Monday, November 28, 2011
I hate John D. Cook
As God as my witness, I swear I was getting ready to do a post looking at argument from authority in terms of informative priors.
Apple Stock
Karl Smith is bearish on Apple:
This is really one of the paradoxes of the stock market. It is not clear whether or not companies that do not issue dividends will ever be investments that pay off. The longer Apple puts its cash in executive compensation without rewarding owners, the higher the risk that Karl Smith is right.
How many rich families do you know that sustained multi-generational wealth via the stock market? How many do it with real assets? It is worth thinking about.
On the one hand you can buy Apple stock for $375 a share and pay $7 to ScottTrade. On the other hand I also have a trash can in which you can deposit your $375, pay me $5 and I will set it on fire for you.
Clearly, I am offering the better deal as in both cases you have approximately zero probability of getting your money back and I am willing to burn it for $5 whereas you have to pay ScottTrade $7.
This is really one of the paradoxes of the stock market. It is not clear whether or not companies that do not issue dividends will ever be investments that pay off. The longer Apple puts its cash in executive compensation without rewarding owners, the higher the risk that Karl Smith is right.
How many rich families do you know that sustained multi-generational wealth via the stock market? How many do it with real assets? It is worth thinking about.
Another statistics/auteur theory post -- causality
[the second in a very infrequent series]
From the LA Times:
The article doesn't quite come out and say it explicitly but I think it's fair to read this as claiming that there's a causal relationship between director's gender and the number of female characters, and that's really not feasible.
Gender of characters with speaking roles (which seem to be the ones we're talking about) are specified in the screenplay and, despite a widely held opinion to the contrary, directors don't write screenplays. This leaves us with two possibilities: writer/directors are confounding the data or the causal relationship runs the other way -- a screenplay with more female characters is more likely to be directed by a woman (perhaps because female directors are seen as less capable of handling male-heavy action films).
This question of causal direction has interesting implications for other auteurist analyses. How many of the common themes we see in a director's work are the result of the artist's personal vision and how many are the result of a certain director being assigned a certain type of picture (director as subgenre)?
Take Dial M for Murder. Thematically, it certainly feel like Hitchcock, but it was a successful stage play before it was a movie and pretty much all of the themes were in place before anyone even considered a motion picture version. In this one case isn't it reasonable to suggest that the themes caused the studio executives to pick Hitchcock rather than Hitchcock being responsible for these themes?
From the LA Times:
Cinema trends ebb and flow, but one facet of Hollywood moviemaking proving remarkably consistent is gender inequality, according to a study being released Monday by USC's Annenberg School for Communication & Journalism.
In a survey of the top 100-grossing movies of 2009 — including "Transformers: Revenge of the Fallen," "Harry Potter and the Half-Blood Prince" and "The Twilight Saga: New Moon" — researchers found that 32.8% of the 4,342 speaking characters were female and 67.2% were male, a percentage identical to that of the top-grossing movies of 2008.
"We see remarkably stable trends," said USC Annenberg associate professor Stacy L. Smith. "This reveals an industry formula for gender that may be outside of people's conscious awareness."
...
Researchers found that the sex of the storytellers had a significant effect on what appeared on-screen. In movies directed by women, 47.7% of the characters were female; in movies directed by men, fewer than a third of the characters were female. When one or more of the screenwriters was female, 40% of characters were female; when all the screenwriters were male, 29.8% of the characters were female.
The article doesn't quite come out and say it explicitly but I think it's fair to read this as claiming that there's a causal relationship between director's gender and the number of female characters, and that's really not feasible.
Gender of characters with speaking roles (which seem to be the ones we're talking about) are specified in the screenplay and, despite a widely held opinion to the contrary, directors don't write screenplays. This leaves us with two possibilities: writer/directors are confounding the data or the causal relationship runs the other way -- a screenplay with more female characters is more likely to be directed by a woman (perhaps because female directors are seen as less capable of handling male-heavy action films).
This question of causal direction has interesting implications for other auteurist analyses. How many of the common themes we see in a director's work are the result of the artist's personal vision and how many are the result of a certain director being assigned a certain type of picture (director as subgenre)?
Take Dial M for Murder. Thematically, it certainly feel like Hitchcock, but it was a successful stage play before it was a movie and pretty much all of the themes were in place before anyone even considered a motion picture version. In this one case isn't it reasonable to suggest that the themes caused the studio executives to pick Hitchcock rather than Hitchcock being responsible for these themes?
Sunday, November 27, 2011
Sad news
I think that the statement speaks for itself:
I have always respected Dr. Joyner (even if I often disagreed with him) and I am deeply sorrowed to hear of this tragedy. Best wishes to him and his family from the OE team.
My wife, Kimberly Webb Joyner, died this morning in her sleep from unknown causes. She was 41.
She leaves behind two little girls she loved more than anything, Katie, who turns 3 on New Year’s Eve, and Ellie, who was born June 21.
I have always respected Dr. Joyner (even if I often disagreed with him) and I am deeply sorrowed to hear of this tragedy. Best wishes to him and his family from the OE team.
Contradictions
Karl Smith is striking me as an optimist:
After all, he is demanding consistency here. I am not sure that humans are especially good at consistency. People often get quite annoyed at me when I drive the speed limit. I have the attitude that if we all want to drive faster on the road I am game, but I am unwilling to get a speeding ticket because local government cannot reach consensus on an appropriate speed limit.
In the same vein, I suspect that there can be a lot of daylight between the principle here and the application. That being said, I'd be delighted if we did adopt a more socialized medical system, purely for reasons of economic efficiency.
In any case, during the GOP Google debate there was a poll that asked GOP voters if someone should be denied medical treatment because they could not afford it. 80% said no. This is the end of the major question in my mind. If you answer no then you have de facto signed on to socialized medicine through some means.
After all, he is demanding consistency here. I am not sure that humans are especially good at consistency. People often get quite annoyed at me when I drive the speed limit. I have the attitude that if we all want to drive faster on the road I am game, but I am unwilling to get a speeding ticket because local government cannot reach consensus on an appropriate speed limit.
In the same vein, I suspect that there can be a lot of daylight between the principle here and the application. That being said, I'd be delighted if we did adopt a more socialized medical system, purely for reasons of economic efficiency.
Living with Mistakes the easy way -- larger points
Andrew Gelman fact-checks the New York Times:
For starters, creative destruction a big part of the story Brooks is telling, both in this column and in his body of work collectively. In this narrative, it's a tough process, but a healthy and fundamentally fair one. Here's the sentence that precedes Gelman's excerpt from Brooks: "Even if you make it to the top, it is very hard to stay there."
We can argue about the validity of this view, but there's no question that Brooks' incorrect statement supported this point while the corrected version undercuts it. There are millions of businesses and if success is truly determined solely by who has the best business model, the best execution and the best timing, a long run in the Fortune 500 (with shifts in markets and changes in management) would be a hell of a feat. The number we actually see would certainly imply something more at work (regulatory capture, anti-competitive practices, etc.).
So yes, I would call this a big deal with respect to the story Brooks is telling.
Perhaps more importantly, I have a problem with the distinction drawn here between statisticians and the rest of the world. It's true that the ability to sniff out suspect numbers and questionable findings is an essential part of being a good statistician, but it's also part being a good journalist (and a good engineer and a good accountant and any number of other professions).
As statisticians we need strong mathematical intuition and a heightened sense of how numbers relate to each other, but we don't have any claim to the urge to check the unlikely. David Brooks was simply being a bad journalist when he wrote that passage. It was not because of inability -- Brooks is smart and highly capable -- but because he didn't care enough to get it right. He know there would be no real consequences either for him or his paper if he got it wrong.
And a lack of consequences, my friends, makes living with your mistakes amazingly easy.
For example, David Brooks wrote the following, in a column called “Living with Mistakes”:I appreciate Gelman's sharp eye and I can understand why, being a nice guy, he tends to favor catch-and-release criticism, but I disagree sharply with his conclusions here.The historian Leslie Hannah identified the ten largest American companies in 1912. None of those companies ranked in the top 100 companies by 1990.
Huh? Could that really be? I googled “ten largest american companies 1912″ and found this, from Leslie Hannah:
No big deal: two still in the top 10 rather than zero in the top 100, but Brooks’s general point still holds. As Brooks said, we have to live with mistakes. This is more a comment on how a statistician such as myself will see a number and immediately feel the urge to check it.
...
Again, this is no criticism of Brooks—as a journalist, he’s of course more interested in good stories than in getting the details right (recall the notorious $20 dinner at Red Lobster). That’s ok. Storytelling is his job, numbers are mine.
For starters, creative destruction a big part of the story Brooks is telling, both in this column and in his body of work collectively. In this narrative, it's a tough process, but a healthy and fundamentally fair one. Here's the sentence that precedes Gelman's excerpt from Brooks: "Even if you make it to the top, it is very hard to stay there."
We can argue about the validity of this view, but there's no question that Brooks' incorrect statement supported this point while the corrected version undercuts it. There are millions of businesses and if success is truly determined solely by who has the best business model, the best execution and the best timing, a long run in the Fortune 500 (with shifts in markets and changes in management) would be a hell of a feat. The number we actually see would certainly imply something more at work (regulatory capture, anti-competitive practices, etc.).
So yes, I would call this a big deal with respect to the story Brooks is telling.
Perhaps more importantly, I have a problem with the distinction drawn here between statisticians and the rest of the world. It's true that the ability to sniff out suspect numbers and questionable findings is an essential part of being a good statistician, but it's also part being a good journalist (and a good engineer and a good accountant and any number of other professions).
As statisticians we need strong mathematical intuition and a heightened sense of how numbers relate to each other, but we don't have any claim to the urge to check the unlikely. David Brooks was simply being a bad journalist when he wrote that passage. It was not because of inability -- Brooks is smart and highly capable -- but because he didn't care enough to get it right. He know there would be no real consequences either for him or his paper if he got it wrong.
And a lack of consequences, my friends, makes living with your mistakes amazingly easy.
Saturday, November 26, 2011
"[T]he numbers show that wage inflation is — literally — the least of the problems when it comes to university cost inflation"
The quote comes from Felix Salmon and it's part of an excellent discussion (nicely summarized at Rortybomb). If you're interested in either education or the economy (where student debt is becoming a major factor), you should read all of the posts, but if I had to pick one point it would be this unbelievable projection cited by Malcolm Harris:
And while the proportion of tenure-track teaching faculty has dwindled, the number of managers has skyrocketed in both relative and absolute terms. If current trends continue, the Department of Education estimates that by 2014 there will be more administrators than instructors at American four-year nonprofit colleges.Also posted at Education and Statistics.
Probably the damnedest thing you'll see this weekend
And you think you have trouble getting out there for your morning jog...
Friday, November 25, 2011
Peak Life Expectancy
I am often skeptical of these claims that we will see the next generation have a shorter life expectancy as these claims require models. These models may be incorrect for a variety of reasons: misspecification, noise, shifting patterns of disease, unexpected technological improvements, and so forth.
But what was fascinating was the map in the article. The places in the United States where life expectancy is dropping are focused mainly in the Southeast. Now that distribution is, itself, interesting as the southeast has long had health issues: think of the classic stroke belt. Furthermore, it is an area of high inequality that has a climate that is very compatible with a sedentary lifestyle.
Contrast this with the California coast (and especially Los Angeles) where life expectancies are actually rising, or even New York city. Could it be that an urban lifestyle is actually life enhancing (both in terms of quantity and quality)?
So perhaps, instead, what we have is an ecological experiment to really try and understand these phenomena.
But what was fascinating was the map in the article. The places in the United States where life expectancy is dropping are focused mainly in the Southeast. Now that distribution is, itself, interesting as the southeast has long had health issues: think of the classic stroke belt. Furthermore, it is an area of high inequality that has a climate that is very compatible with a sedentary lifestyle.
Contrast this with the California coast (and especially Los Angeles) where life expectancies are actually rising, or even New York city. Could it be that an urban lifestyle is actually life enhancing (both in terms of quantity and quality)?
So perhaps, instead, what we have is an ecological experiment to really try and understand these phenomena.
Glycemic control and diabetes: today's evidence
This paper has the potential to be pretty important:
The article is free online but let me quote from the conclusion:
This is actually quite important. It is very difficult for patients to maintain low levels of blood glucose, with consequences in both quality of life and adverse events. Tight glycemic control, for example is the reason that some policy makers have concerns about diabetics driving (due to worries about hypoglycemic attacks).
Given the difficulty of getting diabetics to adhere to tight glycemic control (and concerns about issues like driving), perhaps we should be more cautious in pushing tight control? More interestingly, we should ask why this association seems non-linear, as it is obvious that objectively poor glycemic control is very cardiotoxic.
But this was a very interesting paper for highlighting what we do and not not know.
Intensive glycaemic control for patients with type 2 diabetes: systematic review with meta-analysis and trial sequential analysis of randomised clinical trials
The article is free online but let me quote from the conclusion:
Intensive glycaemic control does not seem to reduce all cause mortality in patients with type 2 diabetes. Data available from randomised clinical trials remain insufficient to prove or refute a relative risk reduction for cardiovascular mortality, non-fatal myocardial infarction, composite microvascular complications, or retinopathy at a magnitude of 10%. Intensive glycaemic control increases the relative risk of severe hypoglycaemia by 30%.
This is actually quite important. It is very difficult for patients to maintain low levels of blood glucose, with consequences in both quality of life and adverse events. Tight glycemic control, for example is the reason that some policy makers have concerns about diabetics driving (due to worries about hypoglycemic attacks).
Given the difficulty of getting diabetics to adhere to tight glycemic control (and concerns about issues like driving), perhaps we should be more cautious in pushing tight control? More interestingly, we should ask why this association seems non-linear, as it is obvious that objectively poor glycemic control is very cardiotoxic.
But this was a very interesting paper for highlighting what we do and not not know.
Tuesday, November 22, 2011
Things that make you wince science writing edition
I heard a brief discussion of Milgram's six degrees by KCRW's Sara Terry and NYT's Somini Sengupta. It wasn't pretty, but it did get me thinking about science stories that are consistently misreported. Two immediately jumped to mind:
Milgram's Small World
The Butterfly Effect
Now that we've got things started, I'm opening the floor to nominations. What science stories can you count on to make you wince?
Milgram's Small World
The Butterfly Effect
Now that we've got things started, I'm opening the floor to nominations. What science stories can you count on to make you wince?
Tax Levels
From Don Talyor:
I think that this is worth keeping in mind. A 21% of GDP budget target would already be a painful and difficult process to achieve with the headwinds we have already due to population aging. Lower levels require a really novel idea about how to reverse these headwinds.
But the options that might really shift the balance (immigration) seem to be out of favor right now.
If we adopted 21% of GDP as a future target for balancing the budget, we would be saying government spending will be less while the baby boomers are eligible for Medicare and Social Security than it commonly was when they were paying taxes to support these same programs. This will be very hard. Plans seeking balance at lower levels seem implausible.
I think that this is worth keeping in mind. A 21% of GDP budget target would already be a painful and difficult process to achieve with the headwinds we have already due to population aging. Lower levels require a really novel idea about how to reverse these headwinds.
But the options that might really shift the balance (immigration) seem to be out of favor right now.
Sunday, November 20, 2011
Toys for Tots -- reprinted, slightly revised
A good Christmas can do a lot to take the edge off of a bad year both for children and their parents (and a lot of families are having a bad year). It's not too late to pick up a few toys, drop them by the fire station and make some people feel good about themselves during what can be one of the toughest times of the year.
If you're new to the Toys-for-Tots concept, here are the rules I normally use when shopping:
The gifts should be nice enough to sit alone under a tree. The child who gets nothing else should still feel that he or she had a special Christmas. A large stuffed animal, a big metal truck, a large can of Legos with enough pieces to keep up with an active imagination. You can get any of these for around twenty or twenty-five bucks at Target;
Shop smart. The better the deals the more toys can go in your cart;
No batteries. (I'm a strong believer in kid power);*
Speaking of kid power, it's impossible to be sedentary while playing with a basketball;
No toys that need lots of accessories;
For games, you're generally better off going with a classic;
No movie or TV show tie-ins. (This one's kind of a personal quirk and I will make some exceptions like Sesame Street);
Look for something durable. These will have to last;
For smaller children, you really can't beat Fisher Price and PlaySkool. Both companies have mastered the art of coming up with cleverly designed toys that children love and that will stand up to generations of energetic and creative play.
* I'd like to soften this position just bit. It's okay for a toy to use batteries, just not to need them. Fisher Price and PlaySkool have both gotten into the habit of adding lights and sounds to classic toys, but when the batteries die, the toys live on, still powered by the energy of children at play.
If you're new to the Toys-for-Tots concept, here are the rules I normally use when shopping:
The gifts should be nice enough to sit alone under a tree. The child who gets nothing else should still feel that he or she had a special Christmas. A large stuffed animal, a big metal truck, a large can of Legos with enough pieces to keep up with an active imagination. You can get any of these for around twenty or twenty-five bucks at Target;
Shop smart. The better the deals the more toys can go in your cart;
No batteries. (I'm a strong believer in kid power);*
Speaking of kid power, it's impossible to be sedentary while playing with a basketball;
No toys that need lots of accessories;
For games, you're generally better off going with a classic;
No movie or TV show tie-ins. (This one's kind of a personal quirk and I will make some exceptions like Sesame Street);
Look for something durable. These will have to last;
For smaller children, you really can't beat Fisher Price and PlaySkool. Both companies have mastered the art of coming up with cleverly designed toys that children love and that will stand up to generations of energetic and creative play.
* I'd like to soften this position just bit. It's okay for a toy to use batteries, just not to need them. Fisher Price and PlaySkool have both gotten into the habit of adding lights and sounds to classic toys, but when the batteries die, the toys live on, still powered by the energy of children at play.
The most disgusting image I could come up with in the education reform debate
You can read my thoughts on dismembered puppy math over at Education and Statistics.
Statements that I violently disagree with
From Tyler Cowen via Scott Sumner:
Now do not get me wrong: I post a lot about Matt Yglesias because I think that he is a fine thinker and has some really nice points to make. But there is now way he is competitive to be the top progressive economist in the blogosphere. I can't claim to be an expert but, off the top of my head, I have have:
Noah Smith
Paul Krugman
Bradford Delong
Mark Thoma
Plus the Worthwhile Canadian Initiative folks occasionally drift into progressive territory and are always worth reading. And this is just off the top of my head and including blogs I read regularly. Again: the provocative policy thinker with good ideas and a solid grasp of economists label definitely applies to Yglesias. But I find him a very odd choice for #1 given the alternatives. If anything, I find him awfully centrist on economic matters, at times (which, I suppose, could explain the appeal).
Congratulations to Matt Yglesias on his new gig. He’s arguably the best progressive economist in the blogosphere, which isn’t bad given that he’s not an economist. I said “arguably” because Krugman’s a more talented macroeconomist. But Yglesias can address a much wider variety of policy issues in a very persuasive fashion. So he’s certainly in the top 5. His blog is the best argument for progressive policy that I’ve ever read. (But not quite persuasive enough to convince me.)
Now do not get me wrong: I post a lot about Matt Yglesias because I think that he is a fine thinker and has some really nice points to make. But there is now way he is competitive to be the top progressive economist in the blogosphere. I can't claim to be an expert but, off the top of my head, I have have:
Noah Smith
Paul Krugman
Bradford Delong
Mark Thoma
Plus the Worthwhile Canadian Initiative folks occasionally drift into progressive territory and are always worth reading. And this is just off the top of my head and including blogs I read regularly. Again: the provocative policy thinker with good ideas and a solid grasp of economists label definitely applies to Yglesias. But I find him a very odd choice for #1 given the alternatives. If anything, I find him awfully centrist on economic matters, at times (which, I suppose, could explain the appeal).
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