Friday, October 31, 2014


This is Joseph.

We’re all familiar with the critiques of standardized tests and other common measures used for high-stakes decisions.  Recently, somebody in my circle has started going on about measures of “grit” and their predictive power.  I am willing to believe that “grit” is an excellent predictor of all sorts of things.  But I wonder if much of the predictive power of “grit” comes from the fact that these measures are currently low-stakes, so people have few incentives to game them.
 I really think that this is the heart of the measurement problem.  Insofar as there is a way to do better on a test, in a way that is less work than just be really good at it, then it is probable that much of your signal will be gaming.  Studying the form of the question, for example, is likely to improve performance (by less confusion, if nothing else) but access to these approaches may vary by context.

Even worse, some of the test prep may have nothing to do with the underlying measure.  So the score starts to measure things like "willingness to sacrifice learning time for test prep time". 

This is a very good insight and likely to be eternally problematic in education. 

Thursday, October 30, 2014

Old story, new setting

I realize we've hammered this point quite a bit but, for their own good as well as the public's, charter schools have got to come up with an aggressive plan to deal with the self-dealing, price gouging and general looting that is becoming widespread in places like Michigan, Florida and Ohio.

From the Toledo Blade:
The charter school Imagine School for the Arts is paying rent of nearly $1 million a year on a downtown building with the education funding it gets from the state, prompting criticism from a progressive advocacy group that studied charter-school finances around the state.

The complicated financial arrangement also involves a school-affiliated trust company spending more than $7 million last year to buy a building valued at less than $2 million.

The liberal advocacy group ProgressOhio attacked the size of the rent payments at charter schools operated in Toledo and other Ohio cities by Imagine Schools Monday as excessive. Imagine is a national for-profit educational management company.

According to ProgressOhio, Imagine’s subsidiary, Schoolhouse Finance, collected at least $14.4 million in public money last year for the company’s 17 Ohio schools. Of that, $8.9 million covered rent for long-term leases to Schoolhouse Finance. The $5.5 million balance went to pay “indirect costs” to Imagine to provide management services.

Wednesday, October 29, 2014

Mark says smart stuff

This is Joseph

In the context of a recent post by Mark Palko:
Both the tech and financial sector have embraced the idea that economic rewards are directly correlated to work and worth. It's a strange mixture of efficient market theorem and social Darwinism, often with more than a bit of Randianism.
I found both of these arguments for increased taxation of high income earners interesting.   First:
Because rich people spend their money on useless stuff. Not far from where I live, there is a new house going up. It will be over 10,000 square feet when it is complete. 2,500 of those square feet will be a closet that has two separate floors, one for regular clothes and one for formal wear. If that is what you are spending your money on, then yes, I believe raising your taxes to fund education, infrastructure, and health spending is a net gain for society.

Don’t poor people spend money on stupid stuff? Of course they do. Isn’t the government an inefficient provider of some of these goods, like education? Maybe. But even if both those things are true, public investment and/or transfers to poor people will result in some net investment that I’m not currently getting from the mega-closet family. I’m happy to talk about alternative institutional settings that would ensure a greater proportion of the funds get spent on actual investments.

Because I’m not afraid that some embattled, industrious core of “makers” will decide to “go Galt” and drop out of society, leaving the rest of us poor schleps to fend for ourselves.  Oh, however will we figure out how to feed ourselves without hedge fund managers around to guide us?
I think that this points out that the notion that people deserve the actual income/wealth that they currently have, in some sort of fundamental way, is a true measure of worth/contribution.  It is true that rich people do pay taxes, but consider all of the benefits they get?  We have a whole society of laws devoted to reducing kidnapping, murder of near kin, and robbery, and the wealthy definitely benefit from this. 

So I am not saying that the current level of taxes is too low, too high, or just right (on any specific segment of the market).  I am saying that an open discussion should consider issues like "everybody spends money to satisfy desires and that these desires rarely pass the scrutiny of outside parties".  Or that the whole idea of "going Galt" is often rather silly.  In academics, we have many good people for every position.  The marginal loss of any one person is sad but does not destroy the whole enterprise. 

Similarly, I suspect that there are a number of possible hedge fund managers in the world who could do a relatively comparable job (at least insofar as society as a whole matters -- losing your superstar investor could be a private tragedy).  Otherwise we'd expect the market to collapse when one of these key people dies of old age (and the market has been pretty robust to replacements via death so far). 

So some points to ponder. 

This is the perfect October clip

At least for a snarky epidemiology blog...

Tuesday, October 28, 2014

Graphs that make me nervous -- UPDATED

[Here's a good link to the full report.]

A couple of quick caveats: I am never entirely comfortable focusing too much on "additional years of learning" -- it's a problematic metric -- and the link to the original report seems to be dead.

The good folks at Vox are very excited by the results of this recent experiment in merit pay. Perhaps I'm missing something obvious, but that jump between 2010 and 2009 seems really big.

Does this look odd to anyone else?

Yes, a Surgeon General would come in handy right about now

For me, one of the most interesting stories in politics these days is the way that information has come to flow in the the conservative movement. And sometimes the most interesting part of that story is the way information fails to flow.
Rep. Jason Chaffetz (R-Utah) says Ron Klain is "off to a bad start" in his new role as the president's Ebola response coordinator, and that the U.S. Surgeon General should be the one leading the effort. But what Chaffetz doesn't seem to realize is that there hasn't been a surgeon general for more than a year.

“Why not have the surgeon general head this up?" Chaffetz asked in a Wednesday appearance on Fox News. "I think that’s a very legitimate question. At least you have somebody who has a medical background whose been confirmed by the United States Senate.”

“It begs the question, what does the surgeon general do?" he added. "Why aren’t we empowering that person?”
After this broke, Chaffetz tried to moonwalk his way back from the statement but there is simply no way to frame this so that the man comes off as both well-informed and honest. His problem is that he is trying to follow an official party line that makes consistency almost impossible (you can't block relevant nominations and gut relevant funding while plausibly complaining about the government doing too little to address an epidemic).

I suspect the root of the problem is that the leadership of the conservative movement fell in love with the appealing but doubly flawed idea that you can create optimal messaging by controlling the process. Fox News has always been a hothouse for ideas and arguments crafted to appeal to the base. Conflicting data and effective counter-arguments were largely kept out of the environment.

This approach can work for a while but at some point you lose control. The system is too complex to fine-tune. Eventually you find yourself saddled with a bunch of ideas that the base is committed to even though they can't hope to survive in the outside world.

"—We Also Walk Dogs"

I've been going through some old posts on incentive pay and they got me thinking about how education reformers, fresh water economists and libertarians often fall back on a strongly linear model. That, in turn, got me thinking about a Heinlein story I read years ago.

From Wikipedia:
"—We Also Walk Dogs" is a science fiction short story by Robert A. Heinlein. One of his Future History stories, it was first published in Astounding Science Fiction (July 1941 as by Anson MacDonald)....

'General Services', a very successful company that provides various personal services ... is asked to ... enable an interplanetary conference to be held on Earth, whose strong gravity is inhospitable to many of the native races of other planets in the solar system.

Much of the action of the story is ... about how to persuade the world’s leading physicist to undertake the job.
As memory serves, that really is the gist of the story. Find the right person, offer him or her sufficient incentive, get what you want. Add to that an entrepreneur hero...

Monday, October 27, 2014

Optimization and college enrollments

This is Joseph.

Dean Dad had a great post a while back on trying to improve classroom scheduling.  In it, he had a great example of the perils of overfitting.  The context is that the Gates Foundation had suggested that a more efficient algorithm for classroom management could improve costs.  The problem is that they aren't testing this in prospective environments -- leading to some issues:
Finally, and I can’t stress this enough, enrollment is a moving target.  Patterns change unevenly, so in any given year you’ll get a fresh new crop of anomalies.  When enrollment continues until just before classes start, as is typical at community colleges, you’re left making predictions based on partial information.  And you have to make those predictions early enough for alternate plans to be realistic.  That’s never a perfect science -- every year, someone complains that his course would have filled if we had just given it more time, which is unprovable either way -- but it’s inherent in being “responsive.”  If we locked down enrollments months in advance, we would have time to squeeze out some efficiencies.  With numbers changing until the last minute, it’s harder.  You’ll never capture that if you only look at “snapshots.”
It's also worth noting that the staffing side is also an issue.  Paying for "Just in time" staffing for a community college would almost certainly reduce the qualifications of the instructors, do strange things to the workload of permanent staff, or increase prices.  After all, if you do not know if you are going to be taking a class until the first day of classes (when enrollments are likely close enough to know) then you will likely charge more or look for another job.  Landlords are notoriously unsympathetic to "most of the time this works and I can pay rent" pleas.

So the report might be interesting as an estimate of the maximum possible benefit.  But in the real world you never get 100% efficiency in any process, especially one that has ebbs and flows.  Even McDonalds, good as they are (and they are really good at this) cannot completely eliminate wait times due to the lunch rush. 

Mark Evanier points out the fundamental contradiction in conservative complaints about Hollywood's "political correctness"

Mark Evanier is one of LA's leading pop culture experts (and in this town that's a high bar). He's been writing for television and comics for around forty years now and probably writing about them for even longer so when it comes to things like the process of creating cartoons for television, he speaks from a position of authority.

Something that can't really be said for Tucker Carlson,
Nothing is scarier to a modern liberal than tobacco. If Popeye were driving around giving the morning after pill to fourth graders that would be totally fine. But smoking a pipe, a symbol of freedom and masculinity in America itself, the reason this country exists, tobacco, that's like, "Oh, that's outrageous. That's a major sin."
As you probably guessed, Carlson was ranting about a clip from a proposed Popeye cartoon (from the gifted Genndy Tartakovsky). He was also misrepresenting the way cartoons get made. Evanier sets him straight.
The other thing Mr. Carlson doesn't get about it is that this is not a political decision. It's a marketing concern. Most of the time when someone decides to launder animation — tone down sex or violence — it's because they want to make sure they can sell reruns of the product to the widest audience for the longest time.

About ten years ago, I was approached about writing a Popeye animated project. It never happened but we had a meeting or two and it was made pretty clear to me that merchandising and marketing were driving this particular venture; that any decision about Popeye having a pipe or Popeye punching out Bluto would be decided on that basis. They were going to make some assessment based on an estimate of how many parents wouldn't buy a toy if the character had a pipe…or how many countries or networks wouldn't buy and air the show.

A principle Tucker Carlson has voiced as long as I've followed him on TV is that companies should be free from regulation and outside pressures that might minimize their profit margins. And now here he is, arguing that the people who are marketing Popeye need to give Popeye his pipe. Someone needs to ask Carlson, "Even if they think they'll make less money if they do?" Because if they don't give Popeye a pipe, that'll be the reason.

... That's all that's involved here. No politics. No hidden agenda. Just someone's idea of how to exploit a property.
There has always been a significant enemy-of-my-enemy quality to the alliance of social and pro-business conservatives. The small town pastor and the big city banker never really trusted each other but their interests often aligned.

What has changed is the nature and scope of right-wing media. A list of the causes would probably be the stuff of a Ph.D. thesis, but it would certainly include the explosion of cable channels and the death of the Fairness Doctrine. Whatever the reason, there is now a major industry built around supplying hundreds of hours a week of a very specific kind of news and commentary.

Fox News is targeted mass media. What's more, it's targeting people who feel abandoned, even disenfranchised by the media at large (yes, I realize we're talking about sixty-year-old, upper and upper-middle class white guys, but we're also talking about perceptions). Rants about Popeye's pipe play well with that audience, as do most complaints about Hollywood liberals.

The argument of media liberal bias has always had a problem reconciling the position with the cost factor ("Freedom of the press is guaranteed only to those who own one." -- A.J. Liebling), but fifty or one hundred years ago when moguls acted more independently, there were examples of rich liberal moguls who were willing to sometimes put principle and even whim above profits (Turn of the Century Hearst comes to mind). In the Twenty-first Century, the vast majority of media is controlled by a handful of huge corporations. The suggestion that these companies are putting a progressive agenda ahead of profits strains credulity.

Saturday, October 25, 2014

Three films

Sometimes, in the course of researching a post, a link leads to a completely unexpected corner of the internet. In this case, a post on Mark Evanier lead here.

The first is a cameraless film with hand-drawn sound from before the war, the second explains the technique and the third stands alone.

Norman McLaren - Dots (1940)

Friday, October 24, 2014

Have you had your flu shot yet?

This is Joseph

I was reading Mike the Mad Biologist's web page and I noted this article on Ebola and the flu.  Ebola has been in the news a lot but influenza remains a bigger killer than Ebola:
Ebola has claimed fewer than 4,000 lives globally to date, none in the United States. Flu claims between 250,000 and 500,000 lives every year, including over 20,000 in the United States—far more American lives than Ebola will ever claim.
Notice just how terrible the Spanish flu was:
It infected 500 million people across the world, including remote Pacific islands and the Arctic, and killed 50 to 100 million of them—three to five percent of the world's population
Today, that would be a disease that killed between nine and fifteen million Americans.  And the easiest option to reduce risk is to vaccinate against the infection. 

Have you had your flu vaccine?  [I get mine annually, usually on the first day it is permitted]

When journalists have an ethical obligation to roll their eyes...

...or at least ask a follow-up question.

Maybe it's just me, but don't journalists have an obligation to object when sources say something blatantly, laughably untrue? If the subject of an interview has just insulted the intelligence of your readers, should you at least attempt to get a more truthful response?

Andrew Cuomo has a new book out. To promote it he has a brief interview with Amy Chozick in the New York Times. I realize that this isn't a setting where you expect hard-hitting journalism, but this still stands out.
You also write that there are ultimately more negatives than positives to being a famous politician’s son. Why? I wouldn’t trade my father or our experiences for anything. But politically, it’s a negative, because you get all your father’s enemies — and not all his friends.
As Scott Lemieux observes, "It’s amazing how many public officials in this land have managed to get beyond this handicap anyway." Everyone knows that Cuomo's background gave him an enormous advantage. He knows it. Chozick knows it. Her editor knows it. We know it.

However, Cuomo also knows that no no one at the NYT is going to rock this particular boat. It's possible that Chozick asked some kind of follow-up -- the article includes the rather troubling disclaimer "INTERVIEW HAS BEEN CONDENSED AND EDITED".-- but the piece that I saw just moves on.

Thursday, October 23, 2014

David Brooks, con(firmation) artist

[picking up where we left off here]

David Brooks has one of the most desirable jobs in journalism; it is also one of the most difficult. He has to present a mainstream conservative perspective in a way that appeals to his center-left target audience (which includes but is somewhat larger than the target audience of the New York Times). His job is greatly complicated by shifts in the Republican Party and the conservative movement. On a growing number of issues there is less and less common ground to focus on.

Fortunately for Brooks, there is a (hopefully unwritten) loophole in the professional standards of the NYT and many other publications which allows writers to break all sorts of rules -- up to and including the one against making things up -- as long as these lapses serve to reinforce the readers' (or at least the editors' and publishers') preconceptions.

The target audience for the NYT is mainly in the top half (possibly top quartile) in terms of wealth and education. They may not be Randian but they still tend to look at the bottom quartile with an attitude that is by turns suspicious and patronizing. Check out how Brooks plays to those prejudices in this recent column (via Charles Pierce).
In the first place, we’re living in a segmented society. Over the past few decades we’ve seen a pervasive increase in the gaps between different social classes. People are much less likely to marry across social class, or to join a club and befriend people across social class.

That means there are many more people who feel completely alienated from the leadership class of this country, whether it’s the political, cultural or scientific leadership. They don’t know people in authority. They perceive a vast status gap between themselves and people in authority. They may harbor feelings of intellectual inferiority toward people in authority. It becomes easy to wave away the whole lot of them, and that distrust isolates them further. “What loneliness is more lonely than distrust,” George Eliot writes in “Middlemarch.”

So you get the rise of the anti-vaccine parents, who simply distrust the cloud of experts telling them that vaccines are safe for their children. You get the rise of the anti-science folks, who distrust the realm of far-off studies and prefer anecdotes from friends to data about populations. You get more and more people who simply do not believe what the establishment is telling them about the Ebola virus, especially since the establishment doesn’t seem particularly competent anyway.
This is brilliantly Brooksian. The first paragraph is accurate and well-grounded. The second is where things start getting subtle. The transition from fact to inference is so smooth and the conclusions he draws are so reasonable that few readers will realize how skillfully they've been set up.

Note the patronizing, more-to-be-pitied-than-censured tone. In his detached, scholarly, Middlemarch-quoting way, Brooks sympathizes with those in the lower class. He understands how conditions have made them angry, resentful and suspicious and how those emotions have made them gullible and prone to hysteria.

Having framed the question in such reasonable terms and having masterfully played on the prejudices of his readers, Brooks feels free to start making things up. Pretty much all the statements in the third paragraph are lies of varying degree, but Brooks knows they are lies most of his readers were predisposed to believe.

Working backwards (which allows us to save the best for last), let's start Ebola. Brooks is basically talking about the sort of thing we've been hearing from this guy (to get the full effect, go back and read the second paragraph).

How about the broader anti-science question? Brooks credits it to the great unwashed sharing misinformation but he offers no data to back it up, but if we look at the most obvious example (denial  of global warming), there is an alternative explanation that does have considerable evidence to support it.  George Will also figures prominently in this one.

And finally, how about the resentful and suspicious lower classes driving the anti-vaccination movement?

Not so much:
Exemption rates vary greatly by area and school. Los Angeles Unified kindergartens, for example, had an overall exemption rate of just 1.6%, although there are several in the district where more than 8% of students have belief exemptions. At Santa Monica-Malibu Unified, the overall exemption rate was 14.8% and at Capistrano Unified in south Orange County, it was 9.5%. At nearby Santa Ana Unified only 0.2% of kindergartners had exemptions on file.

In Los Angeles County, the rise in personal belief exemptions is most prominent in wealthy coastal and mountain communities, The Times analysis shows. The more than 150 schools with exemption rates of 8% or higher for at least one vaccine were located in census tracts where the incomes averaged $94,500 — nearly 60% higher than the county median.

Brooks has been doing this sort of thing for a long time now, long enough for the NYT to know what's going on..

Wednesday, October 22, 2014

Another one for the West Coast Stat View Lexicon -- Farpotshket

I'm just a good ol' Arkansas boy (and a lapsed Presbyterian to boot) so I don't know from Yiddish, but for anyone discussing education reform, this one is indispensable.

From the inexplicably good

#8. "Farpotshket" (Yiddish) 
What It Means: 
Something that was a little bit broken ... until you tried to fix it. Now it's totally screwed.
To demonstrate the usefulness of "farpotshket," look no further than that nightstand you picked up at your friendly neighborhood IKEA. You know, the one that sits completely cockeyed but, goddammit, still does its job so long as you don't hit the snooze on your alarm clock too hard and send everything sliding off onto the floor. Then one day you finally get ambitious and think, "Hell, all I need to do is shorten the other three legs and make it level again! I can do that!" Six hours and a pile of sawdust later, you now have an unusable 12-inch-tall table that, by the way, still wobbles. In Yiddish, you have a farpotshket on your hands.

"The skeptics are wrong all the time"

Marc Andreessen has a new interview up and it is characteristically packed with silliness. If things had gone better for ViolaWWW, do you think Pei-Yuan Wei would have gotten this annoying?

What did you do?

I just went to college. I did my thing. I came out here in ’94, and Silicon Valley was in hibernation. In high school, I actually thought I was going to have to learn Japanese to work in technology. My big feeling was I just missed it, I missed the whole thing. It had happened in the ’80s, and I got here too late. But then, I’m maybe the most optimistic person I know. I mean, I’m incredibly optimistic. I’m optimistic arguably to a fault, especially in terms of new ideas. My presumptive tendency, when I’m presented with a new idea, is not to ask, “Is it going to work?” It’s, “Well, what if it does work?”

But clearly you don’t think everything’s going to work.

No. But there are people who are wired to be skeptics and there are people who are wired to be optimists. And I can tell you, at least from the last 20 years, if you bet on the side of the optimists, generally you’re right.

On the other hand, if there’d been a few more skeptics in 1999, people might have kept their retirement money. Isn’t there a role for skepticism in the tech industry?

I don’t know what it buys you. Let me put it this way. If you could point to periods of time in the last hundred years when everything just stabilized and didn’t change, then maybe yes. But that never seems to actually happen. The skeptics are wrong all the time.

There is a huge survivor bias in the way Andreessen and other creative disruptors compile their case studies. They only remember the lottery tickets that paid off and this leads them to dispense some very bad advice.

When it comes to investing in innovation, skeptics are right a lot -- quite possibly most -- of the time. We've been at this for well over a century, at least since Edisonades started showing up next to the dime Westerns. If you couldn't be a Bell or a Wright, you could at least be the investor who got in on the ground floor.

The trouble was, then and now, that there tend to be more Paige Compositors than light bulbs. Uncritical blanket optimism is a bad way to approach investments. I'd also argue that, if you're setting your sights higher than Snapchat, it's also a bad way to promote innovation but that's a topic for another post.

Tuesday, October 21, 2014

This is why I think nobody cares about the debt

Over in Canada, Frances Woolley takes on the question of should the elimination of the deficit lead to immediate tax cuts.  Seriously.  Read and marvel at these quick facts:

From 2008–09 through 2013–14, the Government has delivered tax reductions totalling more than $60 billion to job-creating businesses.

According to KPMG, total business tax costs in Canada are now the lowest in the Group of Seven (G-7) and 46% lower than those in the United States.

Personal income taxes are now 10% lower with the tax relief provided by the Government since 2006. For an average family of four, taxes have been cut by close to $3,400. 

Once the federal budget is balanced, the Government’s first priority will be to provide further tax relief to hard-working Canadian families
So, after a ton of tax cuts (look at points 2 and 3), the clear priority is more tax cuts.  Under this rubric the debt will never, ever be paid down.  After all, I am not a financial genius, but paying down debt requires at least some period of running a surplus.

Now there may be all sorts of reasons that running a long term debt is a sane and responsible thing to do.  After all, governments are not households and many of my household intuitions are incorrect (governments can print money, for example, so being unable to pay the debt at all is unlikely unless it is denominated in a foreign currency).  But if this is the strategy of the debt scolds -- cut services so we can run a surplus and then give out tax cuts -- then they don't care about the debt at all.  They just want to redistribute money in a different way across the economy. 

EDIT: Forgot to mention this is Joseph and not the regularly scheduled Mark content

Discipline then and now

[Originally posted at You Do the Math]

A few years ago I taught at a small rural school in the Mississippi Delta. The old timers would talk at great length about how much better the school had been before I got there. They attributed the decline to the closing of the alternative school. In the "good old days," any student who caused trouble would be pulled out of class and sent to a special, highly structured school -- basically a glorified study hall -- run by an honest-to-God former Marine drill sergeant.

According to the version I was told, the program worked exceptionally well but was shut down in a discrimination suit because a disproportionate number of African-American students were being sent to there. This was a very conservative community (I doubt that there was a unionized teacher in the county let alone in the school), so it is not surprising that this was seen as another instance of the federal government interfering.

As you might guess, I saw things a bit differently. The government has not only the right but the obligation to step in in cases of racial discrimination. Furthermore, even if there had not been a civil rights issue here, I still have very mixed feelings about policies that potentially denied certain kids a quality education simply because they were difficult to deal with.

There is, of course, another side to the debate. In a world of fixed resources, educators frequently have to weigh the needs of the many against the needs of the few. If a small group of students is undermining the quality of education for the student body as a whole, there is a case to be made for removing the students. Just as importantly, sometimes that particular disciplinary action is the best thing for the kid being disciplined. For some, the structure and discipline of a boot camp environment really is the best educational setting. For others, there is a scared-straight effect. For these kids, a brief stay in the alternative school is enough to convince them to improve their behavior and work habits.

There are a lot of lessons to be learned here, but for me, the big one is that education is filled with tough choices and difficult trade offs. We need to acknowledge this difficulty. We need to have honest, well thought out discussions about the consequences of discipline and expulsion (both nominal and de facto). In particular, if we decide to sacrifice one student for the good of the many, we need to own up to that decision.

Today, in many schools, we have covert policies in place (particularly in the popular "no excuses" schools) that effectively mimic the alternative school approach of that small Delta town, including having a disproportionate impact on African-American males (often taking it to the next degree). But as much as that troubles me, what bothers me even more is the fact that we don't face up to what we're doing.

Monday, October 20, 2014

Robert Heinlein's house of the future

I was doing some research on Heinlein for a post in the compensation thread and I happened on this article on the house he and his wife (an engineer) designed and built in the early Fifties. For Heinlein fans it's a chance to see another side of the man. For the rest of us, it's an interesting glimpse into the way futuristic used to look.

You can find the rest of the article here.

The myth of a data-driven Netflix

There's been a lot of talk about Netflix stock this week (usually with words like "plummet"), but a big part of the story has largely gone unnoticed, probably in part because it involves statistics.

As mentioned before, some aspects of the Netflix narrative such as the company building and HBO type content library, are simply, factually incorrect. Others, while not blatantly wrong, are difficult to reconcile with the facts.

One of the accepted truths of the Netflix narrative is that CEO Reed Hastings is obsessed with data and everything the company does is data driven (for example "What little Netflix has also shared about its programming strategy is that its every decision is guided by data."). The evidence in support of this belief is largely limited to a model that Netflix crowd sourced a few years ago and to endless assertions from executives at the company that they do know what they are doing despite evidence to the contrary.

Of course, all 21st century corporations are relatively data-driven. The fact that Netflix has large data sets on customer behavior does not set it apart, nor does the fact that it has occasionally made use of that data. Furthermore, we have extensive evidence that the company often makes less use of certain data then do most other competitors.

On pertinent case in point, particularly for the SEC, is churn rates.
But Netflix disagrees. “With respect to various operational metrics, management has evolved its use of these metrics as the business has evolved,” it wrote the SEC in response. Because it is so easy to quit and then restart a Netflix subscription, it said, “the churn metric is a less reliable measure of business performance, specifically consumer acceptance of the service.”
This is problematic on any number of levels. In terms of marketing, pricing and long-term corporate strategy, having a complete picture of how long people stay and why they leave is huge. The only excuse for not reporting churn would be if you had such a detailed picture of who was leaving and why that this additional metric was redundant.

In other words, Hasting should have a good, data-supported explanation for a recent sudden loss of subscribers.
Netflix CEO Reed Hastings blamed the subscriber drop-off on a $1 price increase the company instituted back this spring.

"Our best sense is it's an effect of our price increase back in May," Hastings said Wednesday night in an interview with CNBC. "With a little bit higher prices, you get a little bit fewer subscribers. So that's our sense of it. But we can't be 100% sure. We had so much benefit from Orange in Q2 and the early Q3, but that's what we think."
Phrases you don't want to hear in these circumstances include "our best sense" and "that's what we think." They convey the impression of a CEO who was blindsided by a bad day at the NASDAQ.

When contemplating a price increase, well-run companies look at the impact on retention and on acquisition. When Netflix management said
[M]anagement believes that in a largely fixed-cost streaming world with ease of cancellation and subsequent rejoin, net additions provides the most meaningful insight into our business performance and consumer acceptance of our service. The churn metric is a less relevant and reliable measure of business performance, and does not accurately reflect consumer acceptance of our service.
They were basically saying that losing one customer and gaining another is the same as keeping the same customer. That's a dangerous approach under the best of circumstances but it can be deadly when trying to gauge the impact of a pricing change.

Just to be clear, for years analysts and the SEC have been asking for more data, or at least more detailed statistics and Netflix has been saying "trust us, the aggregate number are good enough." Now the company appears to have screwed up badly, and they've done it in pretty much exactly the way you would expect a company to screw up when it doesn't drill down into the data.

p.s. I'm considering putting out a collection of business posts (something similar to the education reform e-book Things I Saw at the Counter-Reformation). Any thoughts or suggestions would be appreciated.

Friday, October 17, 2014

Hexagonal Reversi

Over at You Do the Math, I've got a post on a Reversi variant played on a 6x6x6 hexboard.

If you're feeling particularly nerdy, check it out.

Dick Cavett from 2013

I've been catching up on Cavett's NYT column. I have no idea how he pulls it off but he manages to constantly talk about his encounters with the iconic and yet he avoids being boastful or sycophantic. Here are some favorites:

Burton being Burton.

Laurel not being Stan.

and John Wayne being... hell, you wouldn't believe me anyway.

But it was a section near the end of this piece on Carson's rough start on the Tonight Show (Cavett got his start as a writer for the show) that caught my eye.

From Tonight, Tonight, Its World Is Full of Blight
By DICK CAVETT  MARCH 29, 2013 9:00 PM
If my friend Dave Letterman should decide next contract time that he’s sat through one too many starlet guests who come on to plug their movies, exhibit seemingly a yard of bare gam, pepper their speech with “likes” and “I’m like” and “awesome” and “oh, wow” and “amazing,” and list at least seven things they are “excited” about despite the evidence, from who knows what cause, of their half-mast eyelids, I’ll regret his going.

And speaking of Dave’s presumably stepping aside some sad day, if CBS is smart, there is in full view a self-evident successor to The Big L. of Indiana.

The man I’m thinking of has pulled off a miraculous, sustained feat, against all predictions — descendants of those same wise heads who foresaw a truncated run for the Carson boy — of making a smashing success while conducting his show for years with a dual personality. And I don’t mean Rush Limbaugh (success without personality).

I can testify, as can anyone who’s met him and seen him as himself, how much more there is to Stephen Colbert than the genius job he does in his “role” on “The Colbert Report.” Everything about him — as himself — qualifies him for that chair at the Ed Sullivan Theater that Letterman has so deftly and expertly warmed for so long. Colbert is, among other virtues, endowed with a first-rate mind, a great ad-lib wit, skilled comic movement and gesture, fine education, seemingly unlimited knowledge of affairs and events and, from delightful occasional evidence, those things called The Liberal Arts — I’ll bet you he could name the author of “Peregrine Pickle.” And on top of that largess of qualities (and I hope he won’t take me the wrong way here), good looks.

Should such a day come, don’t blow it, CBS.

"Velocitas Eradico," Nazi mad scientists and other cool things a little research would have uncovered

I know I'm being picky...

This article by Sam Biddle on the testing of a new weaponized railgun isn't bad. It does a good job explaining the physics and keeping the gee-whiz factor in check while acknowledging the genuinely exciting potential of the technology.

But I do have a complaint and it's one of the few times I'd actually favor a bit more gee-whiz. My problem with the article is that it is very much the story of one specific development -- albeit a cool and possibly important one -- and it doesn't show much interest in the history of the technology or its larger potential.

Here are some of the highlights from the Wikipedia entry:
[The Navy] gave the project the Latin motto "Velocitas Eradico", Latin for "I, [who am] speed, eradicate".
In 1944, during World War II, Joachim Hänsler of Germany's Ordnance Office built the first working railgun, and an electric anti-aircraft gun was proposed. By late 1944 enough theory had been worked out to allow the Luftwaffe's Flak Command to issue a specification, which demanded a muzzle velocity of 2,000 m/s (6,600 ft/s) and a projectile containing 0.5 kg (1.1 lb) of explosive. The guns were to be mounted in batteries of six firing twelve rounds per minute, and it was to fit existing 12.8 cm FlaK 40 mounts. It was never built. When details were discovered after the war it aroused much interest and a more detailed study was done, culminating with a 1947 report which concluded that it was theoretically feasible, but that each gun would need enough power to illuminate half of Chicago.
In 2003, Ian McNab outlined a plan to turn this idea into a realized technology. The accelerations involved are significantly stronger than human beings can handle. This system would be used only to launch sturdy materials, such as food, water, and fuel. Note that escape velocity under ideal circumstances (equator, mountain, heading east) is 10.735 km/s. The system would cost $528/kg, compared with $20,000/kg on the space shuttle.
I realize I complain about tech reporters getting carried away, but when something's this cool, it's OK to get a little more excited.

Sneetch class

James Kwak has a sharp and funny post on the economics and branding of first-class air travel.
Ultimately, what Suites Class is selling, along with every other “luxury” first-class cabin in the air, is a feeling of distinction. Air travel is a miserable experience for everyone involved, mitigated only by the immense convenience of being able to show up in another part of the world in a matter of hours. The glamour of high-end air travel, as with any other luxury good, is a function of exclusivity. Now that, thanks to Southwest Airlines, most people can afford to get on a plane, there have to be ways to pay more and more to get on the same plane. To get people to pay more, you have to give them something: an emotion, a brand, a story, something. And that’s why we have Suites Class.

Thursday, October 16, 2014

Education reform thoughts

This is Joseph.

I sent this article to Mark, but thought the blog might appreciate a few comments on it as well.  In particular, I was struck by the following passage:
We could double teachers' salaries. I'm not joking about that. The standard way that you make a profession a prestigious, desirable profession, is you pay people enough to make it attractive. The fact that that doesn't even enter the conversation tells you something about what's wrong with the conversation around these topics. I could see an argument that says it's just not worth it, that it would cost too much. The fact that nobody even asks the question tells me that people are only willing to consider cheap solutions. They're looking for easy answers, not hard answers.
In a really important way, this is the most compelling counter-point to the cries of urgency that accompany reform.  It's not that salary doubling is necessarily the solution, but that reformers appear to want cost-neutral or cost-saving improvements in quality. 

Now it is possible that such options exist.  It seems difficult to imagine extremely large effect sizes, as international comparisons don't seem to find obvious (cost neutral) options.  Do note that a longer school day without increasing salaries is an effective pay cut. 

Now, if there really is a crisis, why isn't the "pay more" option next to ideas like remove tenure?  Was that not the way we often respond to crises (think of the World Wars)?  Would increasing taxes to double salaries make it easier to remove (for example) tenure? 

Who knows.  But the Overton window here is pretty revealing. 

Non-compete agreements

This is Joseph.

Jimmy John's has a noncompete agreement.  Kevin Drum wonders what the point is, given how unlikely it is to be enforced.  Alison Griswold notes that:
That said, an unenforceable clause is still problematic if it's scaring employees who don't know any better into thinking they can't work at another sandwich shop—or another restaurant of any sort with a trade in sandwiches—for the next two years.
I don't even think that "scaring" is the right word.  Imagine the tight budgets somebody who works in fast food preparation likely has.  Yes, there will be exceptions.  But is it obvious that there will be lawsuits, even in a place like California

Do you know what no company wants to do with the new sandwich person?  Litigate to keep them.  Nor does an employee want to spend time and money in court to defend themselves if the court should grant an injunction while they hear the case.  Courts are slow, sessions happen during paid workdays, and it's not at all clear that anybody wants to deal with that while no longer making money.

So I think the chilling effect might be more than one realizes. 

Wednesday, October 15, 2014

Assuming I didn't lose you at "TED Talk"

I need to do more research before I wade into this (or convince Joseph to do it for me), but even with the 10 to 50 year wiggle room, talk of having absolutely total confidence makes me nervous.

[GUY] RAZ: Which they did, an amazing scientific feat. They mapped the code that makes up all human DNA. Now they're still trying to figure out what it means, but they already know what it could mean for the future.


RESNICK: The world has completely changed and none of you know about it.

RAZ: So how is it going to change the world?

RESNICK: In a bunch of ways. The good news is it's going to help us immensely in treating cancer 'cause cancer is nothing more than a disease of the genome. It's a disease where one cell has certain changes, which cause it to get a little bit worse and then it reproduces. And by the time you've got a solid tumor, you've got this really heterogeneous population of cancerous cells. And if you sequence their genomes, they're a mess. And so right now, prior to genome sequencing, we're taking wild guesses at what the molecular basis of one's cancer is. And now going forward, what we're going to do is say, forget all of that, what is happening at the molecular level because this drug can target only those cancers that have the BRAF mutation, as an example.

RAZ: So where is it headed? What can you imagine in 10 or 20 years or beyond?

RESNICK: I think we will cure cancer. Genomics and sequencing at large will ultimately cure cancer. Whether that happens in 10 years or 50 years or more is difficult to say.

RAZ: That's incredible. I mean, you can say that with total confidence?

RESNICK: Absolutely. At some point, we'll snuff it out. I mean, people will still develop cancer, certainly, unless we get into genetic engineering of humans, which is something we ought to talk about, but it will be curable.

Two Quotes

From Salon recently:
“It’s not really about asking for a raise, but knowing and having faith that the system will give you the right raise,” [Microsoft CEO Satya] Nadella said in conversation with Dr. Maria Klawe, a member of the Microsoft Board, Harvey Mudd College president and computer scientist.

“That might be one of the initial ‘super powers,’ that quite frankly, women (who) don’t ask for a raise have,” stated to Klawe. “It’s good karma. It will come back.

And from Marketplace last year:
Sarah Lacy, founder of tech news site Pando Daily* ... said the BART strike exacerbated what she sees as a philosophical divide in the Bay Area. “People in the tech industry feel like life is a meritocracy. You work really hard, you build something and you create something, which is sort of directly opposite to unions.” 

Both the tech and financial sector have embraced the idea that economic rewards are directly correlated to work and worth. It's a strange mixture of efficient market theorem and social Darwinism, often with more than a bit of Randianism. I suspect that Nadella and Lacy have so internalized this worldview that they no longer have any idea how they sound to the general public.

* To those of you following the pension scandals: yeah, that Pando.

Tuesday, October 14, 2014

Effect sizes: an often overlooked issue

This is a post by Joseph

Brad DeLong makes an argument that fits very well with a long running discussion that Mark and I have had.  Just because there is a known relation, doesn't mean that the effect size of the elements can be ignored.  So, the existence of the Laffer curve is pretty much certain, but the exact inflection point where the curve shift from more revenue to less revenue is very, very important. 

Brad Delong compares current arguments for infrastructure to the Laffer curve:
In a world where the real rate at which the U.S. Treasury can borrow for ten years is 0.3%/year and in which the tax rate t is about 30%, infrastructure investment fails to be self-financing only when the comprehensive rate of return is less than 1%/year.

Now you can make that argument that properly-understood the comprehensive rate of return is less than 1%/year. Indeed, Ludger Schuknecht made such arguments last Saturday. He did so eloquently and thoughtfully in the deep windowless basements of the Marriott Marquis Hotel in Washington DC at a panel I was on.

But Mankiw doesn’t make that argument.

And because he doesn’t, he doesn’t let his readers see that there is a huge and asymmetric difference between:
my argument that tax-rate cuts are not (usually) self financing, which at a tax rate t=30% requires only that α < 2.33; and:

his argument that infrastructure investment is not self-financing, which at a tax rate t=30% requires that ρ < 1%/year.

To argue that α < 2.33 is very easy. To argue that ρ < 1%/year is very hard. So how does Mankiw pretend to his readers that the two arguments are equivalent? By offering his readers no numbers at all.
This principle is broadly applicable to all sorts of arguments that come up on this blog.  For example, getting rid of a marginal bad teacher is probably efficient.  But constantly churning teachers might shift the efficiency function to a different place on the curve. 

So realistic estimates of parameters are critical but also they can also be hard.  How do you really tell the Comprehensive rate of return of infrastructure?  Is it different in Detroit versus San Francisco?  Can it be reliably estimated in advance or only known historically.

But it does lead to better arguments when transparent estimates (that can be discussed or tested) are placed out where they can be evaluated. 

Selection on Spinach*

[I have the nagging feeling that I'm not using the proper terminology with the following but the underlying concepts should be clear enough. At least for a blog post.]

Let's talk about three levels of selection effects :

The first is initial selection. At this level, certain traits of potential subjects influence the likelihood of their being included in the study. If you ask for volunteers in person, you will end up underrepresenting shy people. If you use mail surveys, you will underrepresent the homeless:

The second level comes after a study starts. You will frequently lose subjects over time. This type of selection is particularly dangerous because you cannot assume that the likelihood of dropping out is independent of the target variable. The isue comes up all the time in medical studies. For serious conditions, a turn for the worse can make it extremely difficult to continue treatment. The result is that the people who stick around till the end of the study are far more likely to be those who were getting better;

(Up until now, the types of selection bias we have discussed, though potentially serious, are generally not deliberate. Their consequences are unpredictable and they happen to even the best and most conscientious of researchers. That is no longer the case with level three.)

The third level concerns attempts to manipulate attrition so as to affect the results of a study. In these cases, researchers will attempt to get rid of those subjects who are likely to drag down the average. This is blatant data cooking and it can be remarkably effective. In school administration, the term of art is "counseling out." It is shockingly widespread, particularly among the "no excuses" charter schools.

The effect of this practice on kids can be brutal but that is a topic for another post. What interests us here are the statistical concerns; what are the analytic implications of this policy? In terms of direction, the answer is simple: schools that engage in these policies will see their test scores artificially inflated. In terms of magnitude, there is really no telling. The potential for distortion here is huge, particularly when you take into account the possibility of peer effects.

Put bluntly, in cases like this, "The first Success graduating class, for example, had just 32 students. When they started first grade in August 2006, those pupils were among 73 enrolled at the school," data showing above-average results are almost meaningless.

[A few weeks ago, I put out a collection of our early posts on education (Things I Saw at the Counter-Reformation).  The impact of attrition is one of the big running themes.]

*Spinach being, in this case, a substance that greatly increases the power of a given effect.

Monday, October 13, 2014

XKCD -- write your own damned post

I've got at least two pieces I'd like write around this: one discussing the way we approach AI research (and the innate limitations in that favored approach); the other a rant about how ddulite journalists fail to catch the important subtleties in technology.

I'm sure there are more angles here so I'll throw this one out to the room. What are the examples of a slight change taking a problem from easy to nearly impossible?

Friday, October 10, 2014

Checking in with -- the website that's better than it has an right to be

Even more than Mental Floss, has taken the worst genre in journalism (the unfortunately named listicle) and made it something entertaining, informative and intelligent. I don't drop by that often because it's such a time sink, but when I do I always come away with something worth sharing.

For instance, 5 Dirty Tricks Apple Uses to Get You to Buy a New iPhone opens with this nice example of a deceptive graphic:

The problem is that the old version (on the left) is misleadingly shot in a different light: it doesn't have any shadowed black edge and is a completely silver shade, whereas the iPhone 6 and 6 Plus are cleverly shaded at the sides to make them appear skinnier than they actually are. Here's a handy GIF to show what we mean:

I'm not crazy about the animation, but still.

The article goes where so few technology writers dare and actually discusses the functionality from a common sense perspective.
Think about what you do with your phone -- send texts, make calls, check social media, play terrible games, and send immediately regrettable photographs to people you just met. Unless you're a professional photographer, you're not going to care about how much the camera has improved on the iPhone 6 (and if you are a professional photographer, you probably take pictures on something better than a goddamn iPhone). And for those of you who game -- nothing playable on the iPhone really needs a huge upgrade in power. Just look what happened when they tried to sell Angry Birds on actual gaming systems. So what do we need the better specs for? To have more apps? Not according to the hard numbers.

In 6 BS News Stories That Went Viral: The Girl With Three Boobs, they gleefully point out how gullible journalists can be when there's a deadline.
That's Telegraph, The Hollywood Reporter, E! Online, Huffington Post, and International Business Times reminding us that, like the ocean, the Internet is a vast chilly abyss that cradles unspeakable wonder as well as waking nightmares. We'll leave you to decide which category triple boobs fall under, because we honestly have no idea.

For those of you wondering if this means Martian mind-vacations are just around the corner, it shockingly turns out there are a few things off about this story. Like the fact that the woman has refused to name any of the doctors involved, won't show her new gift to the world for more than a quick few seconds up close, or that she once filed a missing baggage claim listing "3 breast prosthesis" as one of the stolen items. Also relevant? She once apparently described herself as a "provider of Internet hoaxes since 2014."

4 Reasons Movie Special FX Are Actually Getting Worse has an excellent discussion of the paradoxical economics of CGI,

It turns out that making the most visually spectacular images that the human brain can comprehend requires a good bit of scratch. That's why huge-budget blockbusters have been becoming the norm (33 of the 50 most expensive movies of all time have been made in the last four years); studios are so preoccupied pouring hundreds of millions of dollars into CGI for schlock like Battleship because they could, that they didn't bother to stop to think if they should.

And, as CGI continues to improve, movies only become more reliant on it. We've mentioned before how Rhythm & Hues, the visual effects company most famous for bringing to life all the Oscar-winning, pants-shitting fear of sharing a Tunnel of Love rowboat with a 400-pound marvel of evisceration and death in Life of Pi, went bankrupt because they did their job too well.

Meanwhile, the studios are pumping more and more money into already-bloated special effects budgets (it sure as shit isn't going toward better screenplays). For Transformers: Thing of Whatever, Industrial Light & Magic spent about 15 weeks per Transformer just getting the basic model ready, and each model has about 10,000 parts -- that's not a joke, that's seriously how many individual pieces there are in Michael Bay's idea of a talking truck. The company had to start making models six months before filming even started, just to meet the production schedule. And remember, ILM is like the GE of special effects studios, so if they're balls-to-the-wall to make their effects look good in a profitable fashion, what chance does a scrappy, upstart VFX company have?

Finally, 3 Artists Who Got Screwed for Creating Iconic Characters is a perfect complement to the Kirby thread, reminding us that, like many industries based on creativity, little of the money from comics goes to those who do the actual creating.

Thursday, October 9, 2014

Step-back SAT/GRE problems -- trying something new at "You Do the Math"

I've been thinking about the problem of adapting lessons for different media in general and for video in particular. There is a popular but wildly misguided impression that you can create an effective video by just sticking a camera in front of a live presentation. Teaching live is an interactive process. Even when the students don't say a word, the good teacher is alert to the class's reactions. You speed up, slow down, offer words of encouragement, come up with new examples and occasionally stop what you're doing and go back and reteach a previous section.

With a video lesson you set the course then you leave the room. What's worse, it's a really big room and many if not most of the kids are there because the standard methods of instruction have not served them well.

One idea I'm playing with is thinking of the problems in terms of a graph (as in graph theory, not data visualization) where the path is determined by how well the student is doing. As a start in that direction I'm playing around with paired problems -- if you are confused by the first (more difficult) problem there an easier one to try -- and I've got the first couple up at the teaching blog.

Here's the medium problem:

Circle 1

The radius of circle 1 is 5. Both line segments pass through the center of the circle. Find the area of the shaded region.

You can find the answer and explanation at You Do the Math. Feedback is always appreciated.

The New York Times' regularly scheduled sackcloth and ashes show

From Talking Points Memo:
When New York Times columnist David Brooks revealed last month that his son is serving in the Israeli military, plenty of questions followed: Should Brooks have been more open about that fact? Should it preclude him from writing about Israel? Is it any different from a columnist with a child serving in the U.S. military?

We learned Wednesday that the revelation has even brought about a minor disagreement between two Times editors.

The paper's public editor Margaret Sullivan wrote Wednesday that while she "strongly" disagrees with the suggestion that Brooks "should no longer write about Israel," she also believes that "a one-time acknowledgement of this situation in print (not in an interview with another publication) is completely reasonable."

"This information is germane; and readers deserve to learn about it in the same place that his columns appear," Sullivan wrote.

That's not how Times editorial page editor Andrew Rosenthal sees it though. Rosenthal told Sullivan that the columnist shouldn't have been required to note that his 23-year-old son enlisted in the Israel Defense Forces.

"I do not think he ever had an obligation to say that his son made this choice, any more than if his son had joined the U.S. Air Force (although I recognize that Israel is more controversial in some people’s minds)," Rosenthal said.
Just to be clear, we're talking about David Brooks. You know the guy, quotes discredited studies, makes stuff up. Over the years, he has given critics a steady stream of material, truly unambiguous examples of factual mistakes and substantial omissions in service of the narrative of the moment. His editors have been remarkably quiet on these errors (which is about par for the NYT course)

The New York Times does frequently engage in very public displays of repentance and self-examination. They admit to professional and ethical lapses. They debate in very serious tones the finer points of journalistic conduct.  Almost invariably, however, they pick the most minor of lapses to focus on. It is almost as if they wanted to appear conscientious about their profession without actually doing the hard work or accepting the consequences.

Wednesday, October 8, 2014

XKCD Marriage

Lots of interesting implications here, but they'll have to wait till later.

“I can no longer accept cash in bags in a Pizza Hut parking lot” -- time to add Pennsylvania to the list

In an article entitled READING, WRITING, RANSACKING, Charles P. Pierce makes me think that I haven't been spending nearly enough time looking at education reform in the Keystone State. The quote from the title comes Pierce's account of the federal investigation of former Pennsylvania Cyber Charter School leader Nick Trombetta:
The bags of cash, a private plane bough by Avanti but used mostly by Trombetta, a Florida vacation home and a home in Mingo Junction, Ohio, for Trombetta’s former girlfriend all were described as perks enjoyed by Trombetta as part of a scheme to siphon money from taxpayers’ funds sent to PA Cyber for more than four years.
The case is actually small time compared to the other scandals going on in the state, but you have to admit it's a great quote.

A bigger and much more familiar scandal is the lack of accountability:
For reasons that aren't clear, millions of dollars have moved between the network of charter schools, their parent nonprofit and two property-management entities. The School District is charged with overseeing city charters, but "does not have the power or access to the financial records of the parent organization," according to District spokesperson Fernando Gallard. "We cannot conduct even limited financial audits of the parent organization." That's despite the fact that charters account for 30 percent of the District's 2013-'14 budget. Aspira declined to comment. The $3.3 million that the four brick-and-mortar charters apparently have loaned to Aspira are in addition to $1.5 million in lease payments to Aspira and Aspira-controlled property-management entities ACE and ACE/Dougherty, and $6.3 million in administrative fees paid to Aspira in 2012. 
Add to that some extraordinarily nasty state politics involving approval-challenged Pennsylvania governor Tom Corbett, the state-run Philadelphia School Reform Commission (which has a history of making teachers' lives difficult basically for the fun of it) and a rather suspicious poll:
"With Governor Corbett's weak job approval, re-elect and ballot support numbers, the current Philadelphia school crisis presents an opportunity for the Governor to wedge the electorate on an issue that is favorable to him," the poll concludes. "Staging this battle presents Corbett with an opportunity to coalesce his base, focus on a key emerging issue in the state, and campaign against an 'enemy' that's going to aggressively oppose him in '14 in any case."
I don't know enough about Pennsylvania politics to competently summarize this, let alone intelligently comment on it but it's difficult to imagine an interpretation that makes things looks good.

Tuesday, October 7, 2014

Now they've got me defending the efficient market theorem...

I know it's trivial, but this one has always annoyed me.

There are cases where the conventional wisdom is so screwed up that the market reads bad news as good news and rewards stupidity, but otherwise, in a reasonably efficient market, stocks only go up when bad news beats expectations if they had already gone down as the expectations had rolled in. They are, in other words, making up some of the lost ground. Financial reporters love the "went up on bad news" story but they almost invariably fail to mention how the stock had been doing before.

Don't get me wrong. I'm still not a fan of the EMT, but on this one, at least, I'm willing to give them a pass.

Monday, October 6, 2014

I'm going to let someone else bitch about the New York Times for a while

Besides, when itt comes to take-downs of bad financial journalism, there's no one sharper than Felix Salmon.

In "Annals of NYT innumeracy, Bank Rossiya edition," Salmon takes apart a recent article entitled “It Pays to be Putin’s Friend.” No doubt the basic premise is true, but the examples described by the NYT don't support the point at all. Salmon points out lots of sloppiness in the piece but this is arguably the money shot.
So [Sergei P.] Roldugin took out a loan, of unknown size, to buy a stake of 3.2% in Bank Rossiya. How on earth does that make him worth anywhere near $350 million?

And here the light slowly dawns — the NYT has taken the sum total of Bank Rossiya’s assets, and used that number as the the value of the bank itself. ($350 million, you see, is 3.2% of $11 billion.)

Of course you can’t value a bank by just looking at its assets, you first need to subtract its liabilities. The NYT story leads with “State corporations, local governments and even the Black Sea Fleet in Crimea” moving their bank accounts to Bank Rossiya — all of those deposits are liabilities of the bank, which need to be subtracted from its assets before you can even begin to arrive at an overall valuation for the bank itself. Just looking at the assets, without looking at the liabilities, is a bit like scoring a sports game by looking only at the points scored by one team.

Probably, most of the value in Bank Rossiya is to be found in the commodity and media assets which it seems to have been able to acquire on the cheap. (The bank itself, qua bank, might well be worth nothing at all.) And no one’s going to find out the true value of those assets by looking at the official size of Bank Rossiya’s balance sheet. It seems to me, indeed, that Bank Rossiya is in large part being used as a holding company, a reasonably safe place where Vladimir Putin’s billionaire friends can keep some of the valuable assets they’ve managed to acquire over the years. I’m just guessing here, but I doubt they have any particular desire to share 3.2% of those assets with some random cellist [Roldugin]. To simply take the official size of Rossiya’s balance sheet, and declare it to be the value of the bank: that’s just bonkers.

Friday, October 3, 2014

Examining the rope – – Rotten Tomatoes edition

[You can find the origin of the metaphor here]

Our last Rotten Tomatoes post may have come out a little harsher than I intended. I probably focused too much on the specific glitch and not enough on the larger point, namely that metrics almost never entirely capture what they claim to. Identifying and fixing problems is important, but we also have to acknowledge our imitations.

If we are stuck with imperfections then we will just have to learn to live with them. A big part of that is trying to figure out when our metrics can be relied upon and when they are likely to blowup in our faces.

Let's take Rotten Tomatoes for example. In many ways, the website provides an excellent tool for quantitatively measuring the critical reaction to a movie. It is broad-based, consistent, and as objective as we can reasonably hope for.

But is it the best possible measure in all conceivable circumstances? If not, when does it break down?

When you see a 60% fresh rating that means that 60% of the reviews examined were considered positive. You will notice that is a binary variable. The most enthusiastic of reviews is put in the same category as the mildly favorable. The inevitable result is that sometimes a film will rank lower on this binary average then it would have on a straight average of star rankings.

Just to be clear, there are some definite advantages to this yes/no approach. As anyone who has dealt with satisfaction scales knows, you can get into all sorts of trouble making interval assumptions about that one through five.

 Can knowing their binary foundation help us make better use of the Rotten Tomatoes scores?

If we can make certain assumptions about the distribution of scores, we can tell a lot about which films are likely to be favored. Keep in mind that a good review counts the same as a great one. Therefore a film that is liked by everybody will do better than a film that is loved by most but leaves a few indifferent or hostile.

Without getting into relative merits (all are great films), consider Philadelphia Story and the big three from  Martin Scorsese, Taxi Driver/Raging Bull/Goodfellas. By many measures, such as the influential Sight & Sound poll (according to Ebert "by far the most respected of the countless polls of great movies--the only one most serious movie people take seriously."), all three Scorsese pictures are among the most critically hailed movies ever. All three have very good scores on the "Tomatometer" but none have a perfect score. The same goes for films like Bonnie and Clyde, The Magnificent Ambersons, and Bicycle Thieves.

Philadelphia Story, on the other hand, is much less likely to get nominated as greatest film ever, but it is a movie that virtually everyone likes. It's an excellent film, skillfully directed, starring three of the most charming actors ever to come out of Hollywood. Not surprisingly, it has a perfect score on Rotten Tomatoes.

This is not to say that Sight & Sound is better than Rotten Tomatoes. Every scoring system is arbitrary, sometimes plays favorites and never exactly captures what we expect it to measure.  The lesson here is that, if you want to use a metric in an argument, you need to know how that metric was derived and what its strengths and weaknesses. You can't find a perfect metric but you can have a pretty good idea where the imperfections are.

Thursday, October 2, 2014

Understanding Common Core-aligned math homework

I volunteer a couple of times a week with a group that does after school tutoring for urban students in LA. My role is "math floater." I walk around the room and help the kids, and sometimes the tutors, with math problems. When the kids ask for help, it's usually just your basic math question, but when the tutors ask for help it's often less about the math and more about the unfamiliar approach the assignment takes to solving a familiar problem.

This is perhaps most exasperating for those tutors with math backgrounds. You can imagine what it must be like to have a degree in engineering and yet be stumped by an eighth-grader's pre-algebra homework. Of course, it's not the math that's throwing them; it's all the weird and arbitrary steps that have been layered onto the math.

After struggling a bit myself, I realized that the key was to approach these problems as bad translations of unknown texts. If I looked hard enough, I could usually find an antecedent, a good lesson (something I had read in Pólya or seen demonstrated by a master teacher or used with success in one of my classes) that had somehow devolved into the misshapen thing sitting in front of the student.

Recently, I ducked into the tutoring center when I wasn't scheduled to work. I just stepped in to use the bathroom but before I got across the room, I heard a couple of tutors calling my name. They were struggling with a third or fourth grade problem where the student had to perform a number of steps including filling out a three by three grid in order to find the product of two three-digit numbers. The answer kept coming out wrong and none of the tutors could figure out why since none of them were sure how the process was supposed to go.

The point of the question was to illustrate the distributive property. Handled properly, the general format could have made for a pretty good problem. As was it was a disaster. Developmentally inappropriate, badly explained, overly long (two-digit numbers would have made the point just as well), devoid of relevant context. Like a bad translation of a bad translation of a good problem. That got me wondering if perhaps the process for coming up these problems worked something like this...

Wednesday, October 1, 2014

Two ways of looking at the achievement gap and how the reform debate often misses them both

The following came out of a phone conversation I had this weekend with Joseph. I'll need to get back to this later but for now here's a thumbnail version just to have something on the record.

When we talk about the achievement gap in education, there are two distinct but valid ways of approaching the question:

The first is in terms of variability. The people in the bottom quartile are, by most measures, getting a much worse education than the remaining three quarters of the population;

The second involves correlation. People in that bottom quartile are disproportionately likely to be poor, to be black or Hispanic, or to speak English as a second language.

You address the first by raising scores for those at the bottom. You address the second by changing the order. Reducing the gap is still desirable regardless of the definition used -- we don't want any of our schools to be bad nor do we want an education system that entrenches the class system -- and there are many things we can do that will improve both, but it is important to remember that we are talking about two distinct objectives.

To further complicate the picture, proposals that are meant to improve educational outcomes in general are often pitched as ways to address the achievement gap.

All three goals (improving overall outcomes, reducing variability and breaking the correlation) are important -- I'd argue the third one is absolutely vital -- but whenever we need to be clear about what we are trying to do.

Limits of Market Forces: a never-ending saga

This is a post by Joseph.

I was reading this article and was struck by this passage:

Poole lamented in his blueprint that the country was still not ready in 1980, and he warned his policymaker readers to expect resistance at the local level if they tried to push through programs transferring the costs for criminal justice (and policing) from general taxpayers to “users.” But one thing that Poole and Reason are very proud of is how they brought ideas from the fringes to the mainstream — and Ferguson is a prime example of how Poole’s neoliberal blueprints on privatizing criminal justice were eventually adopted in cities across the country

In Ferguson’s offender-fee system, city revenues from traffic fines make up 21% of the city budget and continue soaring. Those revenues are squeezed mostly from black drivers — 86% of motorists stopped in Ferguson are African-American, well above their 63% portion of the town’s population.
There are two pieces that I think need to be very carefully thought about.  First, as a matter of history, making criminal charges a means of raising revenue has been associated with the worst excesses of tyranny.  Think of the issues of High Treason and attainder during the War of the Roses and Tudor era in England.  Does anybody think the ability to seize people's property made these excesses better but reducing taxes (for example)?  So this is not an inevitable property of these systems, but it is worth thinking about carefully when implementation is being considered.

Second, market forces work best when the costs are borne by those for whom the service is provided to.  Here we need to be very tricky -- policing and trials are not usually services that criminals want provided to them  -- instead it may be a cost of doing business to them.  Nor do they have much influence in setting costs or process.  Instead, the service is provided to all of the non-criminals, who are made safer by the policing. 

So if we fund the system by charging criminals, we inherently break a key feedback loop of market forces.  Criminals cannot, for example, pick their judge or arresting officer.  Nor due we seek to compensate "users" who are incarcerated by mistake, but in other venues billing errors are routinely addressed. 

Instead, I would argue a fair justice system has market value.  A predictable legal environment and a good set of laws makes it easier for business to function efficiently and to invest in the future.  That is a public good, as much as clean air or automobile capable roads are. 

The Thirty Million Words Initiative

This is interesting [if you get a chance, listen to the audio at the link]

“By the end of the age of three, children who are born into poverty will have heard 30 million fewer words than their more affluent peers,” says Dr. Dana Suskind [A pediatric otolaryngologist at University of Chicago -- MP].

Dr. Dana Suskind is the director of the Thirty Million Words initiative – an education and research program out of Chicago.


The moment a baby is born their brain is already beginning to develop. That is why these early language interactions are so crucial. Scientists can actually measure the word gap or the number of words spoken at home. They use a little device called the LENA which stands for language environment analysis.

The LENA is about the size of a credit card. Babies wear it at chest level. Not only does it count or record words, it can also analyze what it records. The LENA is able to differentiate all the different kinds of sounds that are heard in a baby’s environment. One way to think of the LENA is that it’s like a language pedometer.

“So just like a regular pedometer counts the number of steps you take in a day the LENA counts the number of words a child is exposed to and how many conversations they have with their caregiver or parent,” Suskind says.

It’s not just the number of words spoken to babies but the quality of words spoken. Dr. Adriana Weisleder, a developmental psychologist who is an associate project director and co-investigator at the BELLE project says that, “in some families a lot of the speech to children is what they called business talk. The function of the speech is to get the child to do something right so they’re commands or imperatives. That happens in all families. It has to happen, right? Parents have to get their kids to do things. But when a high proportion of the speech that children hear is composed of those kinds of business talk or imperatives then that means they’re not getting a lot of the other rich talk and conversation.”

Still a device like the LENA can’t close the word gap all by itself.

“Just like a pedometer will not change the obesity and health crisis in the country, we can’t put everything on a piece of technology,” Suskind says.

One way Dr. Suskind’s Thirty Million Words initiative tries to close to gap is by actually going into homes. On top of going over the results from lena recordings – Thirty Million Words has created a curriculum for parents. It includes videos modeling ways caregivers should talk to their baby.

Families that speak more than one language at home can face a special challenge: what language should they speak to their kids in?

“It’s not just a moral and right thing, but the science is clear that parents and caregivers should be talking and interacting with their children in their native language. It does no good to be speaking in a language you don’t feel comfortable with,” Suskind says.

“Having a higher vocabulary even if it’s in Spanish still makes kids be more prepared for school.” Weisleder says.

Why is that? talking a lot to your child is about more than just teaching them words – it’s helping them understand basic concepts.

”If you know in spanish the words for horse and dog and house and barn. You know those words in spanish but you also know a lot of relationships between those things. You know that dogs and horses are animals and that a lot of dogs live in houses and horses might live in barns, lots of the different things.”

Bridging the word gap is not about getting babies ready to read Don Quixote by the age of four – it’s about setting up the building blocks so that children can be ready learn more easily once they get to school.