Nathan Schachtman appropriately refers to the way in which “dicta infects Daubert” in his latest blogpost Siracusano Dicta Infects Daubert Decisions. Here the “dicta” (or dictum?) is a throwaway remark on (lack of) statistical significance and causal inference by the Supreme Court, in an earlier case involving the drug company Matrixx (Matrixx Initiatives, Inc. v. Siracusano). As I note in my post of last Feb,
“the ruling had nothing to do with what’s required to show cause and effect, but only what information a company is required to reveal to its shareholders in order not to mislead them (as regards information that could be of relevance to them in their cost-benefit assessments of the stock’s value and future price).”(See “Distortions in the Court”)
It was already surprising that the Supreme Court took up that earlier case; the way they handled the irrelevant statistical issues was more so.
My question now is this: Doesn’t it encourage the introduction of opinions irrelevant to the case at hand, case X, when those opinions are permitted to be used as evidence in a subsequent case Y (even though the opinions, being irrelevant to case X, are not supposed to establish any precedent for Y)? Or am I misunderstanding? I hope Schachtman will weigh in.
Here is Schachtman’s sum-up regarding the case:Memorandum in Support of Separate Pretrial Order No. 8933, Cheek v. Wyeth Pharm. Inc.
In Cheek, Judge Harvey Bartle rejected a Rule 702 challenge to plaintiffs’ expert witness’s opinion. I confess that I do not know enough about the expert witness’s opinion or the challenge to assess Judge Bartle’s conclusion. Judge Bartle, however, invoked the Matrixx decision for the dubious proposition that:
‘Daubert does not require that an expert opinion regarding causation be based on statistical evidence in order to be reliable. Matrixx Initiatives, Inc. v. Siracusano, 131 S. Ct. 1309, 1319 (2011). In fact, many courts have recognized that medical professionals often base their opinions on data other than statistical evidence from controlled clinical trials or epidemiological studies. Id. at 1320.’
… The Cheek decision is a welter of non-sequiturs. The fact that in some instances statistical evidence is not necessary is hardly a warrant to excuse the lack of statistical evidence in every case. The truly disturbing gaps in reasoning, however, are not scientific, but legal. Siracusano was not a “Daubert” opinion; and Siracusano does not, and cannot, support the refusal to inquire whether statistical evidence was necessary in a causation opinion, in main part because causation was not at issue in Siracusano.
There are a couple of different cases here; I hope the interested reader will sift through some of the background links.
Filed under: PhilStatLaw, Statistics Tagged: Cause and effect, Daubert, judicial opinion, Matrixx, Nathan Schachtman
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