, it limits itself to settings where agents' internal states and exterior actions are all continuous, but it does consider both a single homogeneous population of agents, and the setting where agents are separated into a fixed number of discrete types (with the population of each type going to infinity together). It was useful for my purposes, which was giving me some orientation to the literature, but I imagine there must be better introductions now available.
If you are the sort of person who finds this intriguing, the odds are very good that you have access to the electronic version from the publisher, which is honestly probably all you need. §
Don S. Lemons, An Introduction to Stochastic Processes in Physics
This is very much intended as a first book on probability and stochastic processes for physics undergrads, and as such I imagine it'd work pretty successfully. I stopped being a physics undergrad 29 years ago, and will review the book for teachers of this material, not learners. (I.e., I won't explain common jargon.)
Lemons starts with very basic discrete and continuous distributions, spends a lot of time on Gaussians and moment generating functions, including a sketch of using moment generating functions to derive the central limit theorem. He then tries to describe continuous-time Gaussian processes, specifically the Wiener process and the Ornstein-Uhlenbeck processes. The viewpoint is essentially: take a deterministic ordinary differential equation, of the kind we know and love from physics courses, and throw a random-variable term into the right-hand side, i.e., more or less the way Langevin proceeded Back in the Day. (Langevin's key paper is included in translation.)
Lemons does a remarkable job of "solving" such stochastic differential equations by assuming that the solution is a Gaussian process, so all that's needed are the first and second moments as functions of time; getting ODEs for those moments; and solving those ODEs. It is, in short, a heroic attempt to act as though the theory of stochastic processes stopped with Chandrasekhar 1943. (The name "Ito" does not appear anywhere in the text.) Now, in deriving his solutions, Lemons pulls off some tricks which make me think that (unlike some physicists writing about stochastics) he does know Ito calculus, but doesn't mention it explicitly lest he be prosecuted by his less enlightened fellow tribesmen so as to not frighten off the children. I hesitate to say that this is unwise --- I presume that it's worked pedagogically for Lemons --- but what is unwise is not letting the reader know that there is a more advanced, i.e., both more flexible and more internally consistent, theory of SDEs, a theory which is certainly within the ability of physicists to master. (Cf.) In fact, I think that if Lemons had tried to teach Ito calculus to larval physicists, he'd have done a good job, which exaggerates my disappointment.
Over-all, if I had read this when I was in the intended audience, it would probably have done me a lot of good, but now I think my main use for this will be to mine it for examples to use as homework problems the next time I teach SDEs. §
Steven Cassedy, What Do We Mean When We Talk About Meaning?
I have struggled with the expression "meaning of life" for as long as I can remember, because I can't understand how "life" can be something like a message or a sign that means anything (outside of some very special circumstances). Cassedy is similarly puzzled: the way he puts it (I paraphrase a little) is that if someone could say "the meaning of life is X" (not that most people ever fill in X), one should be equally able to say "life means X", and, well, life is not a message or a sign. By a slight extension of this original sense, "meaning" also conveys "intention, purpose", and one could make sense of "the purpose of life is X" or "life is intended to do X", though it raises the question of whose intention or purpose.
What Cassedy does in this book is try to trace the history of how the phrases, and the ideas, of "the meaning of life" and "a meaningful life" became so ubiquitous in English and other languages. The starting point is Greco-Roman and Hebrew antiquity, where, he argues, there is simply no such concept. He then traces its pre-history, through the Christian fathers (especially Augustine) and the early modern period. "The meaning of life", he argues, first emerged in German, in the Romantic period, and spread from there, into English, French and Russian. (He has a convincing-to-me discussion of the German word involved, Sinn, but since my knowledge of German mostly relates to linear algebra and public transit, I am not competent to judge.) The phrase got further popularized in English through translations of the great 19th century Russian authors, especially Tolstoy and Dostoyevsky, who were of course influenced by the German usage. (Again, Cassedy goes over the history and usage of the Russian words translated as "meaning", but I know no Russian at all.)
Finally, he locates the real tipping point in post-war America, in the writings of the immigrant German theologian Paul Tillich, where "meaning" became a way of talking about God without having to affirm, or even explicitly mention, traditional supernatural dogmas --- but also without denying them, either. At the present, he concludes, it is the very slipperiness of "meaning" which makes it so ubiquitous: if people had to spell out exactly what they were trying to say, it would be less effective (and they might realize they don't know themselves what they're saying).
I found this fascinating and drily funny, but then I'm philistine anima-blind reconciled to living in a blind, purposeless universe, the fortuitous product of the concourse of atoms and void, where I get to be one of those safely on shore watching storms at sea lucky enough to not need this particular analgesic. §
Lauro Martines, Power and Imagination: City-States in Renaissance Italy (New York: Knopf, 1979)
This is a learned and gracefully written book which goes into a lot of the details of how Italian city states --- mostly but not exclusively north of Rome --- formed, struggled, were run, and eventually got absorbed (for the most part) into larger polities. I learned a lot about the internal political machinations, especially about institutional devices which, whatever their republican intentions, ended up helping to perpetuate oligarchy. Thus the "power" part.
The "imagination" is the high culture, especially art and humanism. Martines, for his part, sees this as ideology, and ideology in the service of upper class interests. While a lot of that is convincing, there do seem to be two gaps in his argument there. One is that he never grapples with why this art continues to be meaningful to people all over the world, centuries later, in ways which earlier and later art, equally in the service of related upper classes, just isn't. (Cf.) He does, to be fair, raise the parallel issue with humanistic scholarship, and says that the humanists made some "objective" discoveries of lasting value, but doesn't address how that was possible in a basically-ideological enterprise. The other defect, which I suspect is related, is that he doesn't really explain why serving upper class interests in this time and place should have required such an astonishingly large amount of innovation in technique. He's certainly aware of it: his first two pages of illustrations contrast a Florentine painting from the 1270s (basically still Byzantine) with one from 1426 (that might as well be from another world), and he has perceptive things to say about the development of artistic and literary styles. But these two issues --- why there was so much artistic and intellectual innovation, and why we still value the results --- are just not things he really tries to explain.
In the end, Martines gives the impression that he thinks of his subjects, the upper classes of the Italian city states, extraordinary but also horrible, and I can't help think that by the last chapters he was somewhat sick of them, and that in describing the Italian wars that began in 1494 he was (as the saying goes) "rooting for injuries". If so, it's hard not to sympathize. §
(I have not seen the paperback edition [Baltimore: Johns Hopkins University Press, 1988], but I can't find any indication of revisions.)
Fernand Braudel, Out of Italy: Two Centuries of World Domination and Demise (translated by Siân Reynolds from Le Modèle italien [Paris: Éditions Arthaud, 1989], but first published in Italian {Torino: Giulio Einaudi Editore, 1974])
I picked this up because I ran across a cheap copy and had been impressed by my earlier exposure to Braudel. This is wide-ranging and amiable, but I ended it with no clear idea of what Braudel was trying to argue, and very confused by what, exactly, he meant when he referred to something as a historical "problem" --- and he talks about problems incessantly. (And he's weirdly confident about what he knows are exceedingly tenuous estimates of economic conditions.) I half suspect the key to the book is a seemingly throw-away remark in the last chapter that "Everyone thinks for instance that 'France under the Sun King,' Louis XIV, was 'greater' than Francce under de Gaulle, but the 'inferior' France of the 1960s had a population two or three times greater and was many times richer". In conclusion: maybe worth reading if you are studying Braudel himself (or mid-20th-century historiography, etc.). Yes, I fully realize just how presumptuous it is of me to say such a thing. §

Books to Read While the Algae Grow in Your Fur; Writing for Antiquity; Philosophy; Enigmas of Chance; The Dismal Science; Physics

Posted at July 31, 2022 23:59 | permanent link

June 30, 2022

Book to Read While the Algae Grow in Your Fur, June 2022

Attention conservation notice: I have no taste, and no qualifications to opine on the (linked) decay of our infrastructure and our institutions, or to evaluate books on pregnancy (but then neither does that author).

Walter Jon Williams, Lord Quillifer
Mind-candy fantasy, competence-porn division. I very much enjoyed the latest installment in Quillifer's adventures and mis-adventures, but you really need to have read the previous books (1, 2) to get anything out of this. §
Emily Oster, Expecting Better: Why the Conventional Pregnancy Wisdom is Wrong --- and What You Really Need to Know
There are two hooks here. (Neither is that the "conventional pregnancy wisdom" is all wrong.) One is Oster bringing the clarity of decision theory to pregnancy: let the doctors tell us the probabilities of outcomes under various contingencies, then let pregnant women come up with their utilities for those outcomes and decide which risks are worth it. The other hook is that Oster actually understands study design, and pokes at the medical literature on pregnancy and child-bearing to see which bits of it can support any weight. I am much more persuaded by the second part than by the first, if only because I had independently read a bunch of the same studies Oster and came to similar evaluations. The medical literature isn't all on a level with the Journal of Evidence-Based Haruspicy, but a surprisingly large part of it comes shocking close. I'm sure there are real obstacles to doing better, but it wouldn't hurt the medical system to admit how little confidence they ought to have.
As for the decision theory, well, I just defy anyone to actually implement that ideal. To repeat a favorite anecdote from the great Persi Diaconis:
Some years ago I was trying to decide whether or not to move to Harvard from Stanford. I had bored my friends silly with endless discussions. Finally, one of them said, "You're one of our leading decision theorists. Maybe you should make a list of costs and benefits and try to roughly calculate your expected utility." Without thinking, I blurted out, "Come on, Sandy, this is serious."
That said, I did appreciate Oster's efforts at providing actual estimates of various probabilities, however imperfect. §
ObLinkage1: I am sure this will cause all kinds of awkwardness at the farmers' market. I find the criticisms of Oster in that essay unfair, despite agreeing that public policy is needlessly mean and has, in many ways, grown meaner over my lifetime. The flaws of public policy around parenting, pregnancy, etc. are not Oster's fault; they're not even the economists' fault collectively; it seems fine to not go into policy in a book of advice to prospective mothers, even if you think policy is very important.
ObLinkage2: This puts many of Oster's anecdotes about her own mother in a different (and more impressive) light.
NoLinkage: I am vaguely aware that Oster has made herself controversial with ideas about how to respond to the pandemic. I haven't followed that, I have no opinion on it, I don't see how it's relevant (one way or the other) to this book, and I don't intend to learn anything about this matter, if I can help it.
Chris Raschka, Charlie Parker Played Be Bop
I thank Dmitri Tymoczko for bringing this to my attention.
Chris Ferrie and Marco Tomamichel, Blockchain for Babies
I blame Dmitri Tymoczko for bringing this to my attention, and will not dignify it with a purchase link.
Thomas Thwaites, The Toaster Project: Or a Heroic Attempt to Build a Simple Electric Appliance from Scratch
What it says on the label: an art student tries to build a toaster, from raw materials sourced from Great Britain. Whether he succeeds is a matter of interpretation, but many valuable lessons about technology, knowledge, materials, the division of labor in society, and the nature of the built environment are learned along the way. Recommended if you can enjoy, or even just tolerate, wry, self-deprecating, Very British humor. §
Anna Clark, The Poisoned City: Flint's Water and the American Urban Tragedy
I think it's fair to say that this is the standard account of the Flint disaster, and it should be: it's well-written, impassioned, meticulous without being overwhelming, and provides a lot of important context. That said, there are a few points where I want to push back a little on some things Clark seems to imply.
  1. In Flint, when ordinary people complained that their water was bad, blamed it for all sorts of mysterious medical complaints, and disbelieved official reassurances, the plain people of Flint were, in fact, right. But when ordinary people complain about MMR or Covid vaccines, blame them for all sorts of mysterious medical complaints, and disbelieve official reassurances, they are very, very wrong. (Anyone taking this as an occasion to send me anti-vax rubbish will be piped to /dev/null.) I don't expect Clark to give us the tools to differentiate between these two cases, in a principled way which could help readers going forward --- she's a journalist, not a prescriptive social epistemologist! But I do wish her writing showed some awareness of this pitfall of celebrating the wisdom of the common folk.
  2. Relatedly, "hundreds of protesters bang[ing] on the locked doors of the ornate capitol building, shaking its wood panels" as the legislature tries to go about the ordinary business of democratic self-government (p. 167) --- well, that registers a little differently now, doesn't it?
Let me re-iterate that this is a really good book, which I strongly recommend. §

Books to Read While the Algae Grow in Your Fur; Natural Science of the Human Species; The Beloved Republic; The Continuing Crises; The Great Transformation; Scientifiction and Fantastica

Posted at June 30, 2022 23:59 | permanent link

June 21, 2022

Upcoming Talk: "Matching Random Features"

Attention conservation notice: You have better things to do with an hour of your precious, finite life than staring at a screen while an academic tries to give a hand-wavy summary and advertisement for technical work on abstruse problem you don't care about.

I will be talking on Random-Feature Matching to the One World Approximate Bayesian Computation Seminar at 8:30 am Eastern time (=1:30 pm UK time) on Thursday, 23 June. If you are interested in simulation-based inference but have not (oddly) read my paper, or if you just want to marvel at how bad someone can be at giving a Zoom talk, two years on, please join. (Details on getting access to the Zoom session can be had by following that last link.)

Let me take this opportunity to thank the organizer both for the invitation, and for not insisting on the usual seminar time of 9:30 am UK time.

Self-centered; Enigma of Chance

Posted at June 21, 2022 14:11 | permanent link

Three-Toed Sloth