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.

Wednesday, February 27, 2013

More on Yahoo! and flex time

A lot of the framing of the Yahoo! decision to ban work at home has been painting it as anti-family or anti-feminism.  Dana Goldstein has a very good refutation of this idea.  A couple of good points:

No one is forcing me to take sole responsibility for these tasks. If I don't do them when I'm "working from home," they will still get done. My boyfriend and I will split them up, or do them together. But here's the thing: It's really hard for me to be at home and ignore my domestic to-do list. I have a voice in my head telling me that until my apartment is neat, clean, and stocked with fresh food, it's perfectly okay to procrastinate on my real jobs, the ones for which I get paid: reporting, writing, and editing. After nearly three years of freelancing, I've learned that I shouldn't work from home more than one or two days per week. I now commute from Brooklyn into "the city" almost every morning, to work at the New York Pubic Library on 5th Avenue and 42nd Street. Yes: I voluntarily spend my days in midtown Manhattan, eat lunch at the ubiquitous Hale & Hearty Soups, and dodge tourists in the subway.


So here's my tentative conclusion. Flex-time is a feminist issue. Working from home full time? Maybe not so much. And here are some very definite feminist issues: Access to high-quality, affordable childcare. Paid sick leave, maternity leave, and paternity leave. Male partners who pull their weight at home.


I also think that there is an issue of priviledge involved in these discussions.  Nobody has any trouble with the idea that an employee of McDonald's is unlikely to be able to effectively work from home.  In fact, there is evidence that employers in these sectors are trying to schedule time very flexibly in order to improve efficiency (at the cost of being able to offer a predictable schedule to employees). 

It is true that the best way to manage knoweldge based workers is via performance based metrics.  But these can be very difficult to implement if the office also has a very flexible reporting structure.  It is true that counting cars in the parking lot is a bad plan at the individual level.  But that is an issue of flex time and not the ability to work from home.  In the face of managers with growth opportunities, managing remote workers is harder than local workers (I have done both and the former requires a lot more finesse). 

So I think that Dana is on to something pretty important here. 

Monday, February 25, 2013

Yahoo! is getting bad press

But maybe it shouldn't be.  There has been a lot of discussion about the end of the work from home program at Yahoo! but I was pretty convinced that there was a business case for it by these two points:

"A lot of people hid. There were all these employees [working remotely] and nobody knew they were still at Yahoo."

Mayer is happy to give Yahoo employees standard Silicon Valley benefits like free food and free smartphones. But our source says the kinds of work-from-home arrangements popular at Yahoo were not common to other Valley companies like Google or Facebook. "This is a collaborative businesses."


The first sounds like a very tough HR problem to solve without bringing everyone in so that they can be integrated into the business.  The second is an excellent business case for doing so as a way of enhancing productivity.  The piece that is always hard about working from home arrangements is that people are very defensive about them.  And they should be -- it is a very nice benefit.  But it also makes it a lot harder to collaborate with others and to manage reports. 

The framing of it as a blow to working parents seems to be a bit odd to me.  I would be much more concerned about parents who are working in low wage employment situations without the resources to access things like daycare. 

Health care costs: a never-ending saga

There is a fascinating piece on health care costs in America that has been getting a lot of attention. There have been a lot of responses but I want to discuss one of the unhelpful ones.   In it, the argument is:

Writ large, this is how health care billing works.  Insurers won't let them charge for one thing--nursing care, say--so instead they bill you for the Tylenol at $20 per.  Or they bill someone else, someone who pays more.  Or they double what they charge uninsured patients in the expectation that the bill will, for most people, eventually be written down by some large percentage.


The web of cross-subsidies, underpayments, overpayments, and upcoding is opaque to everyone except the adminstrators.  And they are not, as Brill observes, eager to make any of it clearer.  In part because they genuinely feel, as does the middle manager in our story, that they are forced into these little subterfuges to recover legitimate costs that short-sighted bean-counters are refusing to cover.
I think this is a completely unhelpful perspective.  It basically argues that the issue in health care costs is over regulation, ironically by other private sector actors.  However, it ignores the general issues of lack of bargaining power in an emergency room and opaque information.  Generally, we do not see a ton of hidden costs and a high pressure sales environment to be idea in other industries.

This is even more clear when the alternative is rate setting, by some sort of regulatory agency.  This is the normal approach in high income countries and it seems to lack a massive downside.  Sure, it reduces spending on medicine which can reduce the incentive for innovation in some cases.  But it can also increase the incentives in others -- when you can't just shift the costs for poor process control to customers then you might improve the process. 

So price transparency would seem to be the minimum level of reform . . . 

Sunday, February 24, 2013

Value added testing

This article is worth reading throughout.  However, the most relevant passage is:

Because student performance on the state ELA and math tests is used to calculate scores on the Teacher Data Reports, the tests are high-stakes for teachers; and because New York City uses a similar statistical strategy to rank schools, they are high-stakes for schools as well. But the tests are not high-stakes for the eighth-graders at Anderson. By the time they take the eighth-grade tests in the spring of the year, they already know which high school they will be attending, and their scores on the test have no consequences.
Seriously, can no student of incentives not see how this could go terribly, terribly wrong?  The students could, for example, decide to blow the test because the teacher was overly rigorous. 

This is why I am less skeptical about metrics like the SAT.  It is still flawed as all observational research is tricky to derived unbalanced estimates from.  But in this case, the students, the teacher and the school all have something at stake in their performance on the exam. 

They're just not paying Gelman's preferred currency -- the odd economics of access

This post from Andrew Gelman on a truly bad graph and this story from NPR had a common element that caught my eye, partly because I've been thinking about the role connections play in careers and economic mobility.

Here's the relevant passage from Gelman:
All ugliness aside, this reminds me of a story that I haven’t had a chance to share . . . until now. The bit on the above infographic about “C-level execs” reminds me of something that happened a couple years ago, when I was invited to speak at an event, “called “The 2012 Election: Predicted Outcomes and Implications for Your Business,” for “an association of C-suite executives.” I responded that I was interested and told them my fee, to which they responded:

"I am glad to hear that you are interested in this opportunity. However, we don’t compensate speakers as we find that most are interested in the opportunity to be in front of a room full of high quality C-suite executives."

Is that for real? I speak to all sorts of people for free (for example, I just spoke last month at a datatviz meetup), but I was surprised to hear that an association of business executives weren’t planning to pay. So I declined. I say this not to imply that I’m some sort of anti-corporate crusader (after all, I would’ve been happy to talk for pay!) but to express my bafflement at the whole “C-level executive” thing. What’s going on with that?
And here's the opening of the NPR story:
CNBC is far and away the television ratings leader in the financial cable news business. Now, evidence arrives that its executives, producers and reporters are going to great lengths to maintain its status.

The channel has adopted a policy that prohibits guests from appearing on rival channels amid breaking news if they want to be seen by CNBC's larger audience.
In both cases, it seems that the party providing the service is, in a sense, paying the party receiving it. The Chief ____ Officers would receive actionable business intelligence; CNBC would receive valuable on-air talent. You would expect the recipients to try to compensate for these services either directly on indirectly. Instead the company in the first anecdote insists on getting for free what would normally be a well compensated service while CNBC actually puts additional demands and restrictions on the people providing the free service.

Of course, that's not what's going on, at least not most of the time. While Gelman really was a researcher who was offering to present findings of potential value to a company, most similar presentations are actually sales pitches. I'm going to be a bit vague here because I'm currently working in the corporate world, but without naming names, tremendous amounts of capital is drained from American businesses every year by researchers with a slick HBR paper, an inspirational story and a new set of buzz-words.

If you can get a C-level executive interested in your product you can charge obscene amounts of money for years. Better yet, the metrics for success are ill-defined to nonexistent. The only real barrier to becoming the next Tom Peters is access to someone at or near the top of a company. It's easy to understand why companies think they can get research presented for free.*

Something similar is going on in the CNBC example. The majority of the people interviewed on CNBC are either selling something -- a book, some stocks, themselves -- or are building and maintaining a brand. Doing these things requires getting access to large numbers of people. You could manage this by buying advertising (most effectively on a targeted platform like CNBC) but ads are expensive and, even before TiVo they were often avoided either through channel surfing or, before the remote, simply leaving the room for a snack or a bathroom break.

Getting your access as part of regular programming and having it labeled as news is a far better way of doing things. You can why the interviewees would put up with restrictions.

This does, of course, raise questions about conflict of interest and journalistic integrity, but that's a topic for another post.



* This still leaves unexplained why executives would want to, as Gelman points out in this comment, waste their time with inferior speakers to avoid paying a relatively trivial amount of money. Thoughts on that will have to wait for an upcoming post.

UPDATE: This comment from Felix Salmon throws some amusing light on an event similar to the one in Gelman's anecdote.