Sunday, March 31, 2013

This guy REALLY doesn't like MOOCs

The guy in question is Jonathan Rees. He's a history professor at Colorado State and his blog, More or Less Bunk (which I recently came across by way of Lawyers, Guns and Money), seems to be all MOOC, all of the time. I don't agree with all of his points, but he does make some good ones and given the embarrassingly low thought-to-hype ratio we normally encounter on the subject, posts like “My MOOC is a pale imitation of the class I teach on campus.” provide some badly needed balance.

Weekend blogging -- 61 seconds from the world's most prolific film composer

If the whip cracks don't give it away, you're not watching enough movies.

* At least among major players, I dare you to find an IMDB page to compare to this one.

A few brief thoughts on Timothy Noah's reaction to the firing of Timothy Noah

I didn't really have any strong feeling about the firing of Timothy Noah, but when I came across this Politico excerpt in Talking Points Memo, it seemed rather odd to me.
“Once, shortly after he bought it, he said he liked a piece I'd written advocating an energy tax,” Noah wrote. “Another time, after I wrote a piece about Jim DeMint's departure from the Senate headlined 'Requiem For A Wingnut,' he emailed me to say ... wait, I've got it here: ‘I have little esteem for Jim DeMint, but I also want us to make a rule of not name-calling in headlines. We have strong opinions, but name-calling so outrightly undermines the seriousness of what we are trying to do here.’”

“I quietly changed the headline to the somewhat clumsy, ‘Farewell, Filibusteringest Senator’ and quietly worried whether the magazine's new owner (who around that time also told an audience at the Kennedy School that he'd like to co-brand a chain of cafes called the New Republic) might be a young man with more money than sense,” he said.

And, he added, “my firing is an additional data point.”
I've read this over a few times and it still seems a bit strange. A publisher told a writer to tone down a title. There was nothing particularly special about the title and the the publisher gave a reasonably sounding explanation for why he wanted the change. This bothered the writer enough to cause him to worry about the publisher's competence and to later use it as the basis of a very public criticism.

I realize that Noah may be understandably angry, but even factoring that in there seems to be a weird disconnect here, as if, when he tells me that a publisher changed one of his titles, he expects me to conclude that there's something wrong with the publisher. It's not immediately clear to me that the publisher was wrong, either about this particular title or about the policy of avoiding taking shots in a title, but even if the publisher were clearly wrong, it would still strike me as part of the normal friction of putting out a magazine.

I also get the feeling that Mackenzie Weinger, the author of the Politico piece, had the same reaction as Noah, especially given the snark about the New Republic cafes. (two quick points: first, speakers at events like this are expected to toss out big, interesting, out-of-the-box ideas like co-branding seemingly unrelated businesses; second, weird co-branding ideas are common. By the standards of the field and in the context of the speech, this suggestion wasn't particularly outrageous.)

What makes this more interesting than just than just another case of an ex-employee griping about a former boss is the way it supplies what Noah might call an additional data point for some ongoing concerns about the state of journalism, the idea that the profession has a problem with arrogance and tribalism.

To the tribalism point, this is the second time in recent memory when Politico's Media column has uncritically taken the side of Washington journalistic insiders (such as Noah) against outsider (such as Hughes). It was the Media column where Dylan Byers went after Nate Silver because, to be blunt, he was making the the DC journalism insiders look bad and, more to the point, expendable.

And having journalism critics who uncritically take the side of other journalists is not a good thing.

Friday, March 29, 2013

Do the connotations of "property" influence the "intellectual property" debate?

Tim Taylor has a great post on the history of the term "intellectual property" and the way wording may be shaping our thinking. (via Thoma)
Mark Lemley offers a more detailed unpacking of the concept of "intellectual property" in a 2005 article he wrote for the Texas Law Review called "Property, Intellectual Property, and Free Riding" Lemley writes: ""My worry is that the rhetoric of property has a clear meaning in the minds of courts, lawyers and commentators as “things that are owned by persons,” and that fixed meaning will make all too tempting to fall into the trap of treating intellectual property just like “other” forms of property. Further, it is all too common to assume that because something is property, only private and not public rights are implicated. Given the fundamental differences in the economics of real property and intellectual property, the use of the property label is simply too likely to mislead."

As Lemley emphasizes, intellectual property is better thought of as a kind of subsidy to encourage innovation--although the subsidy is paid in the form of higher prices by consumers rather than as tax collected from consumers and then spent by the government. A firm with a patent is able to charge more to consumers, because of the lack of competition, and thus earn higher profits. There is reasonably broad agreement among economists that it makes sense for society to subsidize innovation in certain ways, because innovators have a hard time capturing the social benefits they provide in terms of greater economic growth and a higher standard of living, so without some subsidy to innovation, it may well be underprovided.

But even if you buy that argument, there is room for considerable discussion of the most appropriate ways to subsidize innovation. How long should a patent be? Should the length or type of patent protection differ by industry? How fiercely or broadly should it be enforced by courts? In what ways might U.S. patent law be adapted based on experiences and practices in other major innovating nations like Japan or Germany? What is the role of direct government subsidies for innovation in the form of government-sponsored research and development? What about the role of indirect government subsidies for innovation in the form of tax breaks for firms that do research and development, or in the form of support for science, technology, and engineering education? Should trade secret protection be stronger, and patent protection be weaker, or vice versa?

These are all legitimate questions about the specific form and size of the subsidy that we provide to innovation. None of the questions about "intellectual property" can be answered yelling "it's my property."
You could go further and argue that copyrights and patents actually restrict property rights. since they limit what people can make and sell. This aspect has caused some notable libertarians to voice concerns about the seemingly inexorable expansion of these government-granted monopolies.

Some similar issues are raised by the different meanings of the term "rational." "Rational" means something very specific when used in the context of economics. All sorts of behavior we would normally consider rational is irrational in the economics sense. Unfortunately, some economists have used the negative connotation we associate with "irrationality" in its general usage to argue against decisions that are irrational only in the strict technical sense..

Some people just insist on being tied to their possessions

Joseph appears to have had somewhat mixed feelings about this New York Times piece by Graham Hill, a multi-millionaire preaching the freedom of not getting tied down by your possessions. Joseph wondered how this philosophy might work for people on the other end of the spectrum

Assuming things haven't changed greatly since 2003, you can probably get a pretty good idea from this LA Times story from Carla Rivera about a service that provided storage bins for the homeless:
At 7:45 on a recent morning, the nondescript building looked as busy as a checkroom at an airport or train station, with a line of people hauling backpacks, duffle bags and grocery carts.

Chris Thorn, 47, was sorting through a brown leather satchel on rollers, pulling out thick sweaters and other winter clothing to store in anticipation of warmer weather.

Thorn said she has been homeless for a year and has been staying at the Midnight Mission, where there is limited space for belongings.

"It's especially important to have someplace to store clothes for when you get a job," said Thorn, who says she occasionally does painting and construction work.

Nearby, Ruby Simmons, 61, struggled to maneuver a grocery cart overflowing with blankets, sofa pillows, purses, comforters, books, toiletries, an umbrella and a knob-ended, sturdy stick that she said is useful for walking or protection.

Even after filling a bin, Simmons had a cart full of blankets, clothing and her westerns and mystery novels to keep with her.

Simmons was nonplused when asked what she considered the most important of her belongings, some of which she has had since moving from Missouri more than 30 years ago.

"I got the pillows from a minister who was giving stuff away. You'd hate to lose any of it," said Simmons, who has been homeless off and on for years and was recently living on the street. She said she hopes that, in another year, when she reaches retirement age, Social Security will provide enough for a hotel room or apartment.

Graham Hill

I have some aspirations to be a bit of a minimalist.  But I was struck by the New York Times piece by Graham Hill.  In it, a multi-millionaire talks about how he was able to live a life of freedom wandering around the globe and how possessions were a chain.  The correct response to this piece is to ask how it would have worked out if he had decided that his cash assets were also a fetter

Based on anecdotal evidence from talking to homeless people, I suspect it would not have been fantastic.  Consider this episode:

But I was just going along, starting some start-ups that never quite started up when I met Olga, an Andorran beauty, and fell hard. My relationship with stuff quickly came apart.

I followed her to Barcelona when her visa expired and we lived in a tiny flat, totally content and in love before we realized that nothing was holding us in Spain. We packed a few clothes, some toiletries and a couple of laptops and hit the road. We lived in Bangkok, Buenos Aires and Toronto with many stops in between.
Travel is an extremely expensive luxury.  With a decent career I still have to work to scrape up the money to visit my very geographically dispersed family and friends.  I think few people without financial assets would be able to simply pick up and live in a succession of expensive, world-class cities.  Again, my homeless person surveys are strictly anecdotal, but beautiful women or dashingly handsome men as companions seem absent from their accounts of living rough. 

As for being poor, it made a huge difference for my freedom in the periods of my life that I had the cash to compensate for mistakes or broken things.  It's much less of a sacrifice to live in a studio apartment if you can rent a suite at a local hotel whenever it gets claustrophobic. 

It is fine to be able to make the decision to have few possessions.  It is completely different to not have a choice in the matter. 

Wednesday, March 27, 2013

Recommended Reading

See here for a discussion on a recent paper on health inequality.

 The best sentence in the blog post? 

Cynics may spot the benefit of such an approach for those at the top of the income distribution…

Intellectual Property

Mark Thoma points us towards a potentially really important finding:

By linking a number of different datasets that had not previously been used by researchers, Williams was able to measure when genes were sequenced, which genes were held by Celera's intellectual property, and what subsequent investments were made in scientific research and product development on each gene. Williams' conclusion points to a persistent 20-30 percent reduction in subsequent scientific research and product development for those genes held by Celera's intellectual property.
As we have long discussed on this blog, the justification for intellectual property is to encourage and promote innovation.  There has long been a concern that the innovation would have happened with or without the patent (software patents are a good example of this phenomenon) but a general consensus that the profits from patents increase innovation (due to the rewards generated by a successful innovation).  However, if the granting of a patent were shown to decrease innovation then the argument for granting them would be weakened.

If granting a patent reduces future innovation and the patented innovations would have occurred with or without the patent then the patent process becomes pure rent seeking.  It's clear that these two conditions do not universally hold (i.e. medication discovery as currently constructed is too expensive without a clear path to future profits).  But the possibility that this could be true for same areas of technology is a sobering thought indeed. 

Tuesday, March 26, 2013

New advice column

Emily Oster has an advice column.  Read here.

It contains an excellent explanation of opportunity cost with respect to child rearing.   

Sunday, March 24, 2013


Chris Dillow is strident:
Instead, I suspect what we see with her and with Ukip - and, one could argue, with some who support press regulation whilst favouring social liberalism in other contexts - is asymmetric libertarianism. People want freedom for themselves whilst seeking to deny it to others; this is why some Ukippers can claim to be libertarian whilst opposing immigration and gay marriage. This debased and egocentric form of libertarianism is more popular than the real thing.
But I think he might be on to something.  I have long wondered why Libertarians focus on certain positions (e.g. taxation) and not others (e.g. prisons).  I am not saying all Libertarians focus on taxes and no Libertarian is worried about the criminal justice system.  That would be a straw man version of the argument.

It is more that the attention to these issues seems to be rather selective.  Not all of them: I can find individuals with consistent positions on the hot button issues like drugs, criminal offense, personal freedoms and so forth.  But the focus on, for example, lowering taxes seems much stronger than the focus on reducing the prison population.  Or at least that is one outsiders view.

Weekend movie blogging -- meta spoilers

I was starting to write a post about an old but nicely done 70s movie of the week (Ed Asner, Cloris Leachman and Lloyd Bridges all doing good work but -- God help me -- it's Robert Reed who knocks it out of the park in his big scene). I was specifically interested in the odd way the writer handled the big reveal, having characters start to speculate about it in the middle of the film.

I started to contrast it with a Henry Fonda film that ends with a with a masterfully executed blindside twist but I realized that simply by saying ____ has a great surprise ending I could spoil the film. You might not guess the ending but knowing something was coming could keep you from buying into the story. When the rug was pulled out you'd already have one foot off of it.

Likewise, an Ira Levin novel I was also going to use as an example derives much of it effectiveness from the skillful way the writer slips something very big past you without putting you on your guard, If I tell you Levin pulls a fantastic narrative trick in ____, there's a much better chance that he won't pull it off.

The idea that simply telling someone that there's a spoiler can be a spoiler reminded me of a class of puzzles where before you can solve the puzzle you have to know if you have enough information to solve the puzzle. These are discussed at length by Raymond Smullyan in What Is the Name of This Book. I'll try to dig up my copy and update the post with some examples.

Friday, March 22, 2013

75 years of progress

While pulling together some material for a MOOC thread, I came across these two passages that illustrated how old much of today's cutting edge educational thinking really is.

First from a 1938 book on education*:
" Experts in given fields broadcast lessons for pupils within the many schoolrooms of the public school system, asking questions, suggesting readings, making assignments, and conducting test. This mechanize is education and leaves the local teacher only the tasks of preparing for the broadcast and keeping order in the classroom."
And this recent entry from Thomas Friedman.
For relatively little money, the U.S. could rent space in an Egyptian village, install two dozen computers and high-speed satellite Internet access, hire a local teacher as a facilitator, and invite in any Egyptian who wanted to take online courses with the best professors in the world, subtitled in Arabic.
I know I've made this point before, but there are a lot of relevant precedents to the MOOCs, and we would have a more productive discussion (and be better protected against false starts and hucksters) if people like Friedman would take some time to study up on the history of the subject before writing their next column.

* If you have any interest in the MOOC debate, you really ought to read this Wikipedia article on Distance Learning.

Wow, just wow!

Via Thomas Lumley:
You may have heard about the famous Hawthorne experiment, where raising light levels in a factory improved output, as did lowering them, as did anything else experimental. The original data have been found and this turns out not to be the case.
The mind boggles at just how often I have used this example and how wrong it was.  I have read the paper once, not that closely, but the overall impression I have is that Levitt is correct here. 

Thursday, March 21, 2013

Cloud computing

Kevin Drum
What's different is that Google's products are all cloud-based. When Google Reader goes away on July 1, that's it. It's gone. If it were an ordinary bit of software that I'd installed on my PC, this wouldn't be a problem. It would keep on working for years even if it never got another update. I'd need to replace it eventually—because of an OS upgrade or a desire for new features that finally got too strong—but I'd probably have years to work that out.
I think that this element of the new model of software is worth a lot more attention then it is getting.  Just look at the sim city fiasco and ask what would happen if Microsoft made the same mistakes with a new cloud version of Office.  Now Microsoft is an extraordinarily well run company, so the chances of that are quite small.

But the general trend towards renting access is going to make interuptions of service (or just the internet misbehaving) a much bigger deal. 

Wednesday, March 20, 2013

Apple, J.C. Penney* and fitness landscapes in everything

James Kwak has an excellent piece on Ron Johnson's unfortunate run as CEO of J.C. Penney.
According to today’s Wall Street Journal article, Johnson quickly eliminated coupons and most sales at J.C. Penney.

“Johnson bristled when a colleague suggested that he test his new no-discounts strategy at a few stores. . . . ‘We didn’t test at Apple,’ the executive recalled Mr. Johnson . . . saying.”

Well, yeah. Apple doesn’t discount because they sell stuff that people really, really want and that they can’t get anyplace else. And they don’t test because Steve Jobs refused to. At Penney? Sales have fallen by about 30 percent.

This doesn’t mean Johnson is stupid, or that he’s going to fail as CEO. Apparently he has partially reversed his early decision, which is a good sign. But it brings up a common feature of external CEO hires. Companies in a perceived crisis often look outside for a new leader, hoping for a superman (or -woman) who can singlehandedly turn around the organization. Not completely illogically, they tend to look for people at successful companies. “Make us more like X,” they pray. In Penney’s case, X = Apple.

There are two important questions they tend not to ask, however. First, was Apple successful because of Johnson, or was he just along for the ride? Yes, he was the main man behind the Apple Store (although, according to Walter Isaacson’s book, Steve Jobs was really the genius behind everything). But was the success of the Apple Store just a consequence of the success of the iPhone?

Second, even if Johnson was a major contributor to Apple’s success, how much of his abilities are transferable to and relevant to J.C. Penney? There’s a big difference between selling the most lusted-after products on the planet and selling commodities in second-rate malls. When someone has been successful in one context, how much information does that really give you about how he will perform in a new environment?
The obvious interpretation here is as a cautionary tale of executive hubris, but you can also look at it in terms of fitness landscapes (the following will be fairly straightforward, but if the concept doesn't ring a bell you might want to check herehere, and of course, here).

Let's try thinking in terms of the retail fitness landscape (presented with the usual caveat that I'm way out of my field). Just how distant is the Apple Store from J.C.P.?

Apple Stores are a relatively small boutique chain (400 stores total, 250 in the U.S.) concentrated heavily in prime commercial urban and upscale suburban areas. Their customer demographics tend toward upper income, fashion-conscious early adopters with a demonstrated willingness to pay a premium for quality. Inventories consist of a few heavily-branded, high-quality, high mark-up items, all of which come from one very visible supplier with an excellent reputation. This allows an unusual (perhaps unique -- there's not another Apple) symbiotic relationship. The stores give the supplier a presence and a profit center while the stores benefit from the supplier's powerful brand, large advertising budget and unparalleled PR operation.

In terms of customers, products, brand, retail space, vendors relations, logistics, scale and business model, moving from the Apple Store to JCP was a shift to a distant part of the retail landscape. What Johnson did, in essence, was say "these coordinates are associated with an extremely high point on the landscape (the Apple Store). Even though we've made large shifts in many of these dimensions, we can keep the same coordinates for the other dimensions and we'll find another optima."

To put this in context, here's a useful example from T. Grandon Gill
Suppose, for example, you had a fitness function that mapped the list of ingredients to an objectively determined measure of “taste fitness” for all the recipes in a cookbook. If you were to do a regression on taste (dependent variable) using the ingredients (independent variables), you might find—for instance—that garlic shows a high positive significance. What would that tell you (other than, possibly, that the individuals rating the recipes enjoyed garlic)? What it would definitely not tell you is that you could improve your recipe for angel cake by adding garlic to it. Indeed, the whole notion of applying a technique that assumes linear decomposability to a fitness landscape that is so obviously not decomposable is preposterous.
Substitute a low level of coupons for a high level of garlic and you have a pretty good picture of the JCP strategy.

How do we know the retail landscape is rugged? We don't, but we do have considerable evidence that certain approaches work better in some circumstances than they do in others (i.e. there are multiple local optima). More to the point, Johnson's entire strategy pretty much assumed that the many small and large players in the department store area (including Macy's, Sear, Dillards, Kohls, the pre-Johnson JCP and countless smaller chains and individual stores) were trapped in one or more low-quality optima. When you have this many diverse companies in a market this competitive and this mature, you expect to see a fair amount of something analogous to gradient searching ("That worked; let's do more to it."). If they haven't settled on your optimum point, it's almost certainly because they settled on another.

The lessons -- when you move into an established market you should probably assume the established players know the field and you should probably not assume that what worked somewhere else will work here -- could be (and were) reached without referring to fitness landscapes, but they do make a good framework for approaching a wide variety of problems.

Johnson moved to an unfamiliar region of a probably rugged landscape and refused to explore the surrounding area for higher points despite the fact that numerous other players that had explored the region had settled on a completely different points. When you phrase it this way, it doesn't sound good (of course, Johnson's approach doesn't sound good when you phrase it most ways).

* The 'C' stands for 'Cash' -- no, really.

Tuesday, March 19, 2013

If you actually want to close the achievement gap...

An excellent story from KPCC's Take Two. Considerably more effective in the audio version if you have the time.
Teenager Michelle Zamora has big dreams to become a civil engineer.

“Since 4th grade,” Zamora says, “I told myself I want to go to Stanford University.”

Zamora would be the first in her family to go to college, and as a self-described “smart kid,” Stanford never seemed too far-fetched an idea.

But at age 15, Michelle Zamora made a mistake: she got pregnant. And her dreams of college seemed to vanish.

Like thousands of other California teens, Zamora dropped out of high school.

She is among the majority of the state's teen moms --83%-- that come from low-income households. According to the California Department of Education, the state ranks number one nationwide with its rate of pregnancy among teens.

The worst part, she said, was the way most people assumed she was condemned to future that she didn’t want. People told her “well, you’re just going to be another teenager on welfare,” or “you’re not going to make it.” Zamora started to believe them.

And then she found out about a program in Baldwin Park that has given her renewed hope.

In the late 1990s, officials in the Baldwin Park Unified School District worried that they were losing too many students due to pregnancy. Using federal Early Head Start funds, the district launched an innovative program to ensure teen moms could stay in school.

When Zamora’s daughter was born in 2011, a friend told her about North Park high school which provides on-site daycare so teen moms and dads can complete coursework.

A Continuation high school, North Park enrolls students who failed or dropped out, but now want to finish high school. Its child care program is one of 18 at high schools across Los Angeles county that cater to teen parents. Since 1999, about 60% of North Park students have graduated and gone on to higher education.

Monday, March 18, 2013

Today's vocabulary term is "flack-to-hack ratio"

Felix Salmon has one of those that-explains-a-lot posts up on his blog:
Quartz, in this deal, is getting one article, which needs a fair amount of editing; it’s a tiny proportion of Quartz’s daily output. Meanwhile, Brandtone is getting something very valuable indeed. Just look at the US flack-to-hack ratio: it’s approaching 9:1, according to the Economist, which means that for every professional journalist, there are nine people, some of them extremely well paid, trying to persuade that journalist to publish something about a certain company. That wouldn’t be the case if those articles weren’t worth serious money to the companies in question.

How valuable? How about somewhere between $250,000 and $1 million? That’s the amount of money that Fortune’s ad-sales team was asking, earlier this month, for a new product called Fortune Trusted Original Content:

Similar to licensed editorial content, TOC involves creating original, Fortune-branded editorial content (articles, video, newsletters) exclusively for marketers to distribute on their own platforms.

After news of the TOC program appeared, it was walked back — abolished, essentially. You can see why Fortune’s top editorial brass would be uncomfortable with the idea that Fortune editorial content could be commissioned by, and appear for the sole benefit of, advertisers. So now they’re going back to the old model, of just allowing advertisers to license (reprint, basically) stories which were independently commissioned and published by Fortune’s editors.

Still, the price point on the now-aborted TOC program is revealing. The cost of the content, from a “trusted freelancer”, would probably not be much more than a couple of thousand dollars — but the cost of the content to the advertiser could be as much as $1 million. The difference is entirely accounted for by the value of the Fortune brand.
The flack-to-hack ratio may have something to do with another recurring topic, the almost complete lack of coverage of the reemergence of over-the-air television (see here, here, here, here, and... hell, just do a search). Weigel Broadcasting may be an extraordinarily well run company, but as long as they run a largely flackless operation, you'll probably never hear about them.

I apologize if I posted this before...

... but this Marketplace piece on a program to get disadvantaged families out of bad neighborhoods is definitely worth checking out.

Sunday, March 17, 2013

Weekend movie blogging -- Herman Mankiewicz in Oz

With Oz, the Great and Powerful being both at the box office, it's worth taking a minute to give a little credit to someone who made an essential but largely unrecognized contribution to the original classic, Herman Mankiewicz. Famed film historian/director/sycophant, Peter Bogdanovich has spent the past few decades trying to undermine Mankiewiez's reputation since Pauline Kael had the temerity to suggest that Mankiewicz was the primary author of the script of Citizen Kane.

Bogdanovich has sold the "Herman Mankiewicz was a talented hack" line to countless credulous journalists and film students over the years and supported the claim with a highly selective recounting of Mankiewiez's resume.  With Oz back in such a big way, one of the films Bogdanovich omits is particularly relevant:
In February, 1938, he was assigned as the first of ten screenwriters to work on The Wizard of Oz. Three days after he started writing he handed in a seventeen-page treatment of what was later known as "the Kansas sequence". While Baum devoted less than a thousand words in his book to Kansas, Mankiewicz almost balanced the attention on Kansas to the section about Oz. He felt it was necessary to have the audience relate to Dorothy in a real world before transporting her to a magic one. By the end of the week he had finished writing fifty-six pages of the script and included instructions to film the scenes in Kansas in black and white. His goal, according to film historian Aljean Harmetz, was to "to capture in pictures what Baum had captured in words--the grey lifelessness of Kansas contrasted with the visual richness of Oz." He was not credited for his work on the film, however.
There are, of course, many things that have to go right to produce a truly iconic film, but if you had to pick the one element that made the film work and made people remember it, you'd probably have to go with Mankiewicz's contribution.

Saturday, March 16, 2013

Playing with paper over at You Do the Math

Been thinking a lot about paper from a material-science standpoint (the mind wanders when SAS runs slowly), specifically about using paper to teach kids about the physical properties of different shapes and how we test them.

I've kicked off an ongoing thread on the subject at my math teaching blog. The first (with the admittedly pretentious title, "Reseeing Paper") is an overview of paper as a way of exploring shape. The second ("Paper Towers") lays out the rules for some engineering projects/competitions suitable (almost without alteration) for classes ranging from fourth grade to freshman engineering (though one would like to think that the results for the freshmen would be a bit more sophisticated). The projects would also be suitable for science-based family activities. There is more of this to come (I haven't even started on corrugation).

Check it out and if you know of any teachers who are looking for new (and cheap) manipulatives, please send them the links. There are any number of potential lesson plans here.


p.s. Suggestions are always welcome.

Friday, March 15, 2013

When you hear proposals to control tuition by reducing instruction cost...

When you hear proposals to control tuition by reducing instruction cost (in the recent discussions of MOOCs for example), here are a couple of numbers you should keep in mind. They haven't been adjusted for inflation and they're based on a sample size of one, but I still thing they'll gave you a pretty clear picture.

Back in the Nineties I did a four year stint as a lecturer at a large state university. The standard load for lecturers was four courses a semester and the pay was seventeen thousand and change. (I was only on a half load with the other half of my funding coming from other duties like supervising grad students but the following numbers still hold).

If you break it down that comes to less than twenty-five hundred a three hour course. With the exception of a couple of upper level courses, my sections generally ranged from twenty-five to one hundred and fifty students. That means that the per student cost associated with the lecture portion of one of those courses ranged from less than one hundred dollars at the top end to around fifteen dollars at the bottom.

If someone has some current numbers I'd be glad to update the post but as far as I can tell, while tuition has continued to climb since my lecturer days, adjunct salaries have, at best, kept up with inflation and certainly haven't grown enough to be a major driver of education costs. But what's really amazing isn't that you can get people to take these jobs at this pay; it's that you can find wildly overqualified people -- promising scholars, gifted lecturers -- willing to take these jobs. That's how flooded the supply of would-be professors is.

There are well-paid, even over-compensated professors out there but they are all paid primarily for something other than teaching, be it their research or their reputation (which reflects on the school) or the grants they pull in. We can and probably should have a serious discussion about these roles (maybe starting here) but that's a different conversation.

As for controlling tuition by reducing instructor costs, that conversation has to start with a realistic picture of how much people who are hired simply to teach actually make.

Thursday, March 14, 2013

The Rise of P-Value

In the middle of a recent conversation prompted by this post by Andrew Gelman, I struck me that I couldn't recall encountering the term p-value before I started studying statistics in the Nineties. These days you frequently run across the term in places like the NYT article Gelman cited or this piece in the Motley Fool; were they always there and I just missed them?

Fortunately we have Google's Ngram viewer to resolve these questions and apparently the answer is a qualified yes. While people were talking about p-values at the beginning of the decade, more people were talking about them by the end.

The question now is how much of that growth is attributable to general interest writing like the NYT.

Wednesday, March 13, 2013

Epidemiology and Truth

This post by Thomas Lumley of Stats Chat is well worth reading and thinking carefully about.  In particular, when talking about a study of process meats and mortality he opines:

So, the claims in the results section are about observed differences in a particular data set, and presumably are true. The claim in the conclusion is that this ‘supports’ ‘an association’. If you interpret the conclusion as claiming there is definitive evidence of an effect of processed meat, you’re looking at the sort of claim that is claimed to be 90% wrong. Epidemiologists don’t interpret their literature this way, and since they are the audience they write for, their interpretation of what they mean should at least be considered seriously.

I think that support of an association has to be the most misunderstood piece of Epidemiology (and we epidemiologists are not innocent of this mistake ourselves).  The real issue is that cause is a very tricky animal.  It can be the case that complex disease states have a multitude of "causes".

Consider a very simple (and utterly  artificial) example.  Let assume (no real science went into this example) that hypertension (high systolic blood pressure) occurs when multiple exposures over-whelms a person's ability to compensate for the insult.  So if you have only one exposure off of the list then you are totally fine.  If you have 2 or more then you see elevated blood pressure.  Let's make the list simple: excessive salt intake, sedentary behavior, a high stress work environment, cigarette smoking, and obesity.  Now some of these factors may be correlated, which is its own special problem.

But imagine how hard this would be to disentangle, using either epidemiological methods or personal experimentation.  Imagine two people who work in a high stress job, one of which eats a lot of salt.  They both start a fitness program due to borderline hypertension.  One person sees the disease state vanish whereas the other sees little to no change.  How do you know what was the important factor?

It's easy to look at differences in the exercise program; if you torture the data enough it will confess.  At a population level, you would expect completely different results depending on how many of these factors the underlying population had.  You'd expect, in the long run, to come to some sort of conclusion but it is unlikely that you'd ever stumble across this underlying model using associational techniques. 

The argument continues:
So, how good is the evidence that 90% of epidemiology results interpreted this way are false? It depends. The argument is that most hypotheses about effects are wrong, and that the standard for associations used in epidemiology is not a terribly strong filter, so that most hypotheses that survive the filter are still wrong. That’s reasonably as far as it goes. It does depend on taking studies in isolation. In this example there are both previous epidemiological studies and biochemical evidence to suggest that fat, salt, smoke, and nitrates from meat curing might all be harmful. In other papers the background evidence can vary from strongly in favor to strongly against, and this needs to be taken into account.
This points out (correctly) the troubles in just determining an association between A and B.  It's ignoring all of the terrible possibilities -- like A is a marker for something else and not the cause at all.  Even a randomized trial will only tell you that A reduces B as an average causal effect in the source population under study.  It will not tell you why A reduced B.   We can make educated guesses, but we can also be quite wrong.

Finally, there is the whole question of estimation.  If we mean falsehood to be that the size of the average causal effect of intervention A on outcome B is completely unbiased then I submit that 90% is a very conservative estimate (given if you make truth an interval around the point estimate to the precision of the reported estimate given the oddly high number of decimal places people like to quote for fuzzy estimates). 

But that last point kind of falls into the "true but trivial" category . . .

Tuesday, March 12, 2013

Landscapes in everything


One of the issues I have with economics exceptionalism is the word 'everything,' as in "markets in everything" or "the hidden side of everything." Not that there's anything wrong with applying economic concepts to a wide variety of questions (I do it myself), but at some point they become overused and start crowding out ideas that are better in a given context.

Think about all the times you heard phrases like the 'marriage market' often followed by the implicit or explicit suggestion that the tools of economics hold the key to understanding all sorts of human behavior even in cases where the underlying assumptions of those tools probably don't apply. Now, for example, compare that to the number of times you've recently heard someone describe something as a fitness landscape when they weren't talking about evolution or physics (OK, that's not the term physicists generally use but the concept is basically the same).

Landscapes are a powerful and widely applicable concept, arguably more so than markets (they are also a long-time fascination of mine). Ideas like gradient searches, perturbation, annealing and, most of all, local optimization are tremendously useful, both to explain complex problems and to suggest approaches for solving them. Once you start thinking in those terms you can see landscapes about as often as Tyler Cowen sees markets.

You can even find researchers coming up with the kind of unexpected, everyday examples that you might expect in a Steven Levitt column.

My favorite recent example (at least recent to me) is T. Grandon Gill's observation that recipes in a cookbook are essentially the coordinates of local optima on a culinary fitness landscape where the amount of each ingredient are the dimensions and taste is the fitness function (technically we should add some dimensions for preparation and make some allowance for the subjectivity of taste, but I'm keeping things simple).

This is a great example of a rugged landscape that everyone can relate to. You can find any number of delicious recipes made with the same half dozen or so ingredients. As you start deviating from one recipe (moving away from a local optima), the results tend to get worse initially, even if you're moving toward a better recipe.

Approaching something as a rugged landscape can provide powerful insights and very useful tools, which leads to another concern about economic exceptionalism -- economics as a field tends to make little use of these models and many economists routinely make modeling assumptions that simply make no sense if the surface being modeled really is rugged.

I asked Noah Smith* about this and as part of his reply he explained:
But for analyzing the equilibrium state of the economy - prices and quantities - economists tend to try as hard as they can to exclude multiple equilibria. Often this involves inventing arbitrary equilibrium criteria with zero theoretical justification. This is done routinely in micro (game theory) as well as in macro. An alternative procedure, commonly used in macro by DSGE practitioners, is to linearize all their equations, thus assuring "uniqueness". Some researchers are averse to this practice, and they go ahead and publish models that have multiple equilibria; however, there is a strong publication bias against models that have multiple equilibria, so many economists are afraid to do this. An exception is that some models with two equilibria (a "good" equilibrium and a "bad" or "trap" equilibrium) do get published and respected. Models with a bunch of equlibria, or where the economy is unstable and tends to shift between equilibria on its own at a high frequency, are pretty frowned upon.
This doesn't mean that economists can't work with these concepts, but it does mean that as economists increasingly dominate the social sciences, approaches that don't fit with the culture and preferred techniques of economics are likely to be underused.

And some of those techniques are damned useful.

* now with source.

Monday, March 11, 2013

Some epidemiology for a change

John Cook has an interesting point:
When you reject a data point as an outlier, you’re saying that the point is unlikely to occur again, despite the fact that you’ve already seen it. This puts you in the curious position of believing that some values you have not seen are more likely than one of the values you have in fact seen.
This is especially problematic in the case of rare but important outcomes and it can be very hard to decide what to do in these cases.  Imagine a randomized controlled trial for the effectiveness of a new medication for a rare disease (maybe something memory improvement in older adults).  One of the treated participants experiences sudden cardiac death whereas nobody in the placebo group does. 

One one hand, if the sudden cardiac death had occured in the placebo group, we would be extremely reluctant to advance this as evidence that the medication in question prevents death.  On the other hand, rare but serious drug adverse events both exist and can do a great deal of damage.  The true but trivial answer is "get more data points".  Obviously, if this is a feasible option it should be pursued. 

But these questions get really tricky when there is simply a dearth of data.  Under these circumstances, I do not think that any statistical approach (frequentist, Bayesian or other) is going to give consistently useful answers, as we don't know if the outlier is a mistake (a recording error, for example) or if it is the most important feature of the data.

It's not a fun problem. 

More weekend work avoidance -- the pleasures of microbudgets

Watched the first and second arcs of a fairly obscure British science fiction show from 1979 called Sapphire and Steel. It was apparently intended as a low-budget answer to Doctor Who (which those familiar can attest was not exactly the Avatar of the Seventies).  The result was a sci-fi/fantasy/horror show that had to be shot on standing sets with small casts and very limited special effects.

The result is some really impressive constrained problem solving by writer P.J. Hammond (with considerable assistance from directors David Foster, Shaun O'Riordan and the show's solid leads, David McCallum and Joanna Lumley, the only expensive aspects of the production). Hammond did sometimes lapse into dramatic Calvinball, obviously making up new rules now and then to get himself out of narrative corners, but those bits are easy to overlook, particularly when watching the ways he found to work around the rules he was handed by the producers.

In lieu of optical effects and creature make-up, you get a spot of light on the floor, a shadow on the wall, an ordinary thing in a place it shouldn't be. In an ironic way, the show would almost certainly look cheaper now if they had spent the extra money on those late Seventies effects then. In a sense, they didn't have enough money to be cheesy (except perhaps in the opening title).

There's a bigger point to be made about the costly vs. the clever but the weekend is almost up and my work is going to be unavoidable in a few hours.

Sunday, March 10, 2013

Weekend gaming -- new entries at You Do the Math

I've got three big ongoing threads planned for my teacher support blog, one on the SAT and one on a special class of manipulatives, and one on teaching programming, so naturally I've been avoiding those topics and writing about games instead: If you also have an interest in games and work to avoid, you might drop by and check out:

The Exact Chaos Game -- fleshing out a suggestion by John D. Cook, this lets players bet on iterations of a surprisingly unpredictable function.

Kriegspiel and Dark Chess -- more Wikipedia than me but worth checking out if you'd like to see what chess might look like as a game of imperfect information.

Facade Chess -- along the same lines, here's an "original" imperfect-information variant where a subset of the  pieces may be disguised as other pieces.

Saturday, March 9, 2013

Do op-ed writers provide their own hyperlinks?

Or is some intern handed the copy and told to find some appropriate citations? I generally assume that the links are an intrinsic part of anything written specifically for online consumption but what about the online version of something primarily intended for print?

Take this op-ed by Joe Scarborough and Jeffrey D. Sachs writing for the Washington Post which starts with the following paragraph:
Dick Cheney and Paul Krugman have declared from opposite sides of the ideological divide that deficits don’t matter, but they simply have it wrong. Reasonable liberals and conservatives can disagree on what role the federal government should play yet still believe that government should resume paying its way.
As a commenter on Krugman's blog pointed out, if you click on Krugman's name in that paragraph, you'll end up at a post that starts as follows:
Right now, deficits don’t matter — a point borne out by all the evidence. But there’s a school of thought — the modern monetary theory people — who say that deficits never matter, as long as you have your own currency.

I wish I could agree with that view — and it’s not a fight I especially want, since the clear and present policy danger is from the deficit peacocks of the right. But for the record, it’s just not right.
In other words, to support the claim that Krugman said deficits don't matter, Scarborough and Sachs point to Krugman saying explicitly that people who say deficits don't matter are wrong. Krugman then spends pretty much the entire post arguing that deficits will matter a great deal once we're out of the liquidity trap. Here's the key section.
So we’re talking about a monetary base that rises 12 percent a month, or about 400 percent a year.

Does this mean 400 percent inflation? No, it means more — because people would find ways to avoid holding green pieces of paper, raising prices still further.

I could go on, but you get the point: once we’re no longer in a liquidity trap, running large deficits without access to bond markets is a recipe for very high inflation, perhaps even hyperinflation. And no amount of talk about actual financial flows, about who buys what from whom, can make that point disappear: if you’re going to finance deficits by creating monetary base, someone has to be persuaded to hold the additional base.
This isn't to say that this post is in agreement with the op-ed; in terms of immediate action they are taking completely opposite positions, It would have easy to spell out the distinction, but instead Scarborough and Sachs simply make a claim then point us to something that directly contradicts it.

The strange thing here is that you could find any number of posts where Krugman focuses on the case for stimulus and largely or entirely ignores the dangers of deficits. Any of these would have supported Scarborough and Sachs' thesis. Instead, though, the authors pick possibly the strongest anti-deficit argument Krugman has made in the past five years.

I can understand Scarborough. He is, and I don't mean this as a pejorative, a TV personality. That's a rare and valuable talent and Scarborough is very good at it. It is not, however, a profession that depends upon reputation in the conventional sense. As long as a TV personality does nothing to betray his public persona, almost all press is good press.

For Sachs, though, reputation is extraordinarily important. This is an important and influential scholar, someone whose ideas carry great weight with policy makers. Here's a representative passage from Wikipedia:
Sachs is the Quetelet Professor of Sustainable Development at Columbia's School of International and Public Affairs and a Professor of Health Policy and Management at Columbia's School of Public Health. He is Special Adviser to United Nations Secretary-General Ban Ki-Moon on the Millennium Development Goals, having held the same position under former UN Secretary-General Kofi Annan. He is co-founder and Chief Strategist of Millennium Promise Alliance, a nonprofit organization dedicated to ending extreme poverty and hunger. From 2002 to 2006, he was Director of the United Nations Millennium Project's work on the Millennium Development Goals, eight internationally sanctioned objectives to reduce extreme poverty, hunger, and disease by the year 2015. Since 2010 he has also served as a Commissioner for the Broadband Commission for Digital Development, which leverages broadband technologies as a key enabler for social and economic development.
Silly, avoidable errors undercut Sachs' ability to continue this good work.

Which leads back to my original question. Did Jeffrey Sachs actually agree upon a link that contradicted the point he was trying to make or are links, like headlines and blurbs, often added after a piece is submitted?

Thursday, March 7, 2013

More on Marissa Mayer

I think that this is a very good point:
It also seems like a feminist mistake to expect women entrepreneurs to create little utopias instead of running extremely successful businesses. Mayer was attacked recently for her decision not to allow employees to work at home. She is a woman, this line of thinking goes, how could she think women should have to work away outside of their houses, away from their children? But why should Marissa Mayer have some special responsibility to nurture her employees with a cozy, consummately flexible work environment just because she is a woman? Isn’t her responsibility to run a company according to her individual vision? If we want powerful female entrepreneurs shouldn’t we allow them to pursue entrepreneurial power?
 I am not actually 100% sure that the decision to end "work at home" really hurt woman at Yahoo! (as a class, clearly individual workers of both genders could have had their work lives disrupted) given that men are more likely to work at home than women.  Mayer's previous company (Google) tries to limit the number of telecommuters and it is hardly unreasonable that a new CEO would want to draw on successful business models that she has personal experience with. 

Now could this policy change have been done more artfully? Sure.  But I am amazed by the duration of this discussion in the media and how much insight it is bringing into the whole work at home phenomenon. 

Admittedly, it is a competitive field

Thomas Lumley is an early contender for identifying the worst chart of 2013.  This special breed of awful is accomplished by creating a chart that actually takes more effort to process than text describing the differences would.  Since the point of charts is to convey information efficiently, there really is no good reason for this chart to exist. 

Of course, as a long time SAS programmer I am biased against graphical displays of data in general (you would be too if you had to use gplot and gchart).  But I think that this example will be disliked by the R and STATA crowd too. 

Wednesday, March 6, 2013

Forwarded almost without comment

This story from Reuters is outside of my area of expertise so I'm just going to make this blanket recommendation. This is a solid piece of reporting on the not easy-to-cover fields of epidemiology, biostatistics and the economics of health care.

Special Report: Behind a cancer-treatment firm's rosy survival claims

Edit (Joseph): Andrew Gelman correctly points out that the authors are Sharon Begley and Robin Respaut.  This report is useful to me as another reason that we need to have a control arm for randomized trials.  It isn't enough to know what the rate is for conventional care and contrast a novel therapy with it.  You need to also account for the selection effects among the population receiving the novel therapy.  Randomization is a very nice way to accomplish this outcome in a generally understood manner. 

Tuesday, March 5, 2013

Educational dilemmas

This is entirely correct:
You can hold us accountable for how much our graduates learn.  You can hold us accountable for how many students graduate. You can even hold us accountable for both of those at the same time.  And, amazingly enough, you can hold us accountable for doing this while educating a broad spectrum of public high school grads. What you cannot do is hold us accountable for all of those things AND the cost/time required for them to graduate.  Getting lots of people through in a short time frame, and teaching them a lot along the way, requires a lot of attention and a lot of support (whether financial aid so they can focus on school rather than work, or tutoring and small classes and all that, or even extracurriculars to help them develop certain “soft skills”), and that costs money.  So pick any two: Quality, quantity, and cost (which is directly related to time).  If you say that students are learning less and less, believe me, you’re right.  Just don’t tell me that you want me to fix that AND graduate more students without some major changes to How Things Are Done.

I think the same principle applies to high school education.  Due to the modern phobia of taxes, people do not want to pay more for education.  Yet there is a constant pressure for students to lean more and for education to inclusive/accessible.  I am all for finding ways to be more efficient and evidence based in educational spending.  But it doesn't help if the initial conditions are impossible to meet.

Monday, March 4, 2013

Things that tempt you to write posts you don't have time for

Ludwig von Mises:
The age in which the radical anticapitalistic movement acquired seemingly irresistible power brought about a new literary genre, the detective story. The same generation of Englishmen whose votes swept the Labour Party into office were enraptured by such authors as Edgar Wallace. One of the outstanding British socialist authors, G. D. H. Cole, is no less remarkable as an author of detective stories.

The Passing Tramp admirably handles the rebuttal, complete with a reference to that sterling Tory, Lord Wimsey.

Sunday, March 3, 2013

Another solution

Paul Krugman has a good point:
Still, isn’t it bizarre that governors who protest bitterly about the cost of Obamacare, and in general about wasting taxpayers’ money, are willing to throw away lots of money via corporate welfare? Actually, no; it’s only puzzling if you think they believe anything they say.
The context is the decision to allow Arkansas to expand the Affordable Care Act exchanges instead of Medicaid.  Aaron Carroll:
Many claimed that the ACA cost too much. They said it would raise the deficit. They opposed the expansion not only because it raised the federal price tag, but also because it was “fiscally unsustainable” for states in the long run. I took them at their word.

I’m now surprised that they prefer a solution that costs more.
Maybe what we really need to do is randomize?  After all, the secondary benefits of high health care spending are definitely unclear.  The United States isn't exceptional relative to Canada or France in terms of medical outcomes.  The benefits to medical innovation could be attempted via a stronger NIH with a broader mandate.  So the only real question is whether private insurance can result in innovations that reduce overall costs and/or improve outcomes.

Surely randomization of states could provide some really useful information and solve this question more directly?  After all, don't we think of it as the gold standard for a causal inference?  And it would be easy to randomize states to several possible versions of the ACA (no expansion, exchanges, Medicaid expansion, public option to allow the uninsured to purchase Medicaid). 

Is there a good reason not to do this?

P.S. Here is a good example of randomization giving us information in an area that is equally difficult for inference.

Saturday, March 2, 2013

Extremes in student feedback

After I'd been teaching at a school in Watts for a while, I learned that my predecessor had once been overpowered and left tied to his chair by an angry class. This struck me as notable because

A. Despite its location, this was not a rough school

B. My predecessor had been tied to a chair.

When I pressed other faculty members for more details, they explained (rather nonchalantly for my taste), "he was a really bad teacher."

Obviously, most jobs are easier and more pleasant if you're good at them, but this is particularly true in education. Teachers face constant, immediate and often intense feedback from students, something that is greatly intensified when you go to disadvantaged schools in the inner-city or poor rural areas like the Mississippi Delta (where I also taught).

Students get angry at bad instruction and they take advantage of bad classroom management. When you add the amplification that comes with the complex social dynamics of kids and adolescents, teaching can be a truly miserable job if you can't get the hang of doing it right.

This is a large part of the reason why so many new teachers leave the profession. Even after having invested years of study and tens of thousands of dollars, they walk away with a degree that's good for little else because, for them, the job actually is that terrible. By contrast, for those who are good at it, who can explain ideas clearly and establish a rapport with kids and keep a class focused and on task, teaching can be a most enjoyable and satisfying job.

You don't have to be a statistician to see the potential selection effect here. It should certainly be addressed when discussing the impact of bad teachers or proposing incentive pay/dismissal plans for improving education.

It should be addressed but it usually isn't.

Friday, March 1, 2013

Like judging an archery contest after they took down the target...

This is a really small part part of a bigger story (and probably the subject of more posts) but having been on both sides of video evaluations I had a personal problem with this statement from Thomas Kane (which comes to us via Andrew Gelman),
While the mean score was higher on the days that the teachers chose to submit, once you corrected for measurement error, a teacher’s score on their chosen videos and on their unchosen videos were correlated at 1.
Just to be clear, I don't have any problem with this kind of evaluation and I really like Kane's point about using 360s for teachers, but the claim of perfect correlation has raised a red flag for almost every statistically literate person who saw it. You can see an excellent discussion of this at Gelman's site, both in the original post and in the comments. All the points made there are valid but based on my experience I have one more stick for the fire.

For the sake of argument, let's assume that the extraordinary idea that rank is preserved, that the nth teacher on his or her best day is still worse than the (n+1)th teacher on his or her worst day, is true. For anything more than a trivially small n that would suggest an amazing lack of variability in the quality of lessons from teachers across the spectrum (particularly strange since we would expect weaker and less experienced teachers to be more variable).

But there's a source of noise no one's mentioned and in this case it's actually a good thing.

Except for special cases, teachers walk through the door with a great deal of information about their classes; they've graded tests and homework papers; they've seen the reaction to previous lessons, they've talked with students one-on-one. You would expect (and hope) that these teachers would use that information to adjust their approach on a day to day basis.

The trouble is that if you're evaluating teachers based on an observation (particularly a video observation), you don't have any of that information. You can't say how appropriate a given pace or level of explanation is for that class that day. You can only rely on general guidelines.

Which is not to say that good evaluators can't form a valuable assessment based on a video of a lesson. I'm a big believer in these tools both for staff development and (within reason) evaluation, but it's a inexact and often subjective process. You can get a good picture and diagnose big problems but you will never get the resolution that Kane claimed.

There are other problems with this interview, but the correlation of one should have been an easy catch for the reporter. You should never let an interview subject go unchallenged when claiming perfect results.