>Rather, the entire industry crucially depended on the false models. Indeed they changed the data to conform with the models, which is to say it was an intentional combination of using flawed models and using irrelevant historical data (see points 64-69 here for more).
So C(corruption) directly leads to B(bad model). She does not argue that A(everything falling apart)<-C anywhere in the piece. Silver is claiming that A<-B. He is not commenting about C. So while Silver's claim may not identify the absolute root cause, the author does not actually prove that his cause and effect analysis is flawed. If anything, she has shown that it may be incomplete.
Silver isn't just claming that A<-B. He is claiming that fixing B will fix A, and that fixing B is straightforward: just use good models.
mathbabe is saying that fixing B is not straightforward, because B<-C, and fixing C is very, very difficult. Bad models exist because people have incentives to make them bad.
She's also saying, I think, that fixing B by itself won't fix A, because B is not the root cause; C is. Fixing B without fixing C just means that C will manifest itself somewhere else, and A will still happen. In other words, there are many causal routes from C to A, and fixing B by itself only blocks one of them. So A<-C is true regardless of the state of B.
So C(corruption) directly leads to B(bad model). She does not argue that A(everything falling apart)<-C anywhere in the piece.
The point of the piece is that the financial meltdown stemmed from corruption, not from models. If this wasn't her point, then why else would she have written this piece?
She wrote this piece because she thinks he's only citing the proximate cause and not the ultimate cause. At least that's how it reads to me.
She doesn't appear to be disputing the idea that following bad models caused the crisis — instead, she just seems to be saying Silver missed the fact that the models were deliberately bad rather than simply a poor application of math.
A few quotes from the author herself:
"the entire industry crucially depended on the false models."
"Silver gives four examples what he considers to be failed models at the end of his first chapter, all related to economics and finance. But each example is actually a success (for the insiders) if you look at a slightly larger picture and understand the incentives inside the system."
She's not disputing that the models were false or even that acting in accordance with the models is what caused the crisis. She's disputing that this was accidental.
An argument doesn't have to contain a false statement to have no baring on the discussion.
And more generally it's quite possible for a thing to have multiple causes, and in this universe this is generally true for everything we witness. So if A causes C that doesn't mean that B can't also cause C "by definition". I'm not aware of any serious philosphical framework that says that events must have only a single cause, though many philosophers from Aristotle onwards[1] but great stock in the "final cause" of things, but that would be either "God" or "The Big Bang" depending on your religion or lack thereof and nobody was arguing for those.
And as an aside, the words "by definition" in an argument that isn't on it's surface about definitions is generally a bit of a red flag.[2]
She does not prove that claim, though. She argues that corruption causes bad models. For Silver's cause and effect analysis to be incorrect, she needed to prove that the inaccurate models had absolutely nothing to do with the financial meltdown.
The models can be part of the meltdown without really being a cause.
If I choose to shoot you with a gun, and have a variety of appropriate guns, it is not the fault of the specific gun chosen that it was used to kill you. I had motive, opportunity, and alternate means available.
"For Silver's cause and effect analysis to be incorrect, she needed to prove that the inaccurate models had absolutely nothing to do with the financial meltdown."
If I smashed your head in with a hammer, would people claim the hammer was the cause of your death? Is "hammer caused death" the end of the story, or even particularly important to the related series of causes and effects?
She's arguing that it's not, that Silver's cause and effect analysis is irrelevant because his purported cause is purely incidental. Intentionally inaccurate models were simply an instrument designed to further the self-interest of individuals.
(And further, she doesn't need to provide a "proof" to make this claim. But she does offer a compelling argument.)
She states:
>Rather, the entire industry crucially depended on the false models. Indeed they changed the data to conform with the models, which is to say it was an intentional combination of using flawed models and using irrelevant historical data (see points 64-69 here for more).
So C(corruption) directly leads to B(bad model). She does not argue that A(everything falling apart)<-C anywhere in the piece. Silver is claiming that A<-B. He is not commenting about C. So while Silver's claim may not identify the absolute root cause, the author does not actually prove that his cause and effect analysis is flawed. If anything, she has shown that it may be incomplete.