509 U.S. 579, 592 (1993)
Two minors brought suit against Merrell Dow Pharmaceuticals, claiming they suffered limb reduction birth defects because their mothers had taken Bendectin, a drug prescribed for morning sickness to about 17.5 million pregnant women in the United States between 1957 and 1982.1
Limb reduction defects occur in fewer than one birth out of every 1000.2 Scientists do not know the mechanism by which any teratogen causes such defects.3 The plaintiffs offered testimony from three groups of experts.4 One group proposed to testify to a statistical link between Bendectin ingestion during pregnancy and limb reduction defects based on reanalyses of published studies that had reported no such association.5 A second group proposed to testify that Bendectin causes limb reduction defects in humans because it causes such defects in laboratory animals.6 A third group proposed to testify based on the similarity of Bendectin's chemical structure to other drugs suspected of causing birth defects.7
The district court granted summary judgment to Merrell Dow after excluding the plaintiffs' expert testimony.8 The Ninth Circuit affirmed that decision.9 The Supreme Court granted certiorari, reversed, and remanded for consideration under Federal Rule of Evidence 702.10
On remand, the Ninth Circuit examined the affidavits and prior trial testimony of the plaintiffs' experts.11 None of the experts had studied the effect of Bendectin on limb reduction defects before being hired to testify in this or related cases.12 None had published his work on Bendectin in a scientific journal.13 The only review their work had received was by judges and juries.14
Plaintiffs' epidemiological experts made vague assertions of a statistically significant relationship between Bendectin and birth defects but did not state that the relative risk exceeded two.15 With the exception of Dr. Palmer, the remaining experts were willing to testify only that Bendectin is capable of causing birth defects.16 Dr. Palmer alone was willing to testify that Bendectin did cause the limb defects in each of the children, based on his review of the plaintiffs' medical records and his conclusion that Bendectin is a teratogen.17
Whether the Ninth Circuit should remand the case to the district court for the initial determination of admissibility under the standard announced by the Supreme Court?18
Although district courts ordinarily make the initial determination of admissibility of expert testimony, an appellate court may decide the issue itself when the district court has already ruled on admissibility under a prior standard, summary judgment was granted, and the interests of justice and judicial economy favor resolution without remand.19
No. The district court had already excluded the plaintiffs' expert testimony and granted summary judgment.20 The Ninth Circuit could review whether that judgment could be sustained under the new Daubert standard without remanding because the record permitted a determination that the evidence was inadmissible as a matter of law.21
The Ninth Circuit properly resolved the admissibility questions itself rather than remanding to the district court.22
Whether plaintiffs were required to come forward with evidence on summary judgment because the moving party's expert affidavit was itself inadmissible?23
Yes. Plaintiffs bore the burden of proving causation.26 Merrell Dow had only to point to the absence of a genuine issue of material fact regarding causation.27 The admissibility of Merrell Dow's own expert affidavit was irrelevant to whether plaintiffs had adduced sufficient admissible evidence to survive summary judgment.28
Plaintiffs were required to come forward with admissible evidence creating a genuine issue of material fact on causation.29
Whether the testimony of plaintiffs' experts reflects scientific knowledge derived by the scientific method?30
Under Federal Rule of Evidence 702, expert scientific testimony is admissible only if it is based on scientifically valid principles derived by the scientific method.31 This may be shown by proof that the expert's work grew out of independent pre-litigation research, was subjected to peer review and publication, or is supported by objective validation from a learned treatise or similar source.32
No. None of the plaintiffs' experts had studied the effect of Bendectin on limb reduction defects before being hired to testify in this or related cases. None had published his work on Bendectin in a scientific journal. The only review their work received was by judges and juries. The experts offered only unadorned assertions that their methodology comported with standard scientific procedures without pointing to any external validating source.33
The testimony of plaintiffs' experts does not reflect scientific knowledge derived by the scientific method and is inadmissible under the first prong of Rule 702.34
Related opinions on this issue
Chief Justice Rehnquist joined the portions of the Supreme Court opinion holding that the Frye rule did not survive the Federal Rules of Evidence.35 He cautioned against the majority's abstract general observations on reliability and scientific validity.36 He noted that the Court was venturing far afield from its expertise by parsing terms like scientific knowledge and falsifiability without applying them to specific testimony.37
He would have decided only the questions presented rather than imposing broad new gatekeeping obligations that risk turning judges into amateur scientists.38
Whether the testimony of plaintiffs' experts is relevant to the task at hand by advancing a material aspect of the case?39
Under the second prong of Federal Rule of Evidence 702, expert testimony must fit the case by logically advancing a material aspect of the proposing party's claim.40 In a toxic tort case this requires a valid scientific connection showing that the substance more likely than not caused the plaintiff's specific injury under the governing substantive law.41
No. Plaintiffs' epidemiological experts made only vague assertions of a statistically significant relationship.42 They did not claim that Bendectin more than doubled the risk of limb reduction defects.43 The remaining experts testified only that Bendectin is capable of causing birth defects rather than that it caused the plaintiffs' injuries.44 Under California tort law this evidence would not assist the trier of fact because it fails to satisfy the more-likely-than-not standard.45
The testimony of plaintiffs' experts does not satisfy the fit requirement and is inadmissible under the second prong of Rule 702.46
Whether plaintiffs' epidemiological experts claim that ingestion of Bendectin more than doubles the risk of limb reduction birth defects?47
To prove causation under California tort law by statistical evidence, plaintiffs must show that the relative risk of limb reduction defects from Bendectin exceeds two.48 Only then can it be said that Bendectin more likely than not caused the injuries given the background rate of one per thousand births.49
No. Plaintiffs' epidemiological experts made vague assertions that there is a statistically significant relationship between Bendectin and birth defects.50 None stated that the relative risk is greater than two.51 Because the background rate of limb reduction defects is one per thousand births, a relative risk exceeding two is required to satisfy the more-likely-than-not standard of California tort law.52 The studies therefore tend to disprove rather than prove legal causation.53
Plaintiffs' epidemiological experts do not claim that ingestion of Bendectin more than doubles the risk of limb reduction birth defects.54