Now it is 2015, the case is Murray v. Motorola, Inc., 4/ and the proffered evidence is expert testimony that cell phones cause (or raise the risk of) brain cancer. The methods used to form or support this opinion or related ones range from what the court calls “WOE” (the expert says, I thoroughly assessed the “weight of evidence”), to “PDM” (I considered the evidence of causation pragmatically, with the “Pragmatic Dialog Method”), to “a literature review” (I read everything I could find on the subject), to “laboratory experiments” (I conducted in vitro exposure of cells, with results that may not have been replicated), and to “experience as a toxicologist and pharmacologist” to show that “it is generally accepted to extrapolate findings from in vitro studies in human and mammalian cells to predict health effects in humans.”
The trial judge, Frederick H. Weisberg, ruled much of this testimony admissible on the theory that regardless of the extent to which the conclusions are within the mainstream of scientific thinking, the “methods” behind them were generally accepted in ascertaining carcinogenicity. He chastised the defense for “repeatedly challeng[ing] plaintiffs' experts on the ground that their conclusions and opinions are not generally accepted.” As he construed Frye, “[e]ven if 99 out of 100 scientists come out on one side of the causation inference, and only one comes out on the other, as long as the one used a ‘generally accepted methodology,’ Frye allows the lone expert to testify for one party and one of the other ninety-nine to testify for the opposing party.” Having placed himself in this box, Judge Weisberg asked the Court of Appeals to let him out, writing that “most, if not all, of Plaintiffs' experts would probably be excluded under the Rule 702/Daubert standard based on the present record” and granting the defendants' request to allow them to appeal his ruling immediately.
Defendants then convinced the Court of Appeals to jump in. Normally, the appellate court would review only the final judgment entered after a trial. In Murray, it granted an interlocutory appeal on the evidentiary ruling. Not only that, but it agreed to sit en banc, with all nine judges participating rather than to act through a normal panel of three randomly selected judges.
The question before the en banc court is thus framed as whether to replace the jurisdiction’s venerable Frye standard with the approach sketched in Daubert v. Merrell Dow Pharmaceuticals. 5/ Daubert changes the focus of the judicial inquiry from whether a theory or technique is generally accepted to whether it is scientifically valid. (see Box: What Daubert Did).
|But does Frye really require Judge Weisberg to accept evidence that Daubert excludes in this case? The case, I shall argue, is not about Daubert versus Frye. It is about methodology versus conclusion. The judge's construction of Frye as sharply confined to “methodology” is what makes it impossible for him to reject as inadmissible the theory that cell phones cause brain cancers even if it is plainly not accepted among knowledgeable scientists. And that is just as much a problem under Daubert as it is under Frye. Daubert specifically states that the subject of the inquiry “is the scientific validity ... of the principles that underlie a proposed submission. The focus, of course, must be solely on principles and methodology, not on the conclusions that they generate.” 6/ Judge Weisberg decided that principles or putative methodologies like WOE, PDM, literature review, extrapolation from in vitro experiments, and experience are all generally accepted among scientists as a basis for inferring carcinogencity. But if this is correct, and if it insulates claims of general causation from scrutiny for general acceptance under Frye, then it does the same under Daubert (as originally formulated). 7/ Surely, weighing all the relevant data, being pragmatic, studying the literature, considering experiments, and using experience is what scientists everywhere do. They do it not out of habit, but because these things tend to lead to more correct conclusions (and less criticism from colleagues) than the alternatives of not weighing all the data, being doctrinaire, ignoring the literature, and so on.|
The problem with the toxic tort cases like Murray is that the line between “method” and “conclusion” is difficult to draw, and Judge Weisberg draws it in the wrong place. Although his opinion cites to (the first edition of) Wigmore on Evidence: Expert Evidence, it ignores the warning (in § 6.3.3(a)(1) of the second edition and § 5.2.3 of the first edition) that
The opinion in Murray also overlooks the more extended analysis in Wigmore of why causation opinions in toxic tort cases should be considered theory rather than conclusions within the meaning of Frye. 9/ It would make no sense to ask whether psychologists generally accept the proposition that Marsden correctly measured the defendant's blood pressure or correctly applied some formula or threshold that indicated deception. Such case-specific facts do not appear before any general scientific community for scrutiny. On the other hand, whether elevated blood pressure is associated with deception, how it can be measured, and whether a formula or threshold for concluding that the defendant is deceptive or truthful are trans-case propositions that should be part of normal scientific discourse.
The same is true of claims of carcinogenicity. Whether cell phones can cause brain cancer at various levels of exposure are trans-case propositions that stimulate scientific dialog. The Frye test can function just as well (or as poorly) in vetting expert opinions that exposure can cause cancer as in screening a psychologist's opinion that deception can cause a detectable spike in blood pressure. In sum, denominating trans-case conclusions that have been or could be the subject of scientific investigation and controversy as "conclusions" that are beyond the reach of either Frye or Daubert is a category mistake.
There is another way to make this point. Given all the usual reasons to subject scientific evidence to stricter-than-normal scrutiny, courts in Frye jurisdictions need to consider whether it is generally accepted that the body of scientifically validated findings on which the expert relies is sufficient to justify, as scientifically reasonable, the trans-case conclusion. Thus. the Ninth Circuit Court of Appeals in Daubert originally reasoned — on the basis of Frye — that in the absence of some published, peer-reviewed epidemiological study showing a statistically significant association, the causal theories (whether they are labelled general premises or specific conclusions) of plaintiffs’ expert were inadmissible. The court determined that the body of research, namely, “the available animal and chemical studies, together with plaintiffs' expert reanalysis of epidemiological studies, provide insufficient foundation to allow admission of expert testimony to the effect that Bendectin caused plaintiffs' injuries.” 10/ It was appropriate — indeed, necessary — to consider all the “available ... studies,” but under Frye, there still had to be general acceptance of the proposition that drawing an inference of causation from such studies was generally accepted as scientifically valid. Gussying up the inferential process as a WOE analysis (or anything else) cannot alter this requirement.
Whether or not the Court of Appeals switches to Daubert, it should correct the trial court's blanket refusal to consider whether the theory that cellphones ever cause brain cancer at relevant exposure levels is generally accepted. General acceptance may not be determinative under Daubert, but it remains important. Whether the inquiry into this factor is compelled and conclusive under Frye or inevitable and influential under Daubert, it should not be skewed by a misconception of the scope of that inquiry. In the end, the courts in Murray should realize that
- Ann E. Marimow, D.C. Court Considers How To Screen Out ‘Bad Science’ in Local Trials, Wash. Post, Nov. 24, 2015
- 293 F. 1013 (D.C. Cir. 1923).
- Id. at 1014.
- No. 2001 CA 008479 B (D.C. Super. Ct.), available at http://apps.washingtonpost.com/g/page/local/dc-court-of-appeals-notice-of-appeal/1889/
- 509 U.S. 579 (1993).
- Id. at 594–95 (emphasis added).
- In General Electric Co. v. Joiner, 522 U.S. 136 (1997), the Supreme Court blurred the distinction between methodology and conclusion, and Congress later amended Rule 702 to incorporate this shift. The result is that in federal courts, it is less important to draw a better line than the one in Murray and Ibn-Thomas. See David H. Kaye, David A. Bernstein, and Jennifer L. Mnookin, The New Wigmore: A Treatise on Evidence: Expert Evidence § 9.2.2 (2d ed. 2011).
- Id. § 6.3.3(a)(1).
- Id. § 9.2.3(b).
- Daubert v. Merrell Dow Pharms., Inc., 951 F. 2d 1128, 1131 (9th Cir. 1991).
- Kaye et al., supra note 7, § 7.2.4(a).