Opinion for the Court filed by Circuit Judge WILLIAMS.
This appeal arises out of a personal injury claim filed by Donald Raynor, Jr. and his parents against Merrell Pharmaceuticals, Inc., alleging that Merrell’s anti-nausea drug,
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Bendectin, caused Raynor’s birth defects. After a jury awarded $300,000 in compensatory damages, Merrell filed motions for judgment notwithstanding the verdict (“JNOV”) and for a new trial. The district judge granted the former based upon our decision in
Richardson v. Richardson-Merrell, Inc.,
Rule 50
Plaintiffs argue that JNOV under Federal Rule of Civil Procedure 50 (currently titled a “Judgment as a Matter of Law”) is an improper remedy for evidentiary errors at trial. Rather, according to plaintiffs, the only appropriate remedy for errors in the admissiоn of evidence is a motion for a new trial under Rule 59(a). On plaintiffs’ view JNOV is reserved for cases where the evidence presented was of insufficient weight to raise an issue for the jury.
Although plaintiffs concede that they failed to raise this issue before the district court, they argue that our decision in
Richardson,
We assume arguendo that two
post-Richardson
circuit court decisions adopting the view that evidence may not be excluded on a JNOV motion,
Douglass v. Eaton Corp.,
To be sure, the
Richardson
court upheld the grant of a JNOV motion in a ease factually similar to this one, and the opinion, although it discusses the evidence’s sufficiency, clearly rests on its inadmissibility.
Richardson,
Of course, if
Richardson
did create binding law establishing the proрriety of JNOV for admissibility errors, this panel would be bound by that precedent, despite the two intervening circuit court decisions that back plaintiffs’ position. Moreover, the rule re
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jecting resolution of an evidentiary issue on a motion for JNOV rests on imputed reliance; if the evidence had been excluded in the course of trial, the offering party might have offered a substitute. See
Jackson,
Plaintiffs argue that the district court inappropriately deemed their expert testimony inadmissible. We review the district court’s judgment for abuse of discretion.
Joy v. Bell Helicopter Textron, Inc.,
In Richardson this court held that similar evidence was inadmissible:
These three types of studies then — chemical, in vitro, and in vivo — cannot furnish a sufficient foundation for a conclusion that Bendectin caused the birth defects аt issue in this case. Studies of this kind, singly or in combination, are not capable of proving causation in human beings in the face of the overwhelming body of contradictory epidemiological evidence.
If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence.
In reliance on
Richardson,
the district court initially found plaintiffs’ evidence inadmissible under Rule 703. If we were to consider this case under Rule 703, nothing would compel us to deviate from our holding in
Richardson.
Plaintiffs make much of
Ambrosini v. Labarraque,
Plaintiffs argue, however, that our Rule 703 holding has no force in light of the Supreme Court’s decision in
Daubert.
While
Daubert
creates no obvious bar to applying Rule 703 as we have done in the past, it leaves obscurе the relation between that rule and the rule at issue in
Daubert,
Rule 702, whieh states that an expert may testify if the “scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue.” The
Daubert
Court found Rule 702 the “primary locus” of thе district court’s obligation to screen scientific evidence presented by expert testimony,
The Court in
Daubert
directed federal courts first to determine whether the proffered expert’s evidence is “scientific knowledge,” which it said required consideration of the following: (1) whether the theory or technique can be (or has been) tested; (2) whether the theory or tеchnique has been subject to peer review and publication; (3) the known or potential rate of error of the methodology; and (4) the general acceptance of the methodology.
Plaintiffs contend that the district court erroneously applied the principles of
Daubert
by focusing on the conclusions of their experts rather than on the methodology. They are correct that the Supreme Court stated that the inquiry should “focus ... solely оn principles and methodology, not on the conclusions that they generate.”
Id.
at 595,
None of the plaintiffs’ experts had published their conclusions regarding Bendeetin, nor had their work been subject to peer review (factor #2). See
Daubert v. Merrell Dow Pharmaceuticals, Inc.,
The experts’ methodology also suffers from “testing” problems (factor # 1). The only wаy to test whether data from nonhuman studies can be extrapolated to humans would be to conduct human experiments or to use epidemiological data. In fact, the experts’ conclusions have been tested by the latter method and have been found wanting. We do not believe that when the
Daubert
opinion directed courts to consider whether the “theory or technique ... can be (and has been) tested,”
Similarly, where sound epidemiological studies produce opposite results from nonepi-demiolоgical ones, the rate of error of the latter is likely to be quite high (factor # 3). Of course epidemiological evidence does not always trump the nonepidemiological. Here, however, plaintiffs make no serious argument that the epidemiological sample sizes have been too small to detect the relationship between Bendeetin and birth defects, a relationship that has been studied for hundreds of thousands of subjects.
In additipn to the
in vivo, in vitro,
and chemical data, plaintiffs put forth an expert, Dr. Thoman, who conducted a methodology called “differential diagnоsis,” an approach presumably designed to eliminate other possible causes of Raynor’s birth defect. Based upon this analysis, Dr. Thoman points to Bendeetin as the cause. He relied upon family history, parental background, genetic history, physical examination, pregnancy history, and toxicology. Nonetheless, Dr. Tho-man provided “no tested or testable theory to explain how, from this limited information, he was able to eliminate all other potential
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causes of birth defects.”
2
Daubert,
Nor can plaintiffs’ methodology be said to enjoy “general acceptance” (factor # 4). Here, we reiteratе our holding in
Richardson:
“Studies of this kind, singly or in combination, are not capable of proving causation in human beings in the face of the overwhelming body of contradictory epidemiological evidence.”
Finally, we note that even if the expert testimony were admissible under
Daubert,
it is unlikely that a jury could reasonably find it sufficient to show causation. The question of sufficiency would be a substantive rule under
Erie Railroad Co. v. Tompkins,
Because the district court was within its discretion in finding the plaintiffs’ expert evidence inadmissiblе under Rule 702, the judgment is
Affirmed.
Notes
. Plaintiffs attempt to have their cake and eat it too. On the one hand, they claim that the novelty of decisions limiting the district court's use of the JNOV justifies their failure to object. On the other, in their attempt to convince us to adopt the rule barring the use of JNOV for admissibility errors, they claim that the restrictive rule belongs to "[a] virtually unbroken string of federal appellate court decisions” since 1940.
We note that in order for a decision to qualify as supervening it must be decided after plaintiff's chance to raise the issue in the district court. In fact the district court granted the motion for a JNOV on April 13, 1993, well after both Douglass and Jackson, the later of which was decided January 4, 1993.
. Of course, an expert testifying simply that Ben-dectin was more likely than not the cause of the birth defects would not have to completely ''eliminate” every other possibility, no matter how small. Dr. Thoman's purported elimination of alternative exрlanations was, however, exceedingly vague, amounting to little more than a reference to "family history, ” examination of the child, "any laboratory tests," and "genetic studies.” App. 47.
. Plaintiffs argue that the appropriate substantive law is that of the District of Columbia, a premise that appears undisputed by defendants, at least so far as the record before us demonstrates. See
Raynor v. Richardson-Merrell, Inc.,
No. 83-3506,
