About a month ago, we had an interesting discussion here and on Andrew Gelman's blog regarding Richard Florida's theories about the creative class and urban culture (see here, here and here). It got me thinking about one of Florida's favorite examples, Austin, Texas. These days when people think of the culture of that town, the first name that generally comes to mind is South by Southwest, but it's important to note that SxSW came after Dell.
If you were to have asked people in 1980 (shortly before the town started becoming a tech center) about Austin's culture, I suspect the answers would have focused on two main topics: the first would be the outlaw country scene (contrary to the song, Waylon and Willie actually hung out in Austin. Nobody hung out in Luckenbach); the second would be the then dominant effect of the massive UT campus on the town.
You can get a pretty good idea what people thought of that UT/frat dominated culture, from the Academia Waltz, Berkeley Breathed's first cartoon and something of a proto-Bloom County.
Comments, observations and thoughts from two bloggers on applied statistics, higher education and epidemiology. Joseph is an associate professor. Mark is a professional statistician and former math teacher.
Saturday, March 22, 2014
Friday, March 21, 2014
Question of the day
Roger Farmer:
Clearly, if this is the state of the art, these models could be improved (heck, even an employment change penalty function would do wonders).
Why is this a big deal? Because 90% of the macro seminars I attend, at conferences and universities around the world, still assume that the labor market is an auction where anyone can work as many hours as they want at the going wage. Why do we let our students keep doing this?A model is a tool for better understanding the world. While there may be problems where this particular simplification allows complex estimation, when labor markets (e.g. unemployment) is a major target of inference this simplification seems to remove the most interesting variation (e.g. employment friction and how it makes fast job changes undesirable all around).
Clearly, if this is the state of the art, these models could be improved (heck, even an employment change penalty function would do wonders).
Sometimes, the SAT you read about in the news doesn't look much like the actual SAT
[Unless otherwise noted, 'SAT' refers to the SAT Reasoning Test]
There are real concerns about the SAT. The emphasis on vocabulary can and sometimes does create a problem with cultural bias and the test has a history of being misused, as do most psychometrics. Though it is possible to make too much of these abuses, we should remember that, like the IQ test, people have and in a more subtle fashion, continue to use tests like the SAT to make racist arguments.
But while there are valid arguments for changing, deemphasizing, or even eliminating the SAT, these are not the arguments you will see in the anti-SAT editorials in Esquire or the New York Times. Instead, we get attacks on an SAT test that doesn't actually exist (Though it quite possibly may after David Coleman is finished with his reforms).
Though it has long tried to live down the fact for various reasons, the SAT was designed to be what its original name suggests, a scholastic aptitude test. It was also designed to be largely orthogonal to GPA and other information found in high school transcripts. (you can find a more detailed discussion of this point here and here)
In order to achieve that orthogonality the SAT test to be written in such a way that students have taken more advanced classes do not have an unfair advantage. Partly for that reason, the SAT is perhaps unique among major measures of academic accomplishment in that it has almost no rote memory component other than vocabulary.* (From here on out, I am going to focus primarily on the mathematics section though most of the general comments will apply to the entire test.)
An old professor of mine, Bill Condon, once described the analytic SAT as the toughest ninth grade math test you will ever take. That's an extremely apt way of putting it. All of the mathematical concepts are either common sense or things which a ninth grader should have covered. Almost all of the rules and formulas needed for the test are printed in the front of the booklet.
The trouble with coverage of the SAT and to a slightly lesser extent the ACT is that virtually everyone whom you will find discussing it in the pages of a major newspaper or magazine has intense but old and usually highly unreliable memories of the test. Add to that the generally poor quality of the emotionally-charged education reform debate and the result is an incredibly unproductive discussion.
For a representative example, check out this opinion piece written by Jennifer Finney Boylan for the New York Times, which puts the trauma front and center starting with the first sentence:
High school is a trauma-filled time and its humiliations and disappointments can stay fresh for decades as they obviously have here. They do not, however, often lead to objective or accurate analyses. It may well have seemed unfair at the time to be judged on knowledge of relatively obscure words, but given that vocabulary tracks fairly well with reading ability, it doesn't seem unreasonable to ask a future English major to display an understanding of words like 'loquacious,' 'mordant' or even 'cephalopod.' As for the math section, I assume from the definite article that "the quadratic equation" refers to the quadratic formula. If so, that's an interesting choice because that formula does not appear on the SAT.
The math that does appear on the SAT relies on the following:
properties of numbers;
basic algebraic manipulation;
very basic (junior high level) geometry (with relevant formulas printed on the first page);
simple probability;
reading graphs and tables;
logic and problem-solving.
All of these fall into the good-to-know category for the general population and I'd argue the last is especially valuable for English majors (bad logic makes for bad literary criticism and often bad literature).
Boylan then goes on to complain that the SAT relies too much on memorization and to argue for the superiority of high school GPA as an academic metric. As mentioned before, the rote learning component of the SAT is extraordinarily small, far smaller than the corresponding component for almost every test-based grade a student will receive in junior high and high school.
This oddly self-defeating argument "We should drop the SAT because it's too ____; instead, we should rely more on grades/other tests/whatever (which happen to be more _____ than the SAT)" also features prominently in a less personal but much less coherent piece by Esquire.com news editor Ben Collins. Collins' argument consists of a series of largely arbitrary but highly emotional associations (it's not entirely clear why he makes these connections but he certainly feels strongly about them).
The first and possibly strangest of these associations involves Google.
Keep in mind that these numbers include humanities majors. The graduates that a company like Google are interested would almost all be in the first two bins. Google doesn't talk much about SATs at least in part because they've largely maxed out the metric.
Collins' piece actually gets worse from there.
Where to start...
In some parts of this passage, Collins seems to be talking about some tests other than the SAT such as the PISA exams when addressing China** or VAM-based tests when discussing the effects on learning. If this had led up to a condemnation of tests in general the conflation might be at least internally consistent, but with the paragraph about the importance of keeping score that possibility goes out the window. We have to limit his criticisms, however odd, to the SAT.
The only real specific Collins offers about why the SAT should be singled out for elimination is that the test is old. That's partially true. The test has constantly evolved, driven by some of the best and most sophisticated analytic techniques in the field, but in terms of the test's format and its role in the education system, we've had the current set-up since 1930.
I'd argue that the country has had a pretty good run of innovation since 1930 and while I wouldn't claim that the SAT was a major driver, it would be difficult to argue that it held us back. Collins seems to agree on the first part but he takes a strange turn from there. As best I can make it out, he's arguing that America is the most innovative country in the world so it's essential that we drop a major, longstanding component of our education system or we'll become like China.
All snark aside, we probably should have a good debate about the way college admissions work and about the (I think misplaced) emphasis we have come to put on getting into the 'right' schools. Unfortunately, writers like Boylan and Collins aren't contributing to that debate; they're just supplying misplaced anger and emotional baggage.
*There's a big question (too big to address here) about the role of vocabulary in the SAT. Ideally there should be no rote learning element here at all. The vocabulary component is supposed to measure things like how reading volume and comprehension. Memorizing lists of words is, in a sense, cheating; it's also of questionable effectiveness compared to good, active reading habits.
** From China Daily:
There are real concerns about the SAT. The emphasis on vocabulary can and sometimes does create a problem with cultural bias and the test has a history of being misused, as do most psychometrics. Though it is possible to make too much of these abuses, we should remember that, like the IQ test, people have and in a more subtle fashion, continue to use tests like the SAT to make racist arguments.
But while there are valid arguments for changing, deemphasizing, or even eliminating the SAT, these are not the arguments you will see in the anti-SAT editorials in Esquire or the New York Times. Instead, we get attacks on an SAT test that doesn't actually exist (Though it quite possibly may after David Coleman is finished with his reforms).
Though it has long tried to live down the fact for various reasons, the SAT was designed to be what its original name suggests, a scholastic aptitude test. It was also designed to be largely orthogonal to GPA and other information found in high school transcripts. (you can find a more detailed discussion of this point here and here)
In order to achieve that orthogonality the SAT test to be written in such a way that students have taken more advanced classes do not have an unfair advantage. Partly for that reason, the SAT is perhaps unique among major measures of academic accomplishment in that it has almost no rote memory component other than vocabulary.* (From here on out, I am going to focus primarily on the mathematics section though most of the general comments will apply to the entire test.)
An old professor of mine, Bill Condon, once described the analytic SAT as the toughest ninth grade math test you will ever take. That's an extremely apt way of putting it. All of the mathematical concepts are either common sense or things which a ninth grader should have covered. Almost all of the rules and formulas needed for the test are printed in the front of the booklet.
The trouble with coverage of the SAT and to a slightly lesser extent the ACT is that virtually everyone whom you will find discussing it in the pages of a major newspaper or magazine has intense but old and usually highly unreliable memories of the test. Add to that the generally poor quality of the emotionally-charged education reform debate and the result is an incredibly unproductive discussion.
For a representative example, check out this opinion piece written by Jennifer Finney Boylan for the New York Times, which puts the trauma front and center starting with the first sentence:
I WAS in trouble. The first few analogies were pretty straightforward — along the lines of “leopard is to spotted as zebra is to striped” — but now I was in the tall weeds of nuance. Kangaroo is to marsupial as the giant squid is to — I don’t know, maybe D) cephalopod? I looked up for a second at the back of the head of the girl in front of me. She had done this amazing thing with her hair, sort of like a French braid. I wondered if I could do that with my hair.
I daydreamed for a while, thinking about the architecture of braids. When I remembered that I was wasting precious time deep in the heart of the SAT, I swore quietly to myself. French braids weren’t going to get me into Wesleyan. Although, in the years since I took the test in the mid-’70s, I’ve sometimes wondered if knowing how to braid hair was actually of more practical use to me as an English major than the quadratic equation. But enough of that. Back to the analogies. Loquacious is to mordant as lachrymose is to ... uh ...
This was the moment I saw the terrible thing I had done, the SAT equivalent of the Hindenburg disaster. I’d accidentally skipped a line on my answer sheet, early in that section of the test. Every answer I’d chosen, each of those lines of graphite-filled bubbles, was off by one. I looked at the clock. Time was running out. I could see the Wesleyan campus fading before my eyes.
High school is a trauma-filled time and its humiliations and disappointments can stay fresh for decades as they obviously have here. They do not, however, often lead to objective or accurate analyses. It may well have seemed unfair at the time to be judged on knowledge of relatively obscure words, but given that vocabulary tracks fairly well with reading ability, it doesn't seem unreasonable to ask a future English major to display an understanding of words like 'loquacious,' 'mordant' or even 'cephalopod.' As for the math section, I assume from the definite article that "the quadratic equation" refers to the quadratic formula. If so, that's an interesting choice because that formula does not appear on the SAT.
The math that does appear on the SAT relies on the following:
properties of numbers;
basic algebraic manipulation;
very basic (junior high level) geometry (with relevant formulas printed on the first page);
simple probability;
reading graphs and tables;
logic and problem-solving.
All of these fall into the good-to-know category for the general population and I'd argue the last is especially valuable for English majors (bad logic makes for bad literary criticism and often bad literature).
Boylan then goes on to complain that the SAT relies too much on memorization and to argue for the superiority of high school GPA as an academic metric. As mentioned before, the rote learning component of the SAT is extraordinarily small, far smaller than the corresponding component for almost every test-based grade a student will receive in junior high and high school.
This oddly self-defeating argument "We should drop the SAT because it's too ____; instead, we should rely more on grades/other tests/whatever (which happen to be more _____ than the SAT)" also features prominently in a less personal but much less coherent piece by Esquire.com news editor Ben Collins. Collins' argument consists of a series of largely arbitrary but highly emotional associations (it's not entirely clear why he makes these connections but he certainly feels strongly about them).
The first and possibly strangest of these associations involves Google.
Google, a company that evolved from a search engine into the world’s de facto incubator for great ideas that define our future, does not look at standardized tests when they hire applicants. They don't look at whether or not an applicant went to a Holy Grail of the standardized test lottery -- an Ivy League school -- either.The wording here is somewhat unclear (this almost sounds like the company redacts the education sections from applicants' resumes), but I know that the big players like Google are very interested in students coming of top computer science programs like the UC schools and particularly Stanford. Take a look at this SAT breakdown for the school that produced Google:
Score
|
Percent
of Applicants
|
Admit
Rate
|
Percent
of Admitted Class
|
---|---|---|---|
800
|
15%
|
10%
|
25%
|
700–799
|
45%
|
7%
|
54%
|
600–699
|
28%
|
4%
|
19%
|
Below 600
|
12%
|
1%
|
2%
|
Keep in mind that these numbers include humanities majors. The graduates that a company like Google are interested would almost all be in the first two bins. Google doesn't talk much about SATs at least in part because they've largely maxed out the metric.
Collins' piece actually gets worse from there.
All of that is antithetical to the dog-eat-dog, score-high-at-all-costs test-taking culture that America has distilled in its young people. And all of that is exactly why Google is the most futuristic corporation on this planet.
They know that this kind of ingenuity and collaboration — not just knowledge — is what makes a smarter world. It is also what makes better people.
We have ritually and ceaselessly sucked the fun and wonder out of learning in a country that is pushing kids into adulthood aimless, goalless, robotic and depressed as a way to feed a system that we now know does not work.
Then we blame the adults for questioning the intent of that system, even when there is none.
Do not mistake a less-tested America for an Everybody Wins America — an academic extension of those soccer games where nobody keeps score. We need to keep score to stay competitive, to remark on ingenuity and encourage drive, to understand where help is needed and where greatness needs to be challenged further.
But we don’t need to do it in this increasingly antiquated, old-world way, a holdover from when we knew much less about our kids’ biology, how they learn, and how to compel them to be better.
Currently, we have our kids fill in bubbles, and if those kids fill in the bubbles wrong on a forgotten Saturday morning when they are 17, they’re cast to a lower lot for the rest of their lives.
This cannot be the American ideal.
Make no mistake: The next revolution is not another industrial one or another technological one but it will be our first educational one. America can lead the pack if it gets over its hubris, identifies and changes its faults, and unshackles itself from the tyranny of rules and routine that exist only for the sake of themselves.
Why try to play catch up with the old world when the greatest companies in the new economy are already here, in this country, creating new ways to make the world better? These companies are disregarding the rest of the world’s urge to retrofit an exponential stream of new information into a few hundred bubbles on a thin, white sheet of paper.
Only those kinds of companies are forging our future. Why don’t our kids deserve to be taught the same way?
China has better test scores across the board than the U.S. They do not have Apple or Facebook or Microsoft or Google. They do not have our ingenuity. Let’s start appreciating it, rewarding it, fighting for it. Let's start drilling a love of learning into the brains of our kids, in the place where fear and anxiety currently reside.
Where to start...
In some parts of this passage, Collins seems to be talking about some tests other than the SAT such as the PISA exams when addressing China** or VAM-based tests when discussing the effects on learning. If this had led up to a condemnation of tests in general the conflation might be at least internally consistent, but with the paragraph about the importance of keeping score that possibility goes out the window. We have to limit his criticisms, however odd, to the SAT.
The only real specific Collins offers about why the SAT should be singled out for elimination is that the test is old. That's partially true. The test has constantly evolved, driven by some of the best and most sophisticated analytic techniques in the field, but in terms of the test's format and its role in the education system, we've had the current set-up since 1930.
I'd argue that the country has had a pretty good run of innovation since 1930 and while I wouldn't claim that the SAT was a major driver, it would be difficult to argue that it held us back. Collins seems to agree on the first part but he takes a strange turn from there. As best I can make it out, he's arguing that America is the most innovative country in the world so it's essential that we drop a major, longstanding component of our education system or we'll become like China.
All snark aside, we probably should have a good debate about the way college admissions work and about the (I think misplaced) emphasis we have come to put on getting into the 'right' schools. Unfortunately, writers like Boylan and Collins aren't contributing to that debate; they're just supplying misplaced anger and emotional baggage.
*There's a big question (too big to address here) about the role of vocabulary in the SAT. Ideally there should be no rote learning element here at all. The vocabulary component is supposed to measure things like how reading volume and comprehension. Memorizing lists of words is, in a sense, cheating; it's also of questionable effectiveness compared to good, active reading habits.
** From China Daily:
The first annual report on the SAT performance of Chinese students found the average score was 1,213 points out of the total of 2,400, some 296 points lower than US students and 337 points lower than the benchmark set by College Board, the organizer of the test.
The gap is mainly derived from the reading and writing parts of the test. Chinese students scored 170 points less than US students in the reading part, which reveals Chinese students lack training in critical thinking, according to the report.
Chinese students, known to excel in mathematics, earned 547 points out of the total of 800, only 30 points higher than US students. The report attributed the lower-than-expected performance to Chinese students' poor knowledge of English mathematical terms and the test is aimed at a junior level which is easier for US students.
Professional Conduct
Dean Dad has the best view on the Nazareth College decision to rescind a job offer for a philosopher:
I understand the emotional appeal of rejecting someone before she rejects you. It’s psychologically healthy to outgrow that phase. Yes, it’s frustrating when a candidate you’re trying to hire comes in with unrealistic requests. But sometimes grownups have to power through the disappointment. Here’s a phrase I’ve used in turning down unrealistic requests:
“No, sorry, I can’t do that.”It would have likely accomplished the same outcome, without the chilling effect on future negotiations at the college. Colleges have a great situation for hiring in fields like philosophy and it is likely that a much better fit could easily be found.
Thursday, March 20, 2014
Problems with modern reform paradigm
If this is correct then I see a potential problem with school (charter or not) use of standardized tests:
If evaluation is really the goal and we want to make data driven decisions, then are not the testing instruments themselves an important part of the environment? Nobody would trust me to publish data from a Epidemiological study where there were not publically available instruments and public access data sets.
Just look at the value that making NHANES public has generated. Why should we not foster the same openness in education that has been so successful in public health?
Parents don’t want their children’s teachers evaluated on the basis of student standardized test scores because they know it is unfair.Now remember that no instrument is perfect. But under what conditions does it make sense for the tests used to evaluate teachers not be made public? What if there was an error?
– Encouraged by the Obama administration, states now have teacher and principal evaluation systems that include test scores. Unfortunately, many teachers wind up being evaluated on the scores of students they don’t have or subjects they don’t teach.
Parents want to see their child’s standardized tests after completion.
– They can’t. The tests are proprietary.
If evaluation is really the goal and we want to make data driven decisions, then are not the testing instruments themselves an important part of the environment? Nobody would trust me to publish data from a Epidemiological study where there were not publically available instruments and public access data sets.
Just look at the value that making NHANES public has generated. Why should we not foster the same openness in education that has been so successful in public health?
When threads collide -- David Coleman vs. Prof. Feynman
In all the coverage and controversy over the recent changes in the SAT, one of the aspects that troubles me the most is the one that seems to bother most people the least (emphasis added):
The almost inevitable bad outcome will be the nearly unavoidable hit taken by orthogonality. As discussed earlier, the value of a variable (such as an SAT score) in a model lies not in how much information it brings to the model but in how much new information it brings given what the other variables in the model have already told us. Models that colleges use to assess students (perhaps with trivial exceptions) include courses taken and grades earned. We want additional variables to that model to be as uncorrelated as possible with those transcript variables. The math section of the SAT does this by basing its questions on logic, problem solving and on basic math classes that everyone should have taken before taking the SAT. Students whose math education stopped at Algebra I should be on a roughly equal footing with students who took AP calculus, as long as they understood and retained what they learned.
Rather than making the SAT a more effective instrument, "real world" problems only serve to undercut its orthogonality. Meaningful applied questions will strongly tend to favor students who have taken relevant courses. It might be possible to avoid this trap, but it would be extremely difficult and there's no apparent reason for making the change other than the vague but positive connotations of the phrase. (It's important to note here that Coleman's background is in management consulting and the ability to work positive-sounding phrases into presentations is very much a core skill in that field.)
Even more worrisome is the potential for the really bad question, bad enough to have the perverse effect of actually causing more problems (in stress and lost time) for those kids who understand the material. Nothing throws a good student off track worse than a truly stupid question.
Even if the test-makers know what they're doing, writing good, situation-appropriate problems using real situations and data is extraordinarily difficult. The vast majority of the time, real life has to be simplified to an unrealistic degree to make it suitable for a brief math problem. The end result is usually just an old problem with new nouns, take a rate problem and substitute "computer programmer" for "ditch digger."
You can make a fairly good case for real world questions based on teaching-across-the-curriculum -- for example, using Richter scale in a homework problem is a good way of working in some earth science -- but since the purpose of the SAT is to measure, not to instruct, that argument doesn't hold here.
The even bigger concern is what can happen when the authors don't know what they're doing.
From Richard Feynman's "Judging Books by their Covers":
Of course, there are good questions that do use real-world data (you can even find some on the SAT), but in order to write them you need a team that understands both the subtleties of the material and the statistical issues involved in testing it.
The more I hear from David Coleman, whether it concerns the College Board or Common Core, the less confidence I have in his abilities to head these initiatives.
[David] COLEMAN: The new math section will focus on three things: Problem solving and data analysis, algebra and real world math related to science, technology and engineering fields.The response from most journalists and pundits to this push for applicability has been either disinterest or mild approval, but if you dig into the underlying statistics and look into the history of similar educational initiatives, it's hard not to come away with the conclusion that this change pretty much has got to be bad (with a better than even chance of terrible).
The almost inevitable bad outcome will be the nearly unavoidable hit taken by orthogonality. As discussed earlier, the value of a variable (such as an SAT score) in a model lies not in how much information it brings to the model but in how much new information it brings given what the other variables in the model have already told us. Models that colleges use to assess students (perhaps with trivial exceptions) include courses taken and grades earned. We want additional variables to that model to be as uncorrelated as possible with those transcript variables. The math section of the SAT does this by basing its questions on logic, problem solving and on basic math classes that everyone should have taken before taking the SAT. Students whose math education stopped at Algebra I should be on a roughly equal footing with students who took AP calculus, as long as they understood and retained what they learned.
Rather than making the SAT a more effective instrument, "real world" problems only serve to undercut its orthogonality. Meaningful applied questions will strongly tend to favor students who have taken relevant courses. It might be possible to avoid this trap, but it would be extremely difficult and there's no apparent reason for making the change other than the vague but positive connotations of the phrase. (It's important to note here that Coleman's background is in management consulting and the ability to work positive-sounding phrases into presentations is very much a core skill in that field.)
Even more worrisome is the potential for the really bad question, bad enough to have the perverse effect of actually causing more problems (in stress and lost time) for those kids who understand the material. Nothing throws a good student off track worse than a truly stupid question.
Even if the test-makers know what they're doing, writing good, situation-appropriate problems using real situations and data is extraordinarily difficult. The vast majority of the time, real life has to be simplified to an unrealistic degree to make it suitable for a brief math problem. The end result is usually just an old problem with new nouns, take a rate problem and substitute "computer programmer" for "ditch digger."
You can make a fairly good case for real world questions based on teaching-across-the-curriculum -- for example, using Richter scale in a homework problem is a good way of working in some earth science -- but since the purpose of the SAT is to measure, not to instruct, that argument doesn't hold here.
The even bigger concern is what can happen when the authors don't know what they're doing.
From Richard Feynman's "Judging Books by their Covers":
Finally I come to a book that says, "Mathematics is used in science in many ways. We will give you an example from astronomy, which is the science of stars." I turn the page, and it says, "Red stars have a temperature of four thousand degrees, yellow stars have a temperature of five thousand degrees . . ." -- so far, so good. It continues: "Green stars have a temperature of seven thousand degrees, blue stars have a temperature of ten thousand degrees, and violet stars have a temperature of . . . (some big number)." There are no green or violet stars, but the figures for the others are roughly correct. It's vaguely right -- but already, trouble! That's the way everything was: Everything was written by somebody who didn't know what the hell he was talking about, so it was a little bit wrong, always!Keep in mind, Feynman's example was picked to be amusing but representative ("That's the way everything was...a little bit wrong, always"). The post-Sputnik education reformers of his day were making pretty much the same demands that today's reformers are making. There's no reason to expect a better result this time.
Anyway, I'm happy with this book, because it's the first example of applying arithmetic to science. I'm a bit unhappy when I read about the stars' temperatures, but I'm not very unhappy because it's more or less right -- it's just an example of error. Then comes the list of problems. It says, "John and his father go out to look at the stars. John sees two blue stars and a red star. His father sees a green star, a violet star, and two yellow stars. What is the total temperature of the stars seen by John and his father?" -- and I would explode in horror.
Of course, there are good questions that do use real-world data (you can even find some on the SAT), but in order to write them you need a team that understands both the subtleties of the material and the statistical issues involved in testing it.
The more I hear from David Coleman, whether it concerns the College Board or Common Core, the less confidence I have in his abilities to head these initiatives.
Wednesday, March 19, 2014
Differential growth in life expectancy?
There has been a lot of discussion about Annie Lowrey's article on changes in life expectancy, documenting how most of the recent rise in life expectancy is among Americans of higher socio-economic status. I did find the question of causality to be less compelling:
This is the sort of case where data is limited but we still need to make decisions. It is odd that with some decisions we are desperately worried about getting things wrong when it advantages the affluent but we seem quite worried about over-interpreting data when redistribution would be the obvious policy solution.
It is hard to prove causality with the available information. County-level data is the most detailed available, but it is not perfect. People move, and that is a confounding factor. McDowell’s population has dropped by more than half since the late 1970s, whereas Fairfax’s has roughly doubled. Perhaps more educated and healthier people have been relocating from places like McDowell to places like Fairfax. In that case, life expectancy would not have changed; how Americans arrange themselves geographically would have.
“These things are not nearly as clear as they seem, or as clear as epidemiologists seem to think,” said Angus Deaton, an economist at Princeton.It is possible that there is a process of re-arrangement going on. But that still doesn't make charts like the second one in this Aaron Carroll blog post easier to explain. If the higher earning recipients of social security live longer than the lower earning recipients, then this association is not simple to explain with a direct appeal to the ecological fallacy.
This is the sort of case where data is limited but we still need to make decisions. It is odd that with some decisions we are desperately worried about getting things wrong when it advantages the affluent but we seem quite worried about over-interpreting data when redistribution would be the obvious policy solution.
“The best thing that happened to the education system in New Orleans was Hurricane Katrina”
Joseph has already commented on one aspect of this Valerie Strauss article on Netflix CEO Reed Hastings, but a different passage caught my eye.
When we get to effects, however, the picture gets murkier. There has been some improvement in test scores but the 'reforms' coincided with increased spending which would be expected to boost scores. In addition, some of the increase can also be assigned to considerably increased pressure of students to take the tests seriously. Even putting all that aside, the improvements still don't look that impressive when compared to demographically similar schools in other states. Bruce Baker of Rutgers did the heavy lifting.
The bigger story for me, though, is in the details of the now dominant culture of New Orleans schools and in how parents and students have reacted.to the new regime. It's apparent that quite a few people are extremely unhappy.
A previous post mentioned students from one New Orleans high school walking out in a mass protest.
This was not an isolated incident.
He appears to be presenting a vision of education in the United States where nearly all students are educated in collections of charter schools: “So what we have to do is to work with school districts to grow steadily, and the work ahead is really hard because we’re at 8% of students in California, whereas in New Orleans they’re at 90%, so we have a lot of catchup to do.”As indicated by the Arne Duncan quote I used as a title, the notion of New Orleans as the educational ideal is strongly established in the reform movement. New Orleans has implemented the major tenets of the reform pedagogy to an extraordinary degree, particularly the rigid, metric-driven, no-excuses attitude. On this much, everyone can pretty much agree.
When we get to effects, however, the picture gets murkier. There has been some improvement in test scores but the 'reforms' coincided with increased spending which would be expected to boost scores. In addition, some of the increase can also be assigned to considerably increased pressure of students to take the tests seriously. Even putting all that aside, the improvements still don't look that impressive when compared to demographically similar schools in other states. Bruce Baker of Rutgers did the heavy lifting.
The bigger story for me, though, is in the details of the now dominant culture of New Orleans schools and in how parents and students have reacted.to the new regime. It's apparent that quite a few people are extremely unhappy.
A previous post mentioned students from one New Orleans high school walking out in a mass protest.
This was not an isolated incident.
Sci Academy, the flagship of the Collegiate Academies charter group, is known for high test scores and stringent discipline policies, such as requiring students to walk between lines taped on the floor. School leaders say the two go hand-in-hand: You don't have to walk on the right side of the hallway in college, but the discipline will serve you well.Anyone with experience with K-12 education can tell you that mass suspension and expulsion may possibly be the simplest and most effective way of improving test scores and making classroom management easier (a particularly pressing issue if you have high teacher turnover and rely heavily on programs like TFA). The problem with the technique is that it takes its greatest toll on the most vulnerable students. To fully grasp the brutality of these methods, you have to look at specific examples, such as this one from a parents' advocate in New Orleans:
But students at the group's two new schools, George Washington Carver Collegiate Academy and George Washington Carver Preparatory Academy, walked out the week before Thanksgiving, angry about such rules. On Wednesday (Dec. 18), about 60 students attended a rally. A letter of demands written by some students said kids were being suspended "for every little thing."
Recent state data show there are grounds for that claim. The three Collegiate schools had the city's highest suspension rates in the 2012-13 academic year. A full 69 percent of Carver Collegiate's student body was sent home at least once. Carver Prep suspended 61 percent of its student body. Sci Academy sent home 58 percent, a 9-point increase from the year before.
The case that still breaks my heart involved a 14-year-old who kept getting demerits because his uniform shirt was too small and came untucked basically every time he moved. His mother was a veteran, well-educated, and had sold real estate but got divorced and ended up losing her job, and became homeless. They were living with friends and really struggling. The school expelled the child because he’d had three suspensions—the last one for selling candy to try to raise enough money to buy a new shoes and a new uniform shirt. I felt that if the mother went and told her story that the school would understand and wouldn’t hold up the expulsion. She didn’t want the school to know how impoverished she was but I convinced her to do it, so she came and told all of these people what she was going through—about her struggles. I thought for sure the board would overturn the expulsion, not just because her story was so compelling, but because there wasn’t actually anything in the school’s discipline book about selling candy. But they upheld it and it broke my heart that this kid was being put out of school because he was poor.I don't know if this student went to one of the specific schools discussed here, but I can tell you that this is all too often what the process looks like, which is why responsible administrators use it so reluctantly.
Tuesday, March 18, 2014
A rare RPG post
Go and read Greyhawk Grognard on rare spell components. With creativity you can make powerful spells tough to cast without needing to simply make them cost cash. Finding each of these components would be an adventure in and of itself. It makes components fun and interesting instead of just a "pay go" system.
Has this person ever worked in a large corporation?
I ask in astonishment because I read things like this:
It also leads to other tough questions. The reason that the private sector works well is "creative destruction" as better companies outcompete poorer companies. Is the charter school movement going to be immune to competition as well?
And if they are immune to market forces, what are they accountable to? If we think the answer is a higher level of government, then why do we think it will be more stable and more accountable than the school boards?
This is not so much a defense of school boards (which I have seriously mixed feelings about) as it is a question of what model do we replace them with? I am not sure that the command and control style socialist model of the state owned or supported corporation has been the most efficient alternative, has it?
EDIT: Mark Palko wanted me to mention that Valarie Strauss has been going good work in this area for some time. Also note that idea of California needing to "catch up" to New Orleans -- it is possible for a former backwater to become dynamic (think Macedonia at the end of the classical Greek era) but this is often not the best bet to make.
NOTE: Mark here. For a bit more context, check out the reform movement gadfly Edushyster's take on the charter chain Hastings was promoting,
The newest bit of “wisdom” for public education comes to us from Netflix Chief Executive Officer Reed Hastings, who is a big charter school supporter and an investor in the Rocketship Education charter school network. At a meeting of the California Charter Schools Association on March 4, he said in a keynote speech that the problem with public schools is that they are governed by elected local school boards. Charter schools have boards that are not elected and, according to his logic, have “a stable governance” and that’s why “they constantly get better every year.”See, in the private sector there was this phenomenon called "re-organization" (or re-org) for short that seemed to hit every couple of years. Each time there was a massive shift in governance and lines of reporting. If Netflix has managed to avoid these "re-orgs" then I see that as a very positive feature of the company, but it is hardly a guarantee that all private corporations will be able to do the same things.
It also leads to other tough questions. The reason that the private sector works well is "creative destruction" as better companies outcompete poorer companies. Is the charter school movement going to be immune to competition as well?
And if they are immune to market forces, what are they accountable to? If we think the answer is a higher level of government, then why do we think it will be more stable and more accountable than the school boards?
This is not so much a defense of school boards (which I have seriously mixed feelings about) as it is a question of what model do we replace them with? I am not sure that the command and control style socialist model of the state owned or supported corporation has been the most efficient alternative, has it?
EDIT: Mark Palko wanted me to mention that Valarie Strauss has been going good work in this area for some time. Also note that idea of California needing to "catch up" to New Orleans -- it is possible for a former backwater to become dynamic (think Macedonia at the end of the classical Greek era) but this is often not the best bet to make.
NOTE: Mark here. For a bit more context, check out the reform movement gadfly Edushyster's take on the charter chain Hastings was promoting,
Monday, March 17, 2014
Texas versus California
I have been trying to decide if Scott Lemieux covered this too completely, but I decided that there were a couple of useful points in this article. Especially as relates to my California versus Texas discussion with Mark, where we discuss the relative merits of the two states. For example:
Even more telling:
And despite all the gloating by Texas boosters about how the state attracts huge numbers of Americans fleeing California socialism, the numbers don’t bear out this narrative either. In 2012, 62,702 people moved from California to Texas, but 43,005 moved from Texas to California, for a net migration of just 19,697.This really points out how marginal the population shift is. It isn't zero, but it is also not a mass population shift driven by the hellish California region.
Even more telling:
Oh yes, I know what you’ve heard. And it’s true, as the state’s boosters like to brag, that Texas does not have an income tax. But Texas has sales and property taxes that make its overall burden of taxation on low-wage families much heavier than the national average, while the state also taxes the middle class at rates as high or higher than in California. For instance, non-elderly Californians with family income in the middle 20 percent of the income distribution pay combined state and local taxes amounting to 8.2 percent of their income, according to the Institute on Taxation and Economic Policy; by contrast, their counterparts in Texas pay 8.6 percent.
And unlike in California, middle-class families in Texas don’t get the advantage of having rich people share equally in the cost of providing government services. The top 1 percent in Texas have an effective tax rate of just 3.2 percent. That’s roughly two-fifths the rate that’s borne by the middle class, and just a quarter the rate paid by all those low-wage “takers” at the bottom 20 percent of the family income distribution. This Robin-Hood-in-reverse system gives Texas the fifth-most-regressive tax structure in the nation.That leads to some really interesting questions about he relation of tax rates to prosperity. If most people in Texas pay more taxes than California, then maybe this is another data point on the scale of more money for government leading to a stronger and more prosperous state. But these points really don't make the case that Texas is clearly better than California. Now both states have a strong streak of pro-business advocates, and so I think that both could end up as engines of American prosperity. But I think that the future for California is pretty optimistic once the actual facts are broadly considered.
Sunday, March 16, 2014
The second half is more remarkable
Paul Krugman:
But the second part is the piece that I find truly remarkable. I mean how hard could it be for the media to fact check that raising eligibility to 65 is current law? Sure, you might want to protect the law but that is a completely different argument for forgetting that the low changed in 1983. Or you could want to phase it in faster, but that would also be a) a different argument and b) seemingly ill-timed with the changes in the 401(k) system.
So I could imagine some debate about the first part (based around potential short term trends and the fact that we don't have the complete death curve for the population). But the second is simply . . . odd.
But my guess is that in a week or two we will once again hear a supposed wise man saying that we need to raise the retirement age to 67 because of higher life expectancy, unaware that (a) life expectancy hasn’t risen much for half of workers (b) we’ve already raised the retirement age to 67.I completely understand why part a is misleading -- poorer workers get less social security already and making them work longer means fewer years of benefits increasing the benefits to wealthier contributors, who already get more per month.
But the second part is the piece that I find truly remarkable. I mean how hard could it be for the media to fact check that raising eligibility to 65 is current law? Sure, you might want to protect the law but that is a completely different argument for forgetting that the low changed in 1983. Or you could want to phase it in faster, but that would also be a) a different argument and b) seemingly ill-timed with the changes in the 401(k) system.
So I could imagine some debate about the first part (based around potential short term trends and the fact that we don't have the complete death curve for the population). But the second is simply . . . odd.
Friday, March 14, 2014
This was both entertaining and thought-provoking
It was also a very clear headed explanation of some of the key mythologies of the modern cult of anarcho-capitalism. I especially liked (edited with *'s for questionable language choices):
But it is a very straightforward explanation of the concept of interdependence, and the way that we are all connected based on social convention.
Sometimes the Cracked site is surprisingly thought provoking.
But if none of that stuff existed, there would be nothing stopping Jay-Z from taking your farm. In other words, you don't "own" ****. The entire concept of owning anything, be it a hunk of land or a house or a ****ing sandwich, exists purely because other people pay other armed men to protect it. Without society, all of your brave, individual talents and efforts won't buy you a bucket of ****s. So when I say "We're all in this together," I'm not stating a philosophy. I'm stating a fact about the way human life works. No, you never asked for anything to be handed to you. You didn't have to, because billions of humans who lived and died before you had already created a lavish support system where the streets are all but paved with gold. Everyone reading this -- all of us living in a society advanced enough to have Internet access -- was born one inch away from the finish line, plopped here at birth, by other people.
But it is a very straightforward explanation of the concept of interdependence, and the way that we are all connected based on social convention.
Sometimes the Cracked site is surprisingly thought provoking.
Orthogonality and the SAT
[Note: 'SAT' refers to the SAT Reasoning
Test]
If you spend any time following the SAT
debate, you will frequently encounter some variation on the phrase:
All in all, the changes are intended to make SAT scores more accurately mirror the grades a student gets in school.
The thing is, though, there already is something that accurately mirrors the grades a student gets in school. Namely: the grades a student gets in school. A better way of revising the SAT, from what I can see, would be to do away with it once and for all.
Putting aside the questionable
assumption that the purpose of a colleges selection process is to
find students who will get good grades at that college, there is a
major statistical fallacy here, and it reflects a common but very
dangerous type of oversimplification.
When people talk about something being
the "best predictor" they generally are talking about
linear correlation. The linearity itself is problematic here – we
are generally not that concerned with distinguishing potential A
students from B students while we are very concerned with
distinguishing potential C students from potential D and F students –
but there's a bigger concern: The very idea of a "best"
predictor is inappropriate in this context.
In our intensely and increasingly
multivariate world, this idea ("if you have one perfectly good
predictor, why do you need another?") is rather bizarre and yet
surprisingly common. It has been the basis of arguments that I and
countless other corporate statisticians have had with executives over
the years. The importance of looking at variables in context is
surprisingly difficult to convey.
The explanation goes something like
this. If we have a one-variable model, we want to find the predictor
variable that gives us the most relevant information about the target
variable. Normally this means finding the highest correlation between
some transformation of the variable in question and some
transformation of the target where the transformation of the target
is chosen to highlight the behavior of interest while the
transformation of the predictor is chosen to optimize correlation. In
our grading example, we might want to change the grading scale from A
through F to three bins of A/B, C, and D/F. If we are limited to one
predictor in our model picking, the one that optimizes correlation
under these conditions makes perfect sense.
Once we decide to add another variable,
however, the situation becomes completely different. Now we are
concerned with how much information our new variable adds to our
existing model. If our new variable is highly correlated with the
variable already in the model, it probably won't improve the model
significantly. What we would like to see is a new variable that has
some relationship with the target but which is, as much as possible,
uncorrelated with the variable already in the model.
That's basically what we are talking
about when we refer to orthogonality. There's a bit more to it – –
we are actually interested in new variables that are uncorrelated
with functions of the existing predictor variables – but the bottom
line is that when we add a variable to a model, we want it to add
information that the variables currently in the model haven't already provided.
Let's talk about this in the context of
the SAT. Let's say I wanted to build a model predicting college GPA
and, in that model, I have already decided to include high school
courses taken and their corresponding grades. Assume that there's
an academic achievement test that asks questions about trigonometric
identities or who killed whom in Macbeth. The results of this test
may have a high correlation with future GPA but they will almost
certainly have a high correlation with variables already in the
model, thus making this test a questionable candidate for the model.
When statisticians talk about orthogonality this is the sort of thing
they have in mind.
The SAT works around this problem by
asking questions that are more focused on aptitude and reasoning and
which rely on basic knowledge not associated with any courses beyond
junior high level. Taking calculus and AP English might help
students' SAT scores indirectly by providing practice reading and
solving problems so we won't get perfect orthogonality but it will
certain do better in this regard than a traditional subject matter
exam.
This is another of those posts that sits in the intersection of a couple of major threads. The first concerns the SAT and how we use it. The second concerns orthogonality, both in the specific sense described here and in the general sense of adding information to the system, whether through new data, journalism, analysis or arguments. If, as we are constantly told, we're living in an information-based economy, concepts like orthogonality should be a standard feature of the conversation, not just part of statistical esoterica.
Thursday, March 13, 2014
Negotiation
This is a really interesting story about a failed academic negotiation. It is pretty clear that nobody has covered themselves in glory here, although the response from the institution seems awfully harsh and a symptom of the sort of extremely tight labor markets that reduce employee choice. One only hopes that the maternity leave condition was orthogonal to the decision to rescind the offer, although I suspect asking for a one year delay in start date was more likely as the culprit.
The comments below are quite interesting as well.
The comments below are quite interesting as well.
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