23 September 2016

Amerika bira - 2016

Bliže se debate predsedničkih kandidata, prva je u ponedeljak. Klinton i dalje ima solidnu prednost u ukupnom broju glasova, ali u swing states Tramp ima odličan trend. Kada bi se izbori održali danas (uz uvažavanje nesavršenosti merenja kada je razlika u domenu dve statističke greške) Tramp bi imao samo 6 elektorskih glasova manje od Klinton, to jest Trampu bi nedostajala   jedna država. To je fundamentalni preokret u odnosu na situaciju od pre mesec dana. Takođe, novo je što imamo zaista jakog trećeg kandidata, Džonsona, ispred Libertarijanske partije, koji može u idealnom slučaju dobiti i dvocifren procenat na izborima, ali bez nade u dobijanje elektora.

Kada je reč o Senatu nakon stabilnih izgleda da republikanci zadrže većinu, došlo je do poravnanja u anketama, a potom do blage prednosti republikanaca 51:49. Republikanci bez problema zadržavaju Predstavnički dom, iako će demokrate verovatno  imati više glasova na nacionalnom nivou.

Sve u svemu, čekaju nas interesantne debate, a ja ću, kao i uvek, izaći da dubljim analizama pred same izbore, nakon sučeljavanja kandidata.

Do tada ispod su linkovi o američkom izbornom sistemu.

O izbornom sistemu - izbor predsednika

O izbornom sistemu - Kongres

13 September 2016

Kritika kritike Kanemana, 2. deo

What is obscure? „At most, they simply demonstrate either the subjects’ ignorance of certain obscure statistics“ (p. 132) Well, ignorance may indeed be a relative term, but it is hard to construe the huge numerical preponderance of farmers over librarians as „obscure“ for anybody not living in a cave. In non-Orwellian speak, “certain obscure statistics” applies to things like the number of cane toads in Australia or the famous example of Enrico Fermi, the population of piano-tuners in Chicago. “Did it occur to you that there are more than male farmers for each male librarian in the United States?”—as if this information is intuitive or self-evident.“ (p. 134) it certainly is not self-evident, but contra BT it is intuitive, since intuition is based (on most reasonable philosophical construals, e.g., Hume’s “striking resemblance” in A Treatise of Human Nature) on actually having some prior knowledge on relationship of empirical objects. Of course, BT are free to use their own definition of what is intuitive or not – but are hardly entitled to criticize Kahneman for not sticking to their private definition in this respect.

„When respondents perform poorly, the reader is led to interpret their failure as a cognitive bias, although simple ignorance of either quantitative technique or of relevant facts suffices to explain it.“ (p. 134) Alternative explanations – which are, interestingly enough, not entertained by BT – include low IQ, iodine deficiency, serious depression, or simple laziness.

On bats and balls: “This is not at all a simple puzzle. The fact that it involves bats, balls, and small amounts of money makes it look simple and thus lulls respondents into thinking they should have the answer ready. In reality, this is a system of two equations with two unknowns—the type of mathematical problem that, in the United States, is not learned until at least the eighth grade, if ever.“ (p. 135)

Now, an interesting issue is why should the US education system (a broken one, btw, according to authors so disparate as Alan Bloom, Francis Fukuyama, Judith Butler, or Bernie Sanders) be a norm here? Even more interesting is how in the world could a person buying chocolate in two different packages in two shops for a fixed amount of money establish whether she received correct change at the counters or one shop is indeed cheaper than the other? This is also a system of two equations with two unknowns. And a person incapable of deciding so might not be irrational in the narrow sense of BT, but in reality should not be trusted very much. There are countless examples of similar problems involving two equations with two unknowns appearing in everyday contexts. Some adults take some kids to a movie, five people in all. The cost for adults is $9 and the cost for kids is $6. They paid a total of $36. How many kids are there?

„[T]he question is not only outside our normal range of experience and therefore irrelevant to the lives of most people.“ (p. 135) Only those people not doing shopping – or those not very careful with their money, or those not likely to go with kids to a movie, or... On a serious note, this assertion that what is outside our own range of experience is therefore irrelevant to our lives or to the lives of most people is, at best, outright bizarre. As someone who did some work in risk analysis, I find this claim preposterous. Rational people take into account events outside their own range of experience all the time – the insurance industry would not exist otherwise. Our own death is by definition outside our range of experience (alleged after-death experiences or spiritism notwithstanding) and yet people invest in life insurance all the time. Large natural catastrophes like tsunamies, large earthquakes, supervolcanic eruptions, etc. are outside of range of experience of most people – and yet are supremely relevant for anyone on the planet. Nuclear war has been, fortunately, outside our own range of experience so far – and yet is utterly relevant for all lives on the planet, human and animal and plant alike. In claiming this, BT show surprising narrow-mindedness and – yes, ironically, considering their parable above – large degree of self-absorption.

On geography: „There really should be no surprise that a subject asked about the total number of murders in Michigan is not able to invoke two different pieces of information never mentioned in the question: that Detroit is a high-crime city and that Detroit is in Michigan.“ (p. 135)

Consider a related statement: There really should be no surprise that a voter asked about the promise of a candidate for the governor of Michigan to reduce the number of murders in Detroit is not able to invoke two different pieces of information never mentioned in the question: that Detroit is a high-crime city and that Detroit is in Michigan. Plus, the voter was never explicitly told that reduction in the number of murders is desirable, therefore she cannot make rational judgement on the candidate’s program. And yet, and yet, the voter will be – irrationally? – asked to make a judgement on those issues at the time of elections.

The example in footnote 3 is even worse, since it is unintelligible: if drivers believe that they are better than the average and the average is being construed as “unexceptional”, what in the world could it mean for someone to be “better than unexceptional”? One could similarly argue that he is “fitter than yellow” or “more intelligent than mountainous”; it could mean something only in the context of a Derridian or a Žižekian farrago of nonsense.

„A student who cannot solve the integral because he did not think of making the particular substitution in that case is not sufficiently proficient at calculus; but he is not biased against solving the integral.“ (pp. 135-136) Such conclusion would require telepathic superpowers to be established. In most cases, bias is defined in science as something discernible from an external perspective (perspective of observer or a statistician) – e.g., Malmquist bias, Signor-Lipps effect, various anthropic biases, etc. So, while we might indeed refrain from calling the student’s lack of performance a bias without further information, it is at least conceivable that it results from a bias, e.g., from an error in his textbook on the particular substitution, or from the teacher lacking skills in this respects, etc.

„Respondents may be wrong about the total number of murders in Detroit and Michigan, but these aggregate numbers are information that is of very little importance outside government statistical offices, just as is the question Kahneman asks.“ (p. 136) Unless one is living in Detroit or in rural Michigan or considers moving there or should judge programs of crime reduction or is deciding upon donating to charities in Michigan or some of other zillion cases BT – similarly as with the application of conservation of momentum and energy in driving – conveniently downplay and/or ignore. Which in their case, I submit, is not caused by ignorance, but by the biased view of the role of knowledge in human actions and values. However, BT do not fail to emphasize that it is outside government statistical offices, and not statistical offices or, say, private charity research like GiveWell or other private-sector statisticians, who do no less statistical research than the government does.

On the Linda experiment: „A reasonable person may, in effect, be answering a different and broader question that evaluates the entire situation rather than the textual question alone—for instance, “What has the examiner designated as the correct answer?” Or “What is the most likely answer in this experiment that I am in?”“ (p. 137)

I imagine one should use similar heuristics in filling one’s tax forms for example – not giving narrow and literal answers, but musing on what the government really wishes to achieve with existing tax rates or whether it would be better for all parties if I answer something differently, etc. The outcome of such an experiment would certainly be wondrous! Again, it is pretty ironic that BT ascribe such highly intelligent analysis to the very same set of subjects who are previously excused for failing to understand logical conjunction or for not knowing that Detroit is in Michigan.

On choices allegedly beyond cognitive biases: „it may be worth contrasting them against the costs of mistakes that clearly have nothing to do with cognitive biases: the cost of choosing a profession one ends up hating, the cost of not finding a suitable mate, the cost of having children too early in life or too late, the cost of moving to a place one ends up disliking, the cost of adopting a pet or sending children to a private school, and so on.“ (p. 140) How in the world are those choices not influenced by cognitive biases? After all, one decides about school for one’s children often on the basis of pure confirmation bias, and the profession one ends up hating is intuitively (if not self-evidently!) often a consequence of the temporal horizon bias, etc.

„Kahneman’s reliance on this model of decision making suggests that we would ideally become more literal, abstract, out-of-context thinkers and, as such, more in line with the neoclassical economic model, without making it clear how this would improve the human condition.“ (p. 142) The charge is as bizarre as what was brought, for instance, against Einstein by „Aryan physicists“ Lenard and Stark in 1930s that the theory of relativity does not contribute to the glory of Aryan race or obtaining the desired Lebensraum. On the Serbian scene, we have witnessed a dumb science minister (Dragan Domazet) who urged scientists to work „for their country instead of working for libraries“ (!). This misplaced pragmatism – reminiscent of Lysenkoism in Soviet times – has never been a signpost of scientific success.

On Kahneman’s alleged revolution: „In behavioral economics, then, we do not find the building blocks of an alternative decision making theory that could be incorporated into a more fruitful type of social science. In Kuhnian terms, it is not a scientific revolution but a strange transmogrification of an old and manifestly inadequate paradigm.“ (p. 143) While „Kuhnian terms“ should make one suspicious, it is the idea that we should consciously strive toward „fruitfulness“ of science – even social one! – which is really problematic. Arguably, Kuhnian view of revolutions in science is much less important for epistemology and philosophy of science of today than the Lakatosian notion of research programmes – and it is exactly Kahneman’s research programme (and certainly not a revolution!) which brought him the deserved success. Even under Kuhnian terms revolutions are not acts of will, as BT seem to suggest in both the title and this concluding passage – there is no perceived desire for a more fruitful kind of science which leads to a scientific revolution. In fact, the Kuhnian account does no good to BT’s concerns exactly because Kuhn insisted on incommensurability of paradigms, so there could be no way to say that a new paradigm is more or less fruitful, adequate or inadequate. Instead, as Kahneman is well aware, only a gradual competition of research programmes and reforms following their improvement lead to truly improved insight into problem situations. Kahneman is no revolutionary – and he’s among the greatest for exactly this reason

12 September 2016

Kritika kritike Kanemana, 1. deo

Slaviša je ovde ukratko predstavio svoju (i Željkinu) kritiku Kanemanove knjige i celine njegovog programa. Pre svega da naglasim da je sjajno što je taj tekst objavljen, da su autori tom studijom ostvarili po svakom kriterijumu odličan naučni rezultat, da je bez ikakve sumnje hrabro kritikovati takvu veliku metu – i da im na radu iskreno čestitam. Rad je vrhunski i svako zainteresovan za teme sa ovog bloga bi dobro učinio da ga pročita. Ovde kačim svoju kritiku njihove kritike, nastalu od beležaka na marginama tokom čitanja njihovog rada. Nije poenta odbrana Kanemana – kome to svakako nije neophodno! – nego otvorena i oštra intelektualna debata o nekim od tema koje jesu i teorijski i praktično zanimljive.  
Tekst je na engleskom, iz tri razloga: (i) zato što iscrpno citira delove studije Buturović & Tasić, pa bi bilo rogobatno prebacivati svako malo sa srpskog na engleski i obratno; (ii) da bismo izbegli terminološke zađevice oko “najadekvatnijeg” prevoda nekih od korišćenih termina; (iii) iz praktičnog razloga što su i moje beleške na marginama bile na engleskom. Napisan je u relativno opuštenom stilu, bez navođenja referenci, fusnota i ostalih akademskih parafernalija. Zbog ukupne dužine podelio sam ga u dva dela.

Reform vs. counter-revolution: On Buturovic’s and Tasic’s criticism of Kahneman
Buturovic and Tasic (2015; henceforth BT) criticize Daniel Kahneman and the entire project of behavioural economy for taking too narrow concept of rationality, but also for many other perceived errors and insufficiencies. This leads into calling his work a “failed revolution”. Except for a bit of revolutionary zeal (more on that below), it is not quite clear what exactly would BT prefer from any project in behavioural economy. Kahneman’s programme is no good? Fine and well, but it’s not as if there is a glut of alternatives around. And certainly it's not as if BT criticism is, ahem, entirely rational. 
On what counts as advance: “But it does not advance our understanding of human psychology except inasmuch as one otherwise would  have been inclined to believe that people are everywhere and always “rational” in the peculiar sense in which this term is used by economists” (p. 129)
Well, how about the following hypothetical comment on Einstein's relativity: But it does not advance our understanding of physics except inasmuch as one otherwise would have been inclined to believe that physical objects are everywhere and always characterized by absolute space and time in the peculiar sense in which these terms are used by Newton and his followers. One can use this deflationary manoeuvre with equal success against each and every innovator and reformist. But the argument is rather lightweight when we reign in our revolutionary expectations and consider what is realistic to achieve in science. 

On skills and studying rationality: “One recurring issue that has cropped up since Kahneman and Tversky’s early studies of cognition has been their assumption that specific knowledge or skills are essential to rationality. Thus, the possession of statistical or factual knowledge or the use of abstract reasoning has often been uncritically taken as a standard against which we are to judge the answers that participants in the experiments give. This has attracted the critical notice of specialists but not that of the wider world.” (p. 129, emphasis MMĆ)

It is easy to show that “their assumption” can, in fact, be attributed to that slightly earlier fellow, Socrates of Athens, who – most famously in Plato’s Meno and Protagoras – argued that rational definitions of virtue must be “tethered” by knowledge, and therefore it is reasonable to conclude that the virtue can be taught to others (via specific knowledge). His famous dictum about unexamined life not worth living (ὁ ἀνεξέταστος βίος οὐ βιωτὸς ἀνθρώπῳ; Apology 38a) is usually interpreted in the same manner. This has been repeated countless times in the course of Western intellectual history. Whatever intrinsic merits or demerits of the assumption, it is ahistoric and naive (to say the least) to attribute it to Kahneman and Tversky as a sort of newfangled behavioural fad. BTW, how do BT know that a particular standard related to a particular experiment has been accepted uncritically – as contrasted with the situation in which such standard were accepted after much reflection, deliberation, hand-wringing, and going to-and-fro? What is factual evidence for uncritical acceptance of such standards? If there is some such evidence, BT fail to provide it.

Besides, what exactly is the alternative to this millennia-old assumption? That rationality could be (non-circularly) defined without reference to any particular knowledge or skills? It would be interesting to see results of such an enterprise. In any case, the burden of proof lies on BT, and not on Kahneman or anyone else who accepts that particular forms and amounts of knowledge or skills are necessary for any operational concept of rationality.

A long debate – more than a century – in evolutionary biology on the subject of extinction of species ended in conclusion that it is illegitimate to cite inferiority of a species or a higher taxon as the cause for extinction without listing which characters in what context were inferior to analogous characters in surviving taxons. Before we reached that stage, gradualist (il)logic filled textbooks with statements like “dinosaurs went extinct and mammals survived because dinosaurs were inferior”; which, of course, was not empirically supported whatsoever and in the end got reduced to “they had to be inferior in some unspecified way, since they went extinct”. Evolutionary biology and paleontology flourished greatly after getting rid of such nonsense. And there are many similar examples in other areas.

Finally, what exactly should this attention and critical notice “of the wider world”, so lacking in the reception of Kahneman’s work, consist of? Should Kahneman complain that he hasn’t been a guest of The Kardashians yet? Is his work less valuable due to the fact that he has 6,966 twitter followers, in comparison to N zillions of Justin Bieber? In my view the very concept of the “critical notice... of the wider world” is oxymoronic, since critical notice is not something established by a show of hands or a plebiscite, and almost by definition “the wider world” is too heterogeneous for any non-trivial critical notice. And the oxymoron is only strengthened – in a surreal kind of way – if we accept BT’s implication that empirical knowledge or reasoning skills are not truly necessary for demonstration of rationality; BT seemingly expect the same “wider world” which they excuse for lacking knowledge and reasoning skills to offer (presuming rational) criticism of Kahneman. Tall order, if anything.

On the language analogy: „We use language for a purpose, and grammar is an integral part of language.“ (p. 129) So it is natural to expect an intuitive and automatic access to grammar. What is wrong with this statement is clearly seen from an analogous statement, for example: We use mathematics for a purpose, and complex analysis is an integral part of mathematics. Therefore, intuitive and automatic access to complex analysis should not surprise us. Of course, that is absurd. Perhaps a two or three greatest geniuses in mathematics, persons born once per century, could conceivably have intuitive access to complex analysis, but that certainly does not apply to millions (or indeed billions) of users of mathematics. And BT have neither demonstrated that, conversely, the lack of grammar skills characterizing billions of people demand explanation, not have they shown any evidence that their preference for linguistic over mathematical skills reflects anything else then their own personal preference.

This conclusion is strengthened by their continuation and generalization of the same theme: „Statistics, on the other hand, is a body of knowledge created, systematized, and formalized by statisticians.“ (p. 130) I find this simply untrue. Like any other mathematical discipline, statistics is a set of proposition whose validity is given quite independently of statisticians and its statements would be entirely valid if suddenly all statisticians in the world were to die tomorrow or even if there were no statisticians whatsoever. Unless one is an extreme postmodern social constructivist, the statement that, for instance, any probability distribution on the set of real numbers R has at least one median will be true anywhere and at any time, even in the universes with no life and therefore no statisticians. (Of course, standard definitions of terms such as probability distribution or median is assumed.)

„Stating that people are good or bad at statistical reasoning tells us something about their knowledge of and talent for this particular skill and not much else.“ (p. 130) So, how exactly does this differ from claiming that stating that people are good or bad at grammar tells us something about their knowledge of and talent for this particular language skill and not much else? I do not see much of a difference; on the contrary, to paraphrase the authors, statements like these tell us something about their personal ordering of preferences and not much else.

The parable of a physicist: „A passionate physicist without much interest in the outside world could observe that people are very good at manipulating objects but embarrassingly inept at solving problems in theoretical mechanics. Few of us would treat such a statement as evidence that people should gain more knowledge of theoretical mechanics or that they are irrational when they get questions about the subject wrong. We would, instead, conclude that this physicist is making an oddly self-absorbed comparison between knowledge of physics and the ability to operate in the physical world.“ (p. 130)

This is either false or misleading on so many different levels that it is difficult to decide where to begin. For starters, the parable misses the entire envisioned goal: if the goal is set to make people better at manipulating objects, one is entirely entitled to argue that increased knowledge of theoretical mechanics might well help. Which has, by the way, been accepted long ago in sports academies around the world, whose curricula contra BT contain important elements from theoretical mechanics. If the goal of decision theory is to help make better decisions, the analogy holds. Second, in the course of a single paragraph, BT make leap from descriptive to prescriptive stance and back, while pretending to offer a parable from a neutral point of view. Third, if something is “embarrassing”, then clearly there is an opportunity cost to remove the embarrassment by – what a surprise! – gaining more knowledge of the subject, be it theoretical mechanics or Sinhalese syntax or whatever.

The irony is particularly rich when one takes into account that it comes from the same authors who subsequently take Kahneman to task for allegedly providing misleading cues in Linda and other psychological experiments. The number of misleading cues in this passage sets the record for packing density. What else could be the role of such strings of words as „without much interest in the outside world“ or „embarrassingly inept“ or „few of us would treat“ (rhetorical device known since at least Cicero and abused by perhaps every single politician on the planet) or „oddly self-absorbed“ if not providing misleading cues for the reader? „Oddly self-absorbed“ in contrast to – what exactly? Perhaps „commonly self-absorbed“ manner permeating comparisons made by social scientists? (Merriam-Webster offers „common“ as the first-choice antonym to „odd“.) Why is it important that the physicist is „passionate“ and not some boring old bureaucrat? Obviously, framing matters, as Kahneman and Tversky knew and BT confirm (p. 134).

„Statistical skills, unlike physical ones, could be somewhat useful in an ordinary person’s everyday life.“ (p. 130) The logical implication here is that physical skills could not be somewhat useful in an ordinary person’s everyday life, and such general statement is easily disproved by citing even a single counterexample in which physical skills could – and indeed are – very useful in an ordinary person’s everyday life. Such example is, for instance, driving – we have not evolved to drive cars, we do have big problems in properly accounting for conservation of momentum and energy in driving, and there is every indication – since there is no actual research done on this issue – that knowledge of theoretical mechanics is useful in driving (it is used, for instance, in instructions for defensive driving, of course in a simplified form). The example is not mine, it was suggested long ago by Richard Feynman, who was called many things but never “self-absorbed”.

A charitable interpretation of this is that the authors tried to say that the probability measure of cases in which physical skills are important is much smaller than the analogous probability measure for statistics, but such framing would (a) be less flashy, and (b) require at least hinting at some metric at which their personal intuitions about relative usefulness could be justified. But if they wished to convey that meaning, they should have chosen their words more carefully, especially since the context is set by their relentless revolutionary criticism (more on this below) of framings and contexts and backgrounds provided by behavioural economists and decision theorists. For all they who take the sword, etc.

The argument from billions: “But how useful these skills might be is unclear, as billions of people somehow manage to make their way in the world, decade after decade, despite their complete ignorance of statistics.“ (p. 130) Oh, but how useful reading and writing skills might be is unclear as well, as billions of people somehow manage to make their way in the world, decade after decade, despite their illiteracy – and have done so for many millennia. Unclear, indeed.

“Base rates are not unequivocally given to us as stable and known, and the appropriateness of using or disregarding them in particular situations depends on a host of conditions.” (pp. 131-132) Now, this rhetorical stratagem can again be debunked by comparing it to an analogous statement, for instance: Rules of grammar are not unequivocally given to us as stable and known, and the appropriateness of using or disregarding them in particular situations depends on a host of conditions. Sounds right, doesn’t it? After all, there are billions upon billions of people who hardly regard rules of grammar as “stable and known”. And we are still no closer to understanding what exact difference there is between information encoded in base rates and information encoded in the rules of grammar.

On Tom W.: “Only those few subjects (if any) in the third group who had studied the distribution of graduate students by field would have had reason to put any confidence in their guesswork about the matter.“ (p. 133) Again, let us compare this with a linguistic example. Consider the frequency distribution of letters in a language. While few subjects – if any – in a given group may know that e is the most frequent letter in any representative English text, this does not mean that they are really agnostic or have uniform prior distribution of frequency over the set of letters. It is hardly conceivable that even the most linguistically challenged or even illiterate and low-IQ experimental subject will have doubts whether a is more frequent English letter than q, or will give x the benefit of doubt versus s. Contrary to the implication of BT, normative knowledge is not measured by insight into a given database, but by success rate of inferential processes.

„Subjects asked to provide their “best guesses” about something they have probably never thought about before—the proportion of U.S. graduate students in various fields“ (p. 133) – where subjects are not farmers or soldiers or schoolchildren or pensioners but graduate students themselves, who are moving in the environment of other grad students and are perfectly well aware that the fields and departments are unequal in size and scope, are likely to think much about grad schools, etc. etc. If such knowledge should not be regarded as normative for the given population, what should be, according to the authors? Lack of curiosity? Unreflecting indifference? Low IQ?

“Kahneman and Tversky seem to think it is more rational to use made-up statistics than good heuristics.“ (p. 133) And believing the researcher – in psychological experiments where researchers standardly lie and mislead their subjects (e.g. Asch conformity or even Milgram) – is somehow a good heuristics? What kind of normative knowledge prescribed that? Perhaps the Orwellian stipulation that „ignorance is strength“?