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

Course Announcement: "Statistics of Inequality and Discrimination" (36-313)

Attention conservation notice: Advertisement for a course you won't take, at a university you don't attend, in which very human and passionately contentious topics deliberately have all the life sucked from them, leaving only the husk of abstractions and the dry bones of methodology.

In the fall I will, again, be teaching my class on inequality

36-313, Statistics of Inequality and Discrimination
9 units
Time and place: Tuesdays and Thursdays, 1:25 -- 2:45 pm, in Wean Hall (WEH) 6403 (tentatively)
Description: Many social questions about inequality, injustice and unfairness are, in part, questions about evidence, data, and statistics. This class lays out the statistical methods which let us answer questions like Does this employer discriminate against members of that group?, Is this standardized test biased against that group?, Is this decision-making algorithm biased, and what does that even mean? and Did this policy which was supposed to reduce this inequality actually help? We will also look at inequality within groups, and at different ideas about how to explain inequalities between groups. The class will interweave discussion of concrete social issues with the relevant statistical concepts.
Prerequisites: 36-202 ("Methods for Statistics and Data Science") (and so also 36-200, "Reasoning with Data"), or similar with permission of the instructor

Last year was the first time I got to teach it, and it was a mixed experience. The students who stuck with it were, gratifyingly, uniformly very happy with it (and I am pretty sure they learned a lot!). But it also had the biggest "melt" of any class I've taught, with fully half of those who initially signed up for it eventually dropping it. The most consistent reason why --- at least, the one they felt comfortable telling me! --- was that they were expecting something with a lot more arguing about politics, and a lot less math and data analysis. I have taken this feedback to heart, and decided to do even more math and data analysis.

Tentative topic schedule

Slightly more than one week per. A more detailed listing, with related readings, can be found on the class homepage.
  1. "Recall": Reminders about probability and statistics: populations, distribution within a population, distribution functions, joint and conditional probability; samples and inference from samples.
  2. Income and wealth inequality: What does the distribution of income and wealth look like within a population? How do we describe population distributions, especially when there is an extreme range of values (a big difference between the rich and poor)? Where does the idea of "the 1%" wealthy elite come from? How has income inequality changed over recent decades?
    Statistical tools: measures of central tendency (median, mode, mean), of dispersion, and of skew; measures of dispersion (standard deviation etc.); measures of concentration and inequality (ratios between percentiles, the Lorenz curve, Gini coefficient); the concept of "heavy tails" (the largest values being orders of magnitude larger than typical values); log-normal and power law distributions; fitting distributions to existing data; positive feedback, multiplicative growth and "cumulative advantage" processes.
  3. Speed-run through social and economic stratification: Reminders (?) about social concepts: ascriptive and attained social statuses, and qualitative/categorical vs. more-or-less dimensions of differentiation. Important forms of differentiation, including (but not necessarily limited to): sex, gender, income, wealth, consumption, caste, race, ethnicity, citizenship, class, order, education. The legal notion of "protected categories".
  4. Income disparities: How does income (and wealth) differ across groups? How do we compare average or typical values? How do we compare entire distributions? How have income inequalities by race and sex changed over recent decades?
    Statistical tools: permutation tests for differences in mean (and other measures of the average); two-sample tests for differences in distribution; bootstrapping; inverting tests to find the range of differences compatible with the data; the "analysis of variance" method of comparing populations; the "relative distribution" method of comparing populations
  5. Explaining, or explaining away, inequality: To what extent can differences in outcomes between groups be explained by differences in their attributes (e.g., explaining differences in incomes by differences in marketable skills)? How should we go about making such adjustments? Is it appropriate to treat discrimination as the "residual" left unexplained? When does adjusting or controlling for a variable contribute to an explanation, and when is it "explaining away" discrimination? What would it mean to control for race, sex or gender?
    Statistical tools: Observational causal inference; using regression to "control for" multiple variables at once, with both linear models and nonparametrically (by means of matching or nearest-neighbors); using graphical models to represent causal relations between variables; how to use graphical models to decide what should and what should not be controlled for; the causal model implicit in decisions about controls.
  6. Detecting discrimination in hiring, admissions, etc.: Do employers discriminate in hiring (or schools in admission, etc.)? How can we tell? When are differences in hiring rates evidence for discrimination? How do statistical perspectives on this question line up with legal criteria for "disparate treatment" and "disparate impact"?
    Statistical tools: tests for differences in proportions or probabilities; adjusting for applicant characteristics (again)
  7. Inequalities in health, disease and mortality: Quantifying differences in the incidence of diseases, in death rates, and in life expectancy. The "deaths of despair" controversy.
    Statistical tools: differences in proportions and probabilities again; survival analysis and survival curves; some of the elements of demography.
  8. Mobility and Transmission of Inequality: What does it mean to talk about social mobility? Conversely, what doe it mean to say inequality can be transmitted from one generation to the next? What are the mechanisms this happens through? What are the large-scale patterns about mobility and transmission, over the last few decades?
    Statistical tools: correlations; conditional probability modeling; Markov models.
  9. Measuring segregation: What do we mean by "segregation"? Segregation in law ("de jure") and segregration in fact ("de facto"). Different ways of measuring de facto segregation. Trends in de facto racial segregation since the end of de jure racial segregation. Why different measures of segregation give different results. Segregation by income. Segregation by political partisanship. Consequences of segregation. Inter-generational transmission again.
    Statistical tools: Standard measures of segregation; more recent measures of segregation based on information theory; spatial correlation; how do we make adjustments for changing distributions?
  10. Algorithmic bias and/or fairness: Can predictive or decision-making algorithms be biased? What would that even mean? Do algorithms trained on existing data necessarily inherit the biases of the world? What notions of fairness or unbiased can we actually implement for algorithms? What trade-offs are involved in enforcing different notions of fairness? Are "risk-prediction instruments" fair?
    Statistical tools: Methods for evaluating the accuracy of predictions; differential error rates across groups; decision trees; optimization and multi-objective optimization.
  11. Standardized tests: Are standardized tests for school admission biased against certain racial groups? What does it mean to measure qualifications, and how would we know whether tests really are measuring qualifications? What does it mean for a measurement to be biased? When do differences across groups indicate biases? (Disparate impact again.) Why correlating outcomes with test scores among admitted students may not make sense. The "compared to what?" question.
    Statistical tools: Predictive validity; differential prediction; "conditioning on a collider"
  12. Intelligence tests: Are intelligence tests biased? How do we measure latent attributes? How do we know the latent attributes even exist? What would it mean for there to be such a thing as "general intelligence", that could be measured by tests? What, if anything, do intelligence tests measure? What rising intelligence test results (the Flynn Effect) tell us?
    Statistical tools: correlation between test scores; factor models as an explanation of correlations; estimating factor values from tests; measurement invariance; alternatives to factor models; item response theory
  13. Measuring attitude and prejudice: How do we measure people's feelings about different groups? Why do different measures give different results? Do "implicit association tests" measure unconscious biases? What, if anything, do implicit association tests measure?
    Statistical tools: More on measurement; the distinction between reliability and validity; why it's much easier to quantify reliability than validity; approaches to "construct validity".
  14. Evaluating inequality-reducing interventions: If we try to do something to reduce inequality, how do we know whether or not it worked? How do we design a good study of an intervention? How do we pool information from multiple studies? What can we do if only bad studies are available? Do implicit bias interventions change behavior? Does having a chief diversity officer increase faculty diversity? What does, in fact, seem to work?
    Statistical tools: Design and analysis of studies; experimental design: selecting measurements of outcomes, and the importance of randomized studies; meta-analytic methods for combining information
  15. Policing and crime: When do differences in traffic stops, arrests, or police-caused deaths indicate discrimination? How do we know how many traffic stops, arrests and police-caused deaths there are to begin with? Does "profiling" or "statistical discrimination" make sense for the police, whether or not it's socially desirable? How can the same group be simultaneously over- and under- policed?
    Statistical tools: test for differences in proportions; signal detection theory; adjusting for systematically missing data; self-reinforcing equilibria
  16. Self-organizing inequalities and "structural" or "systematic" inequalities: Models of how inequalities can perpetuate themselves even when nobody is biased. Models of how inequalities can appear even when nobody is biased. The Schelling model of spatial segregation as a "paradigm". How relevant are Schelling-type models to actual, present-day inequalities?
    Statistical tools: Agent-based models; models of social learning and game theory.
  17. Statistics and its history: The development of statistics in the 19th and early 20th century was intimately tied to the eugenics movement, which was deeply racist and even more deeply classist (but also often anti-sexist). The last part of the course will cover this history, and explain how many of the intellectual tools we have gone over to document, and perhaps to help combat, inequality and discrimination were invented by people who wanted to use them for quite different purposes. The twin learning objectives for this section are for students to grasp something of this history, and to grasp why the "genetic fallacy", of judging ideas by where they come from (their "genesis") is, indeed, foolish and wrong.
    Statistical tools: N/A.
  18. How do we know what we do about inequalities? Social data-collection systems and institutions. Measurement again, and measurement as a social process. Difficulties in reducing social reality to data; the case of race in the US census as an example. What systematic data collection leaves out.


There will be one problem set per week; each of these homeworks will involve some combination of (very basic) statistical theory, (possibly less basic) calculations using the theory we've gone over, and analysis of real data sets using the methods discussed in class. There will also be readings for each class session, and a short-answer quiz after each session will combine questions based on lecture content with questions based on the readings.

There will be no exams.

My usual policy is to drop a certain number of homeworks, and a certain number of lecture/reading questions, no questions asked. The number of automatic drops isn't something I'll commit to here and now (similarly, I won't make any promises here about the relative weight of homework vs. lecture-related questions).

Textbook, Lecture Notes

There is, unfortunately, no one textbook which covers the material we'll go over at the required level. You will, instead, get very detailed lecture notes after each lecture. There will also be a lot of readings from various books and articles. (I will not agree with every reading I assign.)

Teaching: Statistics of Inequality and Discrimination; Corrupting the Young; Enigmas of Chance; Commit a Social Science

Posted at June 21, 2022 13:45 | permanent link

May 31, 2022

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

Attention conservation notice: I have no taste, and no qualifications to opine on the archaeology of the Southwest, the pre-history of diversity training, or trends in American economic inequality.

Walter Jon Williams, Metropolitan and City on Fire
These are two novels Williams wrote in the '90s about intrigue and machinations in a world-spanning city, where the geomantic forces generated by covering the planet in concrete, metal and plastic are carefully harvested and metered, and our heroine longs to smash it all. They're some of the best stuff Williams has ever done, which is saying a lot. Strictly speaking, they are fantasy, even "urban fantasy", but very much in the manner of well-thought-through science fiction.
As a character, Aiah has something in common with Williams's Caroline Sula and even (when it comes to learning to lie and manipulate) Dagmar Shaw, but she is her own, vivid and plausible, person.
I last read these in 1999; I re-read them because Williams recently said that the long, long delayed third volume will finally happen. I am very eager. §
John Kantner, Ancient Puebloan Southwest
This is a well-written, semi-popular account of the archaeology of the American Southwest, focusing on the period from the rise of Chaco Canyon to the early years of Spanish rule. The writing is mostly smooth and expository (*), and I learned a lot of fascinating-to-me details from it. Kantner does do the usual archaeologist thing of making very confident-sounding assertions about social organization which he must know are far more conjectural than he makes them sound. (**) But this is par for the archaeological course. If you have a non-expert interest in the subject, and can handle the lack of a definite article in the title, this is a worthwhile book. I would read a second edition. §
*: Though inconsistently so; he explains "inference", but not "dendrochronology" or "palynological". --- On a different plane, Kantner persistently writes "inequity" (an evaluative, qualitative judgment) when he should write "inequality" (a descriptive and quantitative comparison). Unless, that is, he regards every inequality as inequitable, which is his right but not something to be just assumed... ^
**: To paraphrase, he does things like assert that a division of such-and-such a community into "moieties" can be inferred from the construction of a wall dividing a building in two. Or, again, there are assertions that a one community couldn't have politically dominated another because the latter kept making pots in its old way. This sort of thing just shows a failure of imagination. (I used to part-own a house that had been built for one large family around 1900, and later split with a wall down the middle. While Pittsburgh has some peculiarities it does not divide duplex residents into two endogamous groups, so that I am expected to regard all North-Halfers as some kind of kin.) It also, I think, betrays a failure to check this sort of inference against cases where much more is known about society and politics from written records. ^
Elisabeth Lasch-Quinn, Race Experts: How Racial Etiquette, Sensitivity Training, and New Age Therapy Hijacked the Civil Rights Revolution (2001)
This is, obviously (?), a work of cultural criticism, but it's done with the tools of a serious historian who is trying to excavate where things like diversity training came from, and why they both emerged when and where they did, and how they survived that initial context. To oversimplify and exaggerate: the late 1960s/early 1970s were a weird time, when plenty of people on the fringes of psychology felt entitled to make stuff up because it sounded good and vibed with their politics, with very little reality-testing. Add the "triumph of the therapeutic" and of self-esteem, plus corporate concerns to ward off liability by claiming to do something (however ineffective), plus the continuing attraction of racialist thinking under another guise (*), and we get a mess.
There are, equally obviously, some political and ethical commitments animating this book, but they are transparent, and honestly ones I have a lot of sympathy for, even if I suspect she and I would often disagree on concrete policies. I would pay very good money to read Lasch-Quinn writing seriously about 2020; unfortunately this is not the kind of work which can be done that quickly, and anyway she seems to have moved on to other topics. §
*: Lasch-Quinn does not use phrases like "reinscribing an essentialized racial binary", but they would actually fit her argument.
Elizabeth Kolbert, Under a White Sky: The Nature of the Future
A collection of journalistic essays. The formula each time is Kolbert visiting some place --- an electrified anti-invasive fish barrier on the reverse-flowing Chicago river, the mouth of the Mississippi, a cave in the Nevada desert where a unique native fish species is being quixotically maintained, the Great Barrier Reef, a carbon-sequestration site in Iceland --- where she can see (as the saying went) "the Earth as transformed by human action", and talk to the workers. Often enough, the reason these efforts are necessary are dealing with side-effects of earlier efforts at control, which Kolbert presents as ironic but unavoidable; we've gone too far down this path to turn back now. (Though she doesn't say so, we'd gone too far when Gilgamesh was king in Uruk.) Stewart Brand is quoted, aptly; so is John McPhee's classic The Control of Nature.
Speaking of McPhee: this is one of the most New Yorker-y books I've ever read. It has all the characteristic virtues: easy prose, lively (but not startling) intelligence, an eye for detail expressed through original (but not outlandish) metaphors, judiciously-chosen historical anecedotes, sympathetic if amused pen-portraits of interesting characters; you come away feeling like you've understood something, without having been taxed. I realize my description may sound a bit barbed, because it is. On the one hand, I want to acknowledge how hard such writing is to pull off --- being scholarly and exhaustive actually takes much less effort and skill --- and record my admiration, indeed my envy. But on the other hand, the reader puts the book down feeling like they've understood something, without necessarily having done so. On the topics where I know enough to think I could judge (mostly having to do with climatology), Kolbert seems accurate, which increases my confidence in the rest of her work. But somehow I was more conscious of the art, and more suspicious of its effects, than I normally am.
This was the first book by Kolbert I've read; I will certainly read more. §
Gino C. Segrè and John D. Stack, Unearthing Fermi's Geophysics
This is a perfectly nice little introduction to geophysics, suitable for third- or fourth- year physics majors. (That is, you are expected to have forgotten undergraduate classical mechanics, thermo, and E& M; fluid and continuum mechanics are introduced here as needed.) The hook here is that this is based on the notes for such a course which Fermi taught, and which Segrè discovered in the archives. Of course it has been vastly fleshed out (the authors reproduce selected pages from Fermi's notes, and "telegraphic" hardly does it justice), and there are a few places where it's been brought up to date, primarily by comparing Fermi's numerical figures with modern measurements. There is thus no discussion of continental drift or of climate change, to name just two important topics. Still, I enjoyed the gimmick, and it's a nice introduction to interesting and important topics in physics. I would imagine that it would suffer, in terms of classroom use or even serious self-study, from lacking exercises. (It would be very interesting to see Fermi's idea of good homework problems!) §
Rebecca M. Blank, Changing Inequality
This is essentially a huge exercise in comparing the American Community Survey's economic statistics in 1979 with those in 2007. The headline is that households at (almost) every level had substantially higher incomes in 2007 than in 1979, even after making all kinds of allowances for changes in the cost of living (*). There was also vastly more inequality, particularly but not only towards the top.
The thing which makes this book more interesting than that sounds is the way Blank does very careful comparisons --- she calls them "simulations" --- why try to tease out the factors which have contributed to these shifts (**). Thus she tries to work out how much of the changes in typical incomes and in measures of inequality can be explained by changes in family structure, by changes in labor-force participation, by changes in income by education level, etc., leaving other factors at their 1979 values. Thus she can give answers to questions like "How much richer-but-unequal would we be just from our being more educated, if salaries and marriage patterns still looks like 1979?" Or, rather, she can give reasonable but still conjectural answers to such questions; any sort of counterfactual assertion rests on untestable hypotheses.
To summarize, much of the increase in typical household incomes comes from increased female labor-force participation. Some of the increase inequality is related; it comes from the increased tendency of highly educated men to be married to highly educated women who also work in well-paid jobs. But lots of the increasing inequality, which takes the form of higher household incomes increasing much faster than those at the median (or even the 80th percentile...) can't be explained in these ways. These findings in turn let Blank say some sensible things about how different policies might reduce inequality. (One finding, at first startling, is that bringing every poor household up to the poverty line would actually do very little to reduce inequality by any of the usual metrics.)
This isn't a scintillating read, but it's serious, sober and (as we used to say) reality-based. I read it in part as fodder for my inequality class, and I am seriously considering having The Kids do (simplified) versions of Blank's comparisons. If you have a serious concern with economic inequality, or social change in America since the 1970s, this is very worth reading. §
*: One important limitation to this conclusion, which Blank duly acknowledges, comes with this data. Because the ACS doesn't track households from one year to another, it doesn't let us saying anything about the stability or security of income. In particular, it doesn't let us say whether a household at the median in 1979 could be more confident of staying at the median than their counterparts in 2007. There is evidence that incomes fluctuate more now than they used to, which, if you believe standard economic theory, would reduce the value of any given level of income. ^
**: Mathematically, I think what she does amounts to a piece-wise constant approximation of Handcock and Morris's "relative distribution" method, which was also invented for studying shifts in inequality. But I haven't ground through the algebra and there might be subtle differences. ^
A. M. Stuart, Singapore Sapphire, Revenge in Rubies, Evil in Emerald
Mind-candy historical mysteries, set in Singapore, mostly among just-barely-genteel Britishers, in the years immediately before World War I. Enjoyable period color, though family tradition requires me to make dark aside about British imperialism as I read. §

Books to Read While the Algae Grow in Your Fur; Scientifiction and Inequality; The Dismal Science; Writing for Antiquity; Commit a Social Science; The Progressive Forces; Teaching: Statistics of Inequality and Discrimination; Pleasures of Detection, Portraits of Crime; Tales of Our Ancestors; Physics; The Great Transformation; Biology

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

May 28, 2022

Don't @ Me

Attention conservation notice: Rationalizing my gut-level dislike of a social medium as Objectively Correct. First drafted in mid-2017, left to rest in my drafts folder because, while sincere, it feels a bit mean. Posted now because I found myself re-writing the next-to-last paragraph.

If, as Leibniz has prophesied, libraries one day become cities, there will still be dark and dismal streets and alleyways as there are now. --- Lichtenberg
I mentioned, some years ago, that in response to reader requests I have a Twitter account. I use this only for announcing new posts here. Messages sent to it will go unread; attempts to communicate through it will be fruitless.

I have, nonetheless, put some time over the years into observing Twitter; I wish I had it back again. There are, so far I can see, only four good uses for Twitter:

  1. Announcements of actual, substantive posts, resources or discussions elsewhere. (But we have e-mail and RSS already.)
  2. Announcing off-line events, details given elsewhere.
  3. Snapshots of cute animals, pretty landscapes, children's birthday parties, and the like.
  4. Jokes.

For everything else, well, if someone had deliberately tried to combine the worst features of comments sections and Usenet, they could hardly have done better --- except by first imposing silly length restrictions, followed by kludged-on threads that make Usenet seem a model of clear organization, plus of course an interface that channels people towards the outrage (or main character) of the moment.

I don't know whether it makes people unhappy and angry, or whether only unhappy, angry people persist in using it, but I am not joking when I say that we would all be better off if it disappeared immediately.

--- One of my long-held semi-crank notions is this: all online communication, being through writing, reproduces the social dynamics of literary communities, especially print-literary communities. This law holds independent of the educational level or even intellectual seriousness of the participants. Thus flame-wars, sock-puppets, selective quotation, trawling through the archive for discreditable episodes, "the lurkers support me in e-mail", creating isolated fora to incubate increasingly weird ideas, recycling from supposedly-authoritative source texts long after they're debunked (if they were ever bunked in the first place), spastic attention cascades in which "all fandom was plunged into war", etc., escape from the pages of the little magazines (such as the Philosophical Transactions of the Royal Society), to become part of everyone's life. Twitter has raised this to a new level of awfulness, by making it very hard to actually contribute anything of value, or, having done so, for others to find it and build on it, while still preserving the affordances for weirdness, meanness, and spasm-proneness.

That is my opinion; and it is further my opinion that you people should get off my lawn.

Update, 28 May 2022, further to the theme, in no particular order:

*: Some comments on Frost's review, without having read the book being reviewed. (1) I am, unsurprisingly, extremely sympathetic to the position that hashtag activism is basically futile. (If the authors really neglect Tufekci's empirical and theoretical work as much as Frost says they do, it's pretty damning.) (2) Not examining right-wing hashtag activism seems like an obvious analytical flaw. (Even if your primary interest is in left-wing movements, the comparisons are essential.) (3) It's true that Twitter isn't accountable to its users, or to the people-as-represented-by-government, but Frost for her part never makes clear which of the flaws she identifies would be remedied by such accountability. (4) Doing something about the opioid epidemic by tinkering with drug policy seems a hell of a lot more practical to me that doing something about it by overthrowing American capitalism, or even reversing the trends in inequality over the last half-century. (I would like to see those trends reversed.) ^

Actually, "Dr. Internet" Is the Name of the Monsters' Creator; Linkage; Modest Proposals; The Collective Use and Evolution of Concepts

Posted at May 28, 2022 12:56 | permanent link

April 30, 2022

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

Attention conservation notice: I have no taste, and no qualifications to opine on U.S. politics, or the lives and works of 20th century Marxist intellectuals.

Charles Willeford, Miami Blues and New Hope for the Dead
Mind candy mystery: First two "Hoke Moseley" mystery novels, written and set in Miaimi c. 1980. They're still funny and satisfying crime fiction, but very much artifacts of a vanished age. (The cover of the in-print edition of Miami Blues is more than usually misleading.) The community-college bits in Miami Blues, and particularly the pontificating English professor, are made more amusing by learning that Willeford's day job was, precisely, being an English professor at a Miami community college. §
Elizabeth Hand, Available Dark
Sequel to Generation Loss, which I re-read. This time around, Cass gets mixed up with the confluence of Nordic death metal, neo-paganism, bizarre art photography, and Iceland's role in the financial crisis of 2008. Stirring this together with drugs, booze, toxic nostalgia and her convincingly awful combination of bad decisions and sudden insight produces truly absorbing Plot.
Something which registered on the re-read of Generation Loss, but which eluded me the first time around: Cass isn't from just any podunk town in upstate New York, but from the literally haunted town in Hand's Black Light, whose inhabitants have made a deal with, if not the Devil, then at least a nasty avatar of Dionysus. I now believe that it is legitimate to take Cass's visions not as [just] drug-induced hallucinations, but factual descriptions of supernatural experiences. In particular, I think Cass is, if not exactly a valkyrie or banshee, then something in that line, a walking, talking, bourbon-and-meth-swilling, shutter-happy harbinger of doom, and the birds know it. All of which said, these books are eminently enjoyable on a "straight", non-fantastic level, which is a neat trick.
I eagerly look forward to her further mis-adventures. §
Graydon Saunders, A Succession of Bad Days
Mind candy fantasy, the sorcerors' apprenticeship division: 900-or-so pages of the education of wizards, in the same world as Saunder's The March North, with detailed thermodynamics. (It's not called thermodynamics but I dare say anyone who will enjoy this will recognize what is going on.) I did not enjoy this as much as I did The March North, at least in part because all of the characters tend to sound a bit too much the same, i.e., like Saunders. But I enjoyed it enough to keep reading all the way to the end. §
Jennifer Nicoll Victor, Understanding the U.S. Government
The fact that I listened to a course of Poli. Sci. 1 lectures, and learned from them, shows I am not qualified to actually review them. But I enjoyed this. §
Disclaimer: Prof. Victor and I actually collaborated once, in supervising a student project which tried to use social network analysis to get at the question of whether campaign donations affect Congressional outcomes. It was never published because we got null results (and the student moved on to other things). In retrospect, my guess is that resources (including funds) do matter, but that it's rare for disputed issues to have lots of resources on only one side of the dispute (if they did, the dispute wouldn't stay on the agenda for long), and the study wasn't well-positioned to get at the counter-factuals. But, like I said, I learned stuff about how my government works from these lectures, so you probably shouldn't listen to me!
Stanley Pierson, Leaving Marxism: Studies in the Dissolution of an Ideology
Mostly, this is three biographies of three very different intellectuals who all ended up ex-Marxists: Henri de Man, the Belgian advocate of planning and WWWII-collaborator; Max Horkheimer of the Frankfurt School; and Leszek Kolakowski. Pierson emphasizes that, like many Marxist intellectuals, they came from bourgeois backgrounds, were drawn to socialism and to Marxism by its resonance with their bourgeois values, and ultimately left Marxism because of those same values. (He does not inquire into how they differed from intellectuals of bourgeois origins who remained Marxists, or the rare 20th-century Marxist intellectuals from humbler backgrounds like Gramsci.) There are no great revelations here, but they're well-written and well-researched biographical studies. Recommended if you care about intellectuals in politics, or the Marxist tradition. §

Books to Read While the Algae Grow in Your Fur; Scientifiction and Fantastica; Pleasures of Detection, Portraits of Crime; The Progressive Forces; Writing for Antiquity; Commit a Social Science; The Beloved Republic

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

April 25, 2022

Intermittent Finds in Complex Systems and Stuff, No. 2

Attention conservation notice: Links to forbiddingly-technical scientific papers and lecture notes, about obscure corners of academia you don't care about, and whose only connecting logic is having come to the attention of someone with all the discernment and taste of a magpie (who's been taught elementary probability theory).
Or whatever the heck it is I study these days. (I did promise that this series would be intermittent.) In no particular order.
Modibo K. Camara, "Computationally Tractable Choice" [PDF]
I'll quote the abstract in full:
I incorporate computational constraints into decision theory in order to capture how cognitive limitations affect behavior. I impose an axiom of computational tractability that only rules out behaviors that are thought to be fundamentally hard. I use this framework to better understand common behavioral heuristics: if choices are tractable and consistent with the expected utility axioms, then they are observationally equivalent to forms of choice bracketing. Then I show that a computationally-constrained decisionmaker can be objectively better off if she is willing to use heuristics that would not appear rational to an outside observer.
If you like seeing SATISFIABILITY reduced to decision-theoretic optimization problems, this is the paper for you. I enjoyed this partly out of technical interest, and partly to see Simon and Lindblom's heuristic arguments from the 1950s rigorously validated.
One last remark: the slippage of "rationality" in the last sentence of the abstract is fascinating. We started by wanting to define "rational behavior" as being about effectively adapting means to ends; we had an intuition, inherited from 18th century philosophy, that calculating the expectation values in terms of rat orgasm equivalents would be a good way to adapt means to ends; we re-defined "rational behavior" as "acting as though one were calculating and then maximizing an expected number of rat orgasm equivalents"; now it turns out that that is provably an inferior way of adapting means to ends, and we have to worry about what it says about rationality. There's something very wrong with this picture! §
(Thanks to Suresh Naidu for sharing this paper with me.)
Carlos Fernández-Loría and Foster Provost, "Causal Decision Making and Causal Effect Estimation Are Not the Same... and Why It Matters", arxiv:2104.04103
To make an (admirably simple) argument even simpler: Think of decision-making as a classification problem, rather than estimation. If your classifier mis-estimates \( \mathbb{P}\left( Y|X=x \right) \), but you're nonetheless on the correct side of 1/2 (or whatever your optimal boundary might be), it doesn't matter for classification accuracy! So if you over-estimate the benefits of treatment for those you decide to treat, well, you're still treating them...
Ira Globus-Harris, Michael Kearns, Aaron Roth, "Beyond the Frontier: Fairness Without Privacy Loss", arxiv:2201.10408
My comments got long enough to go elsewhere.
Hrayr Harutyunyan, Maxim Raginsky, Greg Ver Steeg, Aram Galstyan, "Information-theoretic generalization bounds for black-box learning algorithms", arxiv:2110.01584
I was very excited to read this --- look at the authors! --- and it did not disappoint. It's a lovely paper which both makes a lot of sense at the conceptual level and gives decent, calculable bounds for realistic situations. I'd love to teach this in my learning-theory class, even though I'd have to cut other stuff to make room for the information-theoretic background.
Adityanarayanan Radhakrishnan, Karren Yang, Mikhail Belkin, Caroline Uhler, "Memorization in Overparameterized Autoencoders", arxiv:1810.10333
I was blown away when Uhler demonstrated some of the results in a talk here, and the paper did not disappoint.
Mikhail Belkin, "Fit without fear: remarkable mathematical phenomena of deep learning through the prism of interpolation", arxiv:2105.14368
Further to the theme.
Nicholas Carlini, Florian Tramer, Eric Wallace, Matthew Jagielski, Ariel Herbert-Voss, Katherine Lee, Adam Roberts, Tom Brown, Dawn Song, Ulfar Erlingsson, Alina Oprea, Colin Raffel, "Extracting Training Data from Large Language Models", arxiv:2012.07805
Demonstrates that from GPT-2 they can extract "(public) personally identifiable information (names, phone numbers, and email addresses), IRC conversations, code, and 128-bit UUIDs", even though "each of the above sequences are included in just one document in the training data".
Some miscellaneous, largely mean, comments:
  • I don't understand why they compare zlib entropy to language-model perplexity, when entropy density is basically log(perplexity). This probably wouldn't make a big difference to any results but it bugged me.
  • This has to be connected to Radhakrishnan et al., right?
  • I'd really like to see someone throw this many parameters, and this much data, at something like Pereira, Singer and Tishby 1996 and see how it does in comparison, both in terms of the usual performance metrics and memorizing random (and inappropriate) bits of the training data. (Pereira may be in a position to do the experiment!)
  • Some people will, of course, interpret this as evidence that GPT-2 knows who you are, and so is that much closer to judging the quick and the dead basilisk-dom being amenable to bargaining under the canons of timeless decision theory.
Gabriel Rossman and Jacob C. Fisher, "Network hubs cease to be influential in the presence of low levels of advertising", Proceedings of the National Academy of Sciences 118 (2021): e2013391118
In a pure social-contagion/diffusion-of-innovations process, the contagion/innovation will spread farther, and spread faster, if it begins at one of the the most central nodes in the network, than if it begins at a randomly chosen node, let alone a deliberately-peripheral one. This motivates a lot of effort in applications to search for influential figures and target them. What Rossman and Fisher do is extend the model very modestly, to model "advertising", i.e., a probability for nodes to contract the contagion / adopt the innovation spontaneously, without direct contact with an infected / adopter node. What they show is that even a very small amount of advertising massively reduces the advantage of beginning at a central node. It's a very convincing, lovely, and potentially-applicable result. I also strongly suspect there's a genuine phase transition here, with the transition point moving towards zero external field as the size of the network goes to infinity, but I haven't been able to show that (yet). --- Many thanks to Prof. Rossman for presenting this paper to CMU's Networkshop.
Yuan Zhang, Dong Xia, "Edgeworth expansions for network moments", arxiv:2004.06615
This is technical, but valuable for all of us interested in being able to quantify uncertainty in network data analysis, especially in those of us working graph-limits/graphons/conditionally-independent-dyads framework. --- Thanks to Prof. Zhang for a very enjoyable conversation about this paper during a "visit" to Ohio State via Zoom.
David Childers, "Forecasting for Economics and Business"
Great materials for an undergraduate economics course (73-423) at CMU. Thanks to David for the pointer.
Vera Melinda Galfi, Valerio Lucarini, Francesco Ragone, Jeroen Wouters, "Applications of large deviation theory in geophysical fluid dynamics and climate science", La Rivista del Nuovo Cimento 44 (2021): 291--363, arxiv:2106.13546
The laws of large numbers say that, on large enough scales, random systems converge on their expected values. ("Large scales" here might indeed be number of samples, or length of time series, or something similar.) In symbols which you should not take too literally here, as \( n \rightarrow \infty \), \( \mathbb{P} \left( |A_n - a_{\infty}| > \epsilon \right) \rightarrow 0 \) for every \( \epsilon > 0 \), where \( a_{\infty} \) is the limiting behavior of the process. Large deviations theory is about fluctuations away from the expected behavior, and specifically about finding rate functions \( r \) such that \( \mathbb{P} \left( |A_n - a_{\infty}| \geq \epsilon \right) \sim \exp{\left( -n r(\epsilon)\right) } \). This is a "large" deviation because the size \( \epsilon \) is staying the same as \( n \) grows. We'd anticipate seeing this kind of behavior if \( A_n \) was the result of some number \( \propto n \) of independent random variables, all of which had to cooperate in order to produce that \( \epsilon \)-sized fluctuation. More specifically, a good point-wise rate function will let us say that \[ \frac{1}{n}\log{\mathbb{P}\left( A_n \in B \right) } \rightarrow - \inf_{x \in B}{I(x)} \] so that, as the saying goes, an unlikely large deviation is overwhelmingly (exponentially) likely to happen in the least unlikely possible way. Large deviations theory gives us lots of tools for calculating rate functions, and so saying how unlikely various large deviations are (at least to within asymptotic log factors), and for characterizing those least-unlikely paths to improbable events. (I am glossing over all kinds of lovely mathematical details, but follow some links.)
Now climate systems contain a lot random variables, which are mostly tightly dependent on each other but not completely so. And a lot of what we should worry about with climate comes from large fluctuations away from typical behavior. (E.g., transitions from one meta-stable state of the climate, where, say, there is a Gulf Stream in the North Atlantic keeping western Europe warmer than Labrador or Kamchatka, to another meta-stable state where there is not.) So climate modeling is actually a very natural application for large deviations theory. This is a well-written review paper surveying those applications, with a minimum of mathematical apparatus. (The implied reader does, however, remember fluid mechanics and thermodynamics.) It makes me want to learn more about rare-event simulation techniques. §

Complexity; Enigmas of Chance; Networks; Physics; The Dismal Science; Constant Conjunction Necessary Connexion; Automata and Calculating Machines

Posted at April 25, 2022 10:41 | permanent link

Positive-Definite Tab Closure

Attention conservation notice: A link-dump piece, where some of the links were first opened in 2015.

Tabs I have closed recently, which are of a positive and/or constructive and/or cheerful nature:

(I am sure that I am forgetting to credit sources for these links, and can only plead for forgiveness.)

Linkage; Psychoceramica; Physics; Natural Science of the Human Species; Mathematics; Automata and Calculating Machines; The Commonwealth of Letters; Biology

Posted at April 25, 2022 10:40 | permanent link

March 31, 2022

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

Attention conservation notice: I have no taste, and no credentials to opine on the sociology of education, political and moral philosophy, medieval Islamic science, or even, strictly speaking, pure mathematics.

Dana Stabenow, A Cold Day for Murder, A Fatal Thaw, Dead in the Water, A Cold-Blooded Business, Play with Fire
Mind candy mysteries, where the Alaskan environment is as much a character as any human being, or husky. Stabenow was, I believe, originally a science fiction and fantasy writer, and I think some of that comes through in the way the very strange world of Alaska is unfolded before the reader. It also comes through in the character of Kate Shugak, a hero of basically-royal birth who lives on the border between civilization and the wilderness, and who roams the countryside defeating monsters and malefactors, especially those who have offended against the laws of kinship and hospitality. (There are a lot of explicit references to Greek myths and I do not believe any of this is coincidence or even unconscious.) The fact that I read five of these in a month, and have more in the queue, tells you how easily they go down. §
Douglas B. Downey, How Schools Really Matter: Why Our Assumption about Schools and Inequality Is Mostly Wrong
I am not sure what to make about this one.
Downey studies some nationally-representative longitudinal data sets, which measure student achievement in reading and math at multiple points in the school year, over multiple years. "Longitudinal" here means that each student is being measured multiple times, allowing one to draw inference about how much was learned when. The basic finding Downey extracts from this is that during the school year, richer and poorer students, and black and white students, learn at basically the same rate. But they arrive at school at very different average levels of achievement, and their gaps grow while out of school each year. Thus, on this evidence, schools for the disadvantaged are in fact doing about as well at teaching reading and math as other schools. The inequality in educational outcomes, then, isn't due to inequality in schooling, but to (as Downey puts it) the other 87% of students' lives.
This is remarkably contrary to received opinion, what Downey calls "The Assumption", that schools for the poor are poor schools which do not teach effectively. I get the impression that Downey started by wanting to be talked out of this position, but came to embrace it for lack of intelligent opposition:
I don't think that the people questioning the evidence are bad people, but they are reluctant to let go of the dominant narrative about schools. It would be one thing if the reason was because they had issues with whether the ECLS-K item-response theory scales of reading can be considered truly interval, or if they questioned whether nonschool investments in children are constant across seasons, or if they thought that the approach scholars use to model the overlap days between test dates and the beginnings and ends of school years was insufficient. ... But while many have resisted the empirical patterns in chapters 1--4 and remain committed to The Assumption, the quality of evidence doesn't seem to be the obstacle. [p. 97]
I join Downey's audiences in astonishment. I also join him in thinking that "we really need to reform the distribution of rewards in the broader society", but I just have a hard time swallowing the findings. (Among other things, if he's right, why are parents so convinced otherwise?) But I also don't have any clever explanations to make this pattern in the data into a mere artifact. As a statistician, I do wonder about whether these surveys really cover a nationally representative sample of students and schools. (Though it's hard to imagine what sort of sampling bias would produce this pattern!) There is also the issue (which Downey highlights in the quote above) of whether these reading and math scores are really "interval". Concepts like "median" make sense with merely ordinal variables, but something like "the change in the median poor kid's reading score from September to May is equal to the change in median scores for rich kids", \( X_p(2) - X_p(1) = X_r(2) - X_r(1) \), needs us to be able to compare differences at arbitrary points along the scale. So this is resting a lot on the ways the survey researchers translate students' answers into numerical values, and I'd have liked to see a lot more about that. In particular I'd want to make really sure that this sort of parallel trajectories isn't an artifact of the scaling procedure.
It is unlikely, but not I guess impossible, that I will actually investigate this properly. In the meanwhile, I am informed, but puzzled and unsettled. §
(Text lightly edited 3 June 2022, to resolve some ambiguous pronouns etc.)
Update, 3 July 2022: a favorable review in the American Journal of Sociology.
Jürgen Jost, Postmodern Analysis
I should begin by admitting that I took real analysis as a sophomore, scraped out a C through the kindness of the teacher, and became a physicist. (I did eventually learn measure-theoretic probability.) So the idea of anyone taking advice from me on pure math textbooks is preposterous.
I should also say that I met Jürgen through Santa Fe more than twenty years ago, admire his work on information geometry and complex systems, have given talks at the Max Planck Institut he directs, etc. If I read one of his books and didn't like it, I'd just say nothing publicly.
With my throat now hopefully adequately cleared: When we all went home in March 2020, I got the idea that this would be when I finally learned some important areas of math properly. This fantasy led to downloading a large number of books from the library, and discovering that I would never read most of them for good reason. But this one I stuck with. It's a really good survey of crucial topics in analysis, starting with the basics of differentiation and Riemann integration, visiting things like ordinary differential equations as dynamical systems, Lebesgue integration, and function approximation, and ending up with the calculus of variations and partial differential equations and their interconnections. It's "postmodern" only in the sense that it comes after the classical works on modern analysis of the mid- / late- 20th century, and tries to give a survey of what a bright young mathematician should know now. The exposition is great, consistently just rigorous enough that I needed to inhibit my lizard-brain physicist impulses ("it'd be nice if that equation had a square-integrable solution, therefore it does"), but always with an eye on applications, i.e., on reality. It's really quite enjoyable, and makes me want to read Jost's other textbooks. §
(The obvious question is whether I would have done any better, as an undergrad, if this had been the text in my real analysis course. Honesty compels me to say: "not on your life"; our textbook was forgettable but decent, the problem was teenage me.)
Final disclaimer: I read the second (2003) edition; the third (2005) edition seems to mostly correct mis-prints, and add some results on coverings in the chapter on \( L^p \) function spaces. But I cannot swear to its content the way I can to the 2nd edition.
Stuart Hampshire, Justice Is Conflict
This is a strange (and short) little book of philosophy. The starting point is Plato's analogy, in the Republic, between conflict within the soul and conflict within the city (= polity). Hampshire says that, pace Plato, the way we really resolve conflict in the city is to make sure that all (he says "both") sides know that they have been able to make their case and be heard, even if they cannot get what they want. What ultimately matters is that there was a fair procedure, rather than a substantively just outcome. In the analogy of inner conflict, individual people just have more-or-less incompatible values, and we should not expect to find some way of reconciling them or subordinating one to the most correct values. Nor, he says, should we even want such a reconciliation or ordering.
I am sympathetic --- in some sense he's getting at the core of liberalism --- but I found the argument lacking. The analogy is obviously a bit weak: I don't think he ever really addresses what would correspond to a fair procedure in the soul. (Adversarial or critical thinking is all very well to endorse, but being your own critic has obvious limits.) Also, I think he equivocates about whether unifying values is impossible, or merely undesirable. That's fine by me, because I am strongly in the "impossible" camp --- I encountered "A heterarchy of values determined by the topology of nervous nets" at an impressionable age, and still regard it as irrefutable --- but philosophically a bit unsatisfying.
More frustrating was that Hampshire is fully aware that there are often disputes about which procedures are fair, and this doesn't seem to help us figure that out at all. To use a (banausic and depraved) analogy of my own: if I am writing new code to perform some task, i.e., devising a procedure, I check whether it works right by seeing if it gives the correct answer on test cases, i.e., is substantively correct in particular circumstances. But of course, just to make things circular, in other cases I work out what the answer is by using my procedure. At a much more elevated plane than numerical software, something like this would seem to be at work here, and could use some philosophical illumination. That is, I wish Hampshire would absorb something like Laudan's Science and Values. §
George Malagaris, Biruni [doi:10.1093/oso/9780190124021.001.0001]
Brief historical study of Abu Rayhan Muhammad ibn Ahmad al-Biruni (973 -- 1050?), emphasizing the historical context of Central Asia and the eastern Islamic world in general, giving the main facts of Biruni's biography (including puncturing some picturesque stories), and surveying his major works. Pride of place in Malagris's treatment goes to Biruni's India, fairly enough, but he's pretty comprehensive, and seems to understand the math. (I was astonished to learn that Biruni translated/adapted the Yoga sutras of Patanjali, which must have made some heads explode.) There's also some treatment of his correspondence with ibn Sina; it is simultaneously reassuring and depressing to see that a millennium ago, great scholars were just as capable of mutual incomprehension, dismissal, and pettiness as their modern counterparts, or online posters (cf.) (Actually, I suspect there's the possibility for a very interesting study of different conceptions of "science" in this exchange, and I wonder if someone has done it.) The book concludes with a treatment of Biruni's place in later historical memory, including the way he is claimed by multiple modern nation-states as part of their illustrious past. §
John Scalzi, The Kaiju Preservation Society
Mind candy comic science fiction. It's Scalzi, which means it's funny and mostly but not entirely lightheartedly, and reads extremely smoothly. §
Jane Langton, The Dante Game
Mind candy mystery: the umpteenth book in Langton's series, in which Homer Kelly stumbles his way into an artistic or literary enthusiasm and a homicide investigation. This time it's Dante, and the city of Florence, and the new pope's anti-drug crusade, which is far too successful for some people's liking. It's an old favorite which holds up very well. (Previously.) §

Books to Read While the Algae Grow in Your Fur; Pleasures of Detection, Portraits of Crime; Philosophy; Commit a Social Science; Scientifiction and Fantastica; Islam and Islamic Civilization; Afghanistan and Central Asia; Writing for Antiquity; Mathematics; Teaching: Statistics of Inequality and Discrimination

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

February 28, 2022

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

Attention conservation notice: I have no taste, and no qualifications to opine on the history of Central Asia, the philosophy of science, the anthropology of New Guinea and/or cultural creativity, archaeology, Antarctic exploration, or the philosophy of Spinoza.

Adeeb Khalid, Central Asia: A New History from the Imperial Conquests to the Present
By "central Asia", Khalid means "Turkestan", both the eastern parts conquered by the Qing in the 1700s and the western parts conquered by the Romanovs in the 1800s. (Thus Afghanistan, Tibet, Mongolia, etc., feature only incidentally.) He begins with those conquests, after a little scene-setting to make their events comprehensible, and then goes down to 2020 and the on-going police state and cultural genocide in Xinjiang. Khalid's great (and persuasive) theme is how ordinary this history is, in a global perspective --- imperial conquest, the arrival of modernity, the development of nationalism and the construction of national cultures (he doesn't use the phrase "peasants into Uzbeks", but he comes close), Communism as a vehicle for nationalism, ambitious-to-mad state projects to develop economies, to transform nature and/or transform society, widening entanglement with global culture and economic forces... This is what the 19th, 20th and 21st centuries were like, for much if not most of the world. It's extremely scholarly --- Khalid has clearly read and synthesized almost everything --- but still very readable. If you are at all interested in this part of the world, it's very much worth your time. §
Wesley C. Salmon, with Richard C. Jeffrey and Jeffrey G. Greeno, Statistical Explanation and Statistical Relevance (Pittsburgh: University of Pittsburgh Press, 1971)
1300 words of review: Distinctions That Make Differences to Chances.
Annalee Newitz, Four Lost Cities: A Secret History of the Urban Age
I have mixed feelings about this. On the one hand, it's pleasantly-written and engaging popular social science about four interesting and important cities that were, for one reason or another, abandoned and (largely) forgotten: Çatalhöyük, Pompeii, Angkor and Cahokia. I learned from it, and I mostly enjoyed reading it. On the other hand, I sometimes found myself irritated by the sensation that Newitz was pandering to the prejudices of people like me --- all the cities were full of diverse immigrants, etc., etc. (Looking around after writing that, I see James Palmer had a similar reaction to those bits.)
Beyond those matters of tone, though, I do want to quibble with the way Newitz presents these cities. Many archaeologists have a bad tendency to present speculative interpretations as though they were facts. (They are not, of course, alone in this, and I've complained about this before.) This tendency seems to be very much on display here in the chapters on Çatalhöyük and Cahokia, where we have no writings to fill us in on ideologies and structures of inequality (not to say oppression). I can't help but suspect that this makes those cities better screens for modern projections than Pompeii and Angkor. There's also some trash-talking of V. Gordon Childe that strikes me as unfair, and dismissal of the idea that there are developmental trajectories to more hierarchy, size and complexity as Eurocentric myths, rather than cross-cultural empirical regularities. (And of course a key part of the Enlightenment world-view was seeing Europe as a place which had regressed in these regards for a millennium of barbarism, "mired in the superstitions and brutal monarchies of the Middle Ages", as Newitz puts it on p. 210.)
On re-reading this, I see I've given more space to what irritated me, which is mostly incidental, than to what I enjoyed --- so I will just re-iterate that despite my quibbles, I did enjoy. §
(Thanks to Jan Johnson for my copy of the book.)
Fredrik Barth, Cosmologies in the Making: A Generative Approach to Cultural Variation in Inner New Guinea
750-plus words of review: Cosmology and Cosmologists --- The Modern Ok School.
(I forget what chain of references first put this on my radar --- probably something in the Dan Sperber / Pascal Boyer nexus, but that's honestly just me guessing.)
Edmund Stump, The Roof at the Bottom of the World: Discovering the Transantarctic Mountains
A scientist's winningly enthusiastic history of exploration in the Antarctic mountains, from the first visits to the continent, through the heroic era, to the early 1960s. (It's startling just how much more massive the US's post-1945 efforts were than everything that came before.) The stories are supplemented with Stump's own memories of decades of geologizing on the continent, and his very good photographs. §
Steven Nadler, A Book Forged in Hell: Spinoza's Scandalous Treatise and the Birth of the Secular Age
Partly exposition of the Theological-Political Treatise, partly a biography of Spinoza, partly intellectual, political and religious history to set the context. I enjoyed it, but since I've never actually read the Treatise, despite an interest in Spinoza, I'm in no position to judge it. §

Books to Read While the Algae Grow in Your Fur; Writing for Antiquity; Philosophy Enigmas of Chance; Afghanistan and Central Asia; The Great Transformation; Minds, Brains, and Neurons; Commit a Social Science; Psychoceramics

Posted at February 28, 2022 23:59 | permanent link

January 31, 2022

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

Attention conservation notice: I have no taste, and no qualifications to opine on the history and geopolitical context of Antarctic exploration, the social structure of medieval China, or philosophy of any kind.

Berlin Station
For reasons I will not elaborate on, I binge-watched the entirety of these two spy drama series over a period of about eight weeks. (My viewing-partner needed a lot of distraction, and had lived in both Berlin and London.) Both had ripped-from-the-headline plots and some good acting [*], including some overlapping cast. Over-all, I liked Berlin Station better, since it had more ambitious and more coherent plots, though there was a development late in the third and final season which at last made me get why people write "fix it" fanfic. (Yes, I went looking and found that people had indeed written the relevant fixit fics. Yes, I read them. No, I will not link to them.) There is a dissertation to be written about the absurdity of many of the plots in MI-5 (the economics alone -- oy vey). One nice question to investigate in such a dissertation would be whether those hare-brained notions arise from the writers' sincere ideas about how the world works, the audience's ideas about the world, the writers' ideas of the audience's ideas about the world, or the writers' ideas of what the audience will tolerate in escapist entertainment. §
*: Except for the painful imitations of American accents in MI-5.
Adrian Howkins, Frozen Empires: An Environmental History of the Antarctic Peninsula
A solid history of political conflicts over the Antarctic Peninsula between the British Empire, Argentina, Chile, the US and the Soviet Union, with other parties showing up as bit players. Howkins makes a big deal out of a contrast between the imperial powers' claiming "environmental authority", in the sense of producing universally-valid and useful scientific knowledge about the environment, and the "environmental nationalism" of Argentina and Chile, claiming a more intimate, specific and un-generalizable connection to Antarctica and its environment. (I'd like to read some of the literary works Howkins references, but lack the Spanish.) In this view, the Antarctic Treaty, which suspends sovereignty claims over the continent but limits influence to countries engaged in serious scientific research, constitutes a full, apparently final, victory of environmental authority over environmental nationalism. The actual Antarctic environment and its history is thus not in the foreground. It appears more by way of an obstacle to (e.g.) Chile trying to actually have a naval or administrative presence on the Peninsula, or whaling becoming unimportant.
While I began this very skeptical that there was anything interesting to say about imperialism in the only part of the world where there wasn't anyone to imperialize over, by the end Howkins had me convinced this was, in fact, a real part of the history of Antarctica. (That Argentine and Chilean nationalists were an alternative to imperial environmental authority, as opposed to just wanting to be the authoritative imperialists themselves --- there I was less persuaded.) §
Nicolas Tackett, The Destruction of the Medieval Chinese Aristocracy
This is awesome: it's a social network study of office-holding elite of the later Tang dynasty (after the An Lushan rebellion*), based on funerary inscriptions that gave extensive biographical and genealogical details. Archaeologists have dug up thousands of these, along with others recorded by epigraphers; in some cases these can be connected to biographies in the official dynastic histories (and the two sources usually agree). By assembling a database of these inscriptions, Tackett is able to, in turn, construct a social network of the Tang elite --- rich families that held high office, for many generations on end, in many cases over multiple dynasties. Tackett documents their persistence in office, their peregrinations around the empire, their residences in or between the two capital cities of Chang-an and Luoyang, and their intermarriages and ties of patronage. (Interestingly, the marriage network seems to show two modules or blocks**, one centered on the imperial family. I would have expected more; this would be worth investigating with good community-discovery methods.)
Tackett's argument, convincing to this non-expert, is that this elite was incredibly successful at maintaining their position, despite all the challenges put in their way --- not just An Lushan, but the rise of more-or-less recognized hereditary warlords in the northeast, and the examination system. (My fellow Eisensteinians will perk up when Tackett discusses the role of family manuscript libraries in preparing for competitive examinations in a pre-print society.) In this account, this elite was perfectly set to continue perpetuating itself for generations to come, until the Huang Chao rebellion captured and wrecked the capital cities in 880--881, and in doing so just flat-out killed an immense proportion of those elites. This was the destruction of the title, and more or less the close of Tackett's story.
Now obviously I am not any kind of expert on medieval China, and so it would be presumptuous of me to judge whether Tackett has fairly encompassed all the relevant evidence, and so render a judgment on his account of both the continued pre-eminence of this elite, and its extinction. But it makes a great deal of sense, and I really want to get my hands on the data. I'd recommend it for anyone interested in historical social networks, especially recovering social networks from text, at least if they have basic familiarity with the outlines of pre-modern Chinese history. §
*: While it's tangential to his point, Tackett cannot resist pointing out that Steven Pinker, in describing the An Lushan rebellion as proportionally the worst disaster in human history, relied on a source which obviously confused a decline in the Tang state's ability to enumerate (and so tax and conscript) its subjects with an actual death toll.
**: Tackett says "cliques", but clearly doesn't mean the word in its graph-theoretic sense.
Ernest Gellner, The Devil in Modern Philosophy
1974 essay collection by one of my gurus; I first read it in 1997 when I'd just discovered Gellner and was tearing through everything of his I could find, and re-read it now because the CMU library got electronic access. The essays here range in time from the 1950s, when Gellner was attacking Wittgenstein and "ordinary language" philosophy, through the early 1970s. So the oldest layer here consists of companion pieces to Words and Things, while the most recent are studies for Legitimation of Belief. On re-reading, what I found the most interesting was that top-most layer. I would particularly single out the study of French 18th century materialism, as exemplified by d'Holbach's System of Nature, and the final essay "On Chomsky". Gellner's point in the latter is that what made Chomsky truly revolutionary was his insistence that ordinary human "lifeworld" competences require explanation, and that real explanations must be impersonal, mechanistic, structural. In Gellner's rendition, Chomsky's real objection to behaviorism wasn't that it was inhuman, but that only pretended to give mechanistic explanations. (I think this is right.)
I can't recommend this to anyone who isn't already deeply into Gellner, but I do want to take the occasion to plug Legitimation of Belief, which is terrific. §
Susanna Clarke, Piranesi
This is radically different from Jonathan Strange and Mr. Norrell, but still amazing. Having carefully preserved myself from spoilers, there were only one or two points where I could see what was coming before the narrator did, and that was, for me, part of the charm, so I will keep my mouth shut about the marvelous transformations you will experience as you read this. You should read this. §

Books to Read While the Algae Grow in Your Fur; Writing for Antiquity; Networks; Scientifiction and Fantastica; Philosophy

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

December 31, 2021

Books to Read While the Algae Grow in Your Fur, December 2021

Attention conservation notice: I have no taste, and no qualifications to opine on the fountainheads of the western philosophical tradition, the history of 17th century science, political philosophy, cognitive psychology, the transmission of inequality, or even social-scientific measurement.

Plato, trans. and ed. Christopher Rowe, Theaetetus and Sophist
Theaeatetus is about knowledge, and more specifically how false belief is even possible --- say, falsely identifying someone else as Socrates, if we (supposedly) know Socrates. It's notable for Socrates propounding at least three distinct theories of knowledge, and undermining them all, ending in perplexity. There are some deeply interesting pieces here, including bits (like the analogies of the wax impressions, and of the aviary) where Plato is trying to think through how to make something knowledge-like work. Then there are the bits of metaphysics about being and not being which I frankly cannot comprehend, and have to hope sounded more plausible in Greek. (I do not think this is Rowe's fault.)
(The dialogue is also notable that early on Socrates makes a big song and dance about how he's just a "midwife" and is only going to help bring out the ideas already in young Theaetetus's mind. Then the whole rest of the dialogue is Socrates setting up and knocking down theories, with one piece of criticism from Theaetetus's teacher Theodorus [161]; the youth contributes exactly nothing, beyond the usual "just as you say, Socrates" or "I do not altogether follow, Socrates". [See also.])
Sophist is, supposedly, a sequel, where Theatetus converses with another distinguished visitor, an unnamed philosopher from Elea. (Socrates has vanished.) The goal here is to try to define the character of the sophist, by means of a series of binary distinctions. The visitor propounds a series of very distinct-looking definitions, all unflattering, which are held to be equivalent. To give something of the flavor, one definition (223) is
Then according to what we are saying now, Theaetetus, it seems that if we take expertise in appropriation, in hunting, in animal-hunting, in land-animal-hunting, in the hunting of humans, by persuasion, in private, involving selling for hard cash, offering a seeming education, the part of it that hunts rich and reputable young men is --- to go by what we are saying now --- what we should call the expertise of the sophist.
while another (268) is
The expert in imitation, then, belonging to the contradiction-producing half of the dissembling part of belief-based expertise, the word-conjuring part of the apparition-making kind from image-making, a human sort of production marked off from its divine counterpart --- if someone says that the one who is 'of this family kind, of this blood' is the real sophist, it seems his account will be the truest.
In between, there is a lot of discussion of, essentially, how multiple statements can all be true of the same object.
(Theaetetus opens with a frame-story about someone having witnessed, and taken notes on, the original conversation between Theaetetus, Socrates and Theodorus, and ordering his slave to read the dialogue that follows. This conceit is forgotten in Sophist.)
I am impressed with Theaetetus (though not with Theaetetus), but both books are strange, and left me feeling I'd missed the point. §
Mary Sisson, Tribulations
Mind candy science fiction, sequel to Trang and Trust. It's deeply enjoyable and I hope we don't have to wait another seven years for more. §
Lois McMaster Bujold, Penric and the Shaman, Penric's Mission, Mira's Last Dance, The Prisoner of Limnos, The Orphans of Raspay, The Physicians of Vilnoc, The Assassins of Thasalon, Knot of Shadows
Mind candy fantasy, following on from Penric's Demon but all, I think, self-contained. These are short, minor Bujolds (except for Assassins, which is a full-length novel), but even minor Bujold is a treat. (No purchase link since these only seem available electronically.) §
Domenico Bertoloni Meli, Mechanism: A Visual, Lexical, and Conceptual History
This is a brief but deeply erudite historical study of what "mechanism", "the mechanical philosophy" and mechanical explanations meant during the long 17th century that gave us the Scientific Revolution. Bertoloni Meli has read, seemingly, absolutely everything, in multiple languages, and can move skillfully and insightfully from historiographic debates about "the mechanization of the world picture" to contemporary ideas in the philosophy of science about explanation by mechanisms to the details of how ligature of arteries were drawn in anatomical texts, and what this tells us about how doctors' understanding of what ligatures did changed. All of this is done with very graceful writing and elegantly-chosen illustrations. It's incredibly impressive and makes me want to read a lot more of his work. §
(On a local and merely personal note, this book is based on lectures given at the University of Pittsburgh in 2016. I was told about those lectures and invited to attend them by a then-new acquaintance who worked in the history of science. Only in retrospect did I get why she seemed so disappointed when I had to cancel on short notice. I am not very swift on the uptake, but --- Reader, I married her.)
Joseph Heath, Enlightenment 2.0: Restoring Sanity to Our Politics, Our Economy, and Our Lives
2800 word review: Enlightenment Is Other People. §
Patrick Sharkey, Stuck in Place: Urban Neighborhoods and the End of Progress toward Racial Equality
Sharkey's primary emprical finding is that, among all black families, there is a substantial minority of very poor black families living from generation to generation in neighborhoods with many other poor black families, and who mostly move (if they move at all) from one such neighborhood to another. Moreover, these families are really much worse off than typical Americans, in every way which we can measure, and which drags down over-all averages for blacks as a group. What Sharkey wants to argue, on this basis, is that part of the reason for these persistently bad outcomes is that concentrating these poor, troubled families in neighborhoods with a lots of other poor, troubled families makes it harder for any of them to improve their situation.
The natural methodological worry goes like so: suppose that there are some poor, troubled families who will struggled to improve their situation, partly because of internal issues, partly because of larger social forces which would afflict them wherever they lived. But because they are poor and troubled, all sorts of processes, starting with housing costs, will concentrate them in neighborhoods with other families in similar situations. Even if the neighborhood has no effect on life prospects, it would still be a sign of those prospects. Under mild assumptions, it'd be a stronger sign the longer a family has been stuck in such a place. More plausibly: regressions of life outcomes on neighborhood of residence, neighborhood of origin, parents' or grant-parents' neighborhoods, etc., could all be explained through infinitely many combinations of genuine neighborhood effects, and neighborhoods acting as signs.
Now there are ways you can begin to pick apart this causal-inference tangle, and in various of the journal papers on which this book is based Sharkey does so. (Some, but not all, of this material is covered in the online appendix.) In particular, his joint paper with Felix Elwert on the inheritance of dis-advantage is actually just as good as I'd expect of Felix. But in this book I grew impatient, while reading, with the feeling that I was just being told about every possible linear regression which you could run on the Panel Study of Income Dynamics where both race and neighborhood poverty rate were regressors, as though that addressed the issue. I realize that this says more about my professional deformations than the merits of this book.
I read this for the inequality class, and while I didn't assign any of it this time, I might well do so if I re-teach it. I will definitely be recommending the backing papers as supplemental reading. §
Richard A. Zeller and Edward G. Carmines, Measurement in the Social Sciences: The Link between Theory and Data (1980)
I wish I liked this more, because it's heart is in the right place. In particular, trying to see what remains of psychometric's classical test theory after admitting that systematic error is possible is a worthwhile undertaking! But this book's faith in what can be achieved through factor analysis and comparing correlation coefficients is utterly misguided. (Cf., though Clark doesn't discuss this book explicitly, Glymour.) I had hoped I could recommend this to The Kids, but an adequate exposition of necessary caveats would rival the text itself for length. §

Scientifiction and Fantastica; Enigmas of Chance; Writing for Antiquity; Philosophy; Commit a Social Science; The Dismal Science; The Beloved Republic; Teaching: Statistics of Inequality and Discrimination; The Progressive Forces; Minds, Brains, and Neurons; The Collective Use and Evolution of Concepts; The Continuing Crises The Great Transformation

Posted at December 31, 2021 23:59 | permanent link

November 30, 2021

Books to Read While the Algae Grow in Your Fur, November 2021

Attention conservation notice: I have no taste, and no qualifications to opine about how to conduct either social science, or the German Social Democratic Party at the end of the 19th century.

Eduard Bernstein, The Preconditions of Socialism (1899; trans. and ed. Henry Tudor)
The original revisionist. Here are some of Bernstein's more important and representative heresies, from the viewpoint of orthodox, Second International Marxism: the dialectic is unhelpful and not actually essential to Marx and Engels's best work; the number of people who own capital is growing, not shrinking; class structure is not simplifying to a stark opposition of capitalists and proletarians; workers are not being increasingly immiserated; formal democracy is essential; it turns out that in even partially-democratic states, organized political action can do a lot to improve worker's lives, without waiting for the revolution; the state couldn't just take over running the economy successfully; etc., etc. As should be obvious from my tone, I find a lot of these ideas extremely congenial, though Bernstein was, it must be said, rather more sanguine about colonialism, and especially about European nationalism, than looks wise in retrospect. (Since, 15 years after this book, he was opposing World War I in the Reichstag, I wonder if he ever explicitly admitted errors on those points.) A dedicated proponent of orthodoxy could, naturally, argue that while the prophecies haven't been fulfilled yet, their hour will come round at last...
This edition is the first un-abridged English translation, with helpful footnotes explaining now-dated references, and giving full citations for his quotations &c. (The first, seriously abridged, English translation is online.) It says something about me that I found this an exciting read.
Scott Ashworth, Christopher R. Berry and Ethan Bueno de Mesquita, Theory and Credibility: Integrating Theoretical and Empirical Social Science
My remarks having passed the 900 word mark, they became a separate review.
C. J. Cherryh, The Paladin
Mind-candy fantasy, in a world of little magic, but a lot of superstition and a lot of desire for vengeance. Not Cherryh's identity-bending best, but I wanted a comfort re-read and this delivered.
Candice Fox, Hades
Mind candy thriller. What if (I refuse to regard this as a spoiler) Dexter, but the serial killer who hunts killers was a Sydney homicide detective? (I haven't bothered to go check the publication dates to see if that actually explains it, or it's just convergent evolution in the space of psycho-killer mysteries.) OK but left me without any desire to continue the series.
Lee Goldberg, Gated Prey
Extremely fluffy mind-candy mystery. (Previously.)

Books to Read While the Algae Grow in Your Fur; Pleasures of Detection, Portraits of Crime; Commit a Social Science; Constant Conjunction Necessary Connexion; The Progressive Forces

Posted at November 30, 2021 23:59 | permanent link

November 23, 2021

Call to Pittsburgh (2021 edition)

Attention conservation notice: An academic job ad.

We are looking to hire this year, both on the teaching track and the tenure track. It's a great department and you should apply if you're at all interested in professing statistics, even or indeed especially if your background isn't traditional stats. (I say this despite the fact that every application we get now means more work for me later.) If any reader has questions I might be able to answer, please don't hesitate to get in touch.

Kith and Kin

Posted at November 23, 2021 11:00 | permanent link

Three-Toed Sloth