dissenting:
In Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993), the Supreme Court held that in order to be admissible in a ease such as this expert testimony must both “be ‘scientific ... knowledge’ ” and “ ‘assist the trier of fact to understand the evidence or to determine a fact in issue.’ ” 509 U.S. at 590-91, 113 S.Ct. at 2795 (quoting Fed.R.Evid. 702). The Court explained that
in order to qualify as “scientific knowledge,” an inference or assertion must be derived by the scientific method. Proposed testimony must be supported by appropriate validation — i.e., “good grounds,” based on what is known. In short, the requirement that an expert’s testimony pertain to “scientific knowledge” establishes a standard of evidentiary reliability.
509 U.S. at 590, 113 S.Ct. at 2795. The Court assigned to the trial court the task of “determining] at the outset, pursuant to Rule 104(a), whether the expert is proposing to testify to (1) scientific knowledge that (2) will assist the trier of fact to understand or determine a fact in issue.” Id. at 592, 113 S.Ct. at 2796. The court’s determination “entails a preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and of whether that reasoning or methodology properly can be applied to the facts in issue.” Id. at 592-93, 113 S.Ct. at 2796. The district court here made such an assessment on remand. After conducting the detailed inquiry required by this court in Ambrosini v. Labarraque, 966 F.2d 1464, 1468- 69, 1471 (D.C.Cir.1992), the district court found both Strom’s and Goldman’s testimony inadmissible. And little wonder. Neither expert offered anything resembling a scientifically valid basis for his opinion that ingestion of Depo-Provera, or of progestins in general, has a causal relationship to cleft lip, cleft palate or the other birth defects Teresa Am-brosini suffered. The district court therefore properly held the experts’ testimony inadmissible and this panel should affirm the court’s holding.
Both Strom and Goldman purported to base their opinions largely on two indepen*142dent studies conducted by Greenberg and Matsunaga. See App. 209, 245; 352-54, 358. Yet each conceded during the lengthy evi-dentiary hearing below that neither study found a significant causal link between pro-gestins and increased incidence of cleft lip or palate. See, e.g., App. 250 (Strom agreeing that when Greenberg study “looked at that issue, progestins and hormonal support, they were unable to find a statistically significant increased incidence of birth defects”); 360 (Goldman agreeing that Greenberg study “did not find a statistically significant excess of cleft lip-palate in children born to mothers who received only progestin”); 255-56 (Strom agreeing that Matsunaga study “said in fact” there was no “causal” association between hormone therapy and birth defects “because they established, to their satisfaction, that the drug was given after the defects had already occurred”); 431 (Goldman admitting that Matsunaga study “concluded that while statistically there was an increased association between Provera and cleft lip-cleft palate ... given the importance of timing and the fact that they knew when conception had taken place, they were able to establish that the drug was given after the defects had already occurred; therefore the association was not causal”).
Goldman also claimed to rely on two studies by Heinonen and Newman. App 346. But again, responding to specific questions, he conceded that neither study “found a statistically significant increased risk for Prov-era causing the type of birth defects that Teresa Ambrosini has,” neither of “cleft lip and palate” nor of “the entire picture of what Teresa Ambrosini has.” App. 347-48.1 In fact, he ultimately conceded he was not “aware of any review article published in any peer-reviewed journal that ... has said that progestins do cause cleft lip-cleft palate or any of the defects that Teresa Ambrosini has,” App. 404-05, and that he did not “recall” “any article ... that shows an association between Provera or Depo-Provera and an increased incidence of-cleft palate in humans,” App. 420.2
Further, each expert acknowledged, but discounted, the existence of published studies of progestins (Lammer study) and Provera in particular (Katz study and Yovich study) that found no causal relationship between those substances and cleft lip or palate, App. 257, 259 (Strom); App. 350-51 (Goldman), and three other published studies (Warkany study, Wilson & Brent study, Sehardein study) that found no evidence that progestins cause nongenital birth defects. App. 295 (Strom); App. 402-04 (Goldman).
Thus, in the end, we are left with no basis for the two experts’ opinions except their own individual study. Strom testified that he formed his opinions “look[ing] at the totality of the data” in the published studies without “looking at the much larger literature of people expressing opinions in the literature.” App. 260. This “methodology” produced conclusions inconsistent with those of the studies’ authors but supportive of the appellants’ case. Strom claimed to base his opinions on the data of the “positive” studies only, rejecting the negative studies’ data as “too Small,” App. 266, but the two “positive” studies he identified do not support a causal relationship between Depo-Provera and any of the specific birth defects Teresa Ambrosini suffered. See App. 300, 293 (Heinonen study found association of progestins with “heart defects” but “didn’t see an association between Provera and one specific defect”); App. 257 (Lammer study “didn’t find an in*143creased incidence of cleft lip, cleft palate or any of the other malformations that Teresa Ambrosini has with respect to progestin use” but only of “other malformations”). Thus, his opinions are not, as he claimed, supported by those studies’ data nor, judging from his testimony, .by any “appropriate validation.” Daubert, 509 U.S. at 590, 113 S.Ct. at 2795. And Goldman’s opinions fare no better.
Goldman described his methodology as follows: “[L]ike anything else, it’s the preponderance of an argument. It’s the argument in favor against the argument against, and this is what everyone else does.” App. 429. The district court concluded: “The problem with this methodology is that it does not satisfy Daubert.” App. 89. I agree — as apparently does the majority. See Maj. Op. at 137.
The majority nevertheless attempts to defend Goldman’s baseless opinion on several grounds. First, the majority accuses the district court of “‘reifying] heavily on an isolated comment’ about balancing.” Maj. Op. at 137 (quoting Mendes-Silva v. United States, 980 F.2d 1482, 1487 (D.C.Cir.1993)). The district court had no choice, however, given the lack of any other support (such as the studies and their data on which Goldman purported to rely), but to focus on Goldman’s own characterization of his methodology— and, given the nature of his characterization, to reject the methodology.
The majority also observes that Goldman himself explained that he used the “traditional methodology of experts in the field.” Maj. Op. at 137, 138-139. Indeed he so stated repeatedly — without ever identifying or describing the methodology except as noted above. If such conclusory statements must be accepted at face value, as the majority suggests,' the Daubert standard becomes meaningless. Cf. Daubert v. Merrell Dow Pharmaceuticals, Inc., 43 F.3d 1311, 1319 (9th Cir.) (Daubert II) (summarily dismissing “experts’ unadorned assertions that the methodology they employed comports with standard scientific procedures”), cert. denied, — U.S. -, 116 S.Ct. 189, 133 L.Ed.2d 126 (1995).
The majority similarly suggests that Goldman’s “significant stature and expertise in the area of birth defects” shows that he “employed a scientifically valid methodology or mode of reasoning.” Maj. Op. at 139-140. Daubert, however, requires that the expert’s testimony in a specific case satisfy “a standard of evidentiary reliability,” 509 U.S. at 590, 113 S.Ct. at 2795 — the expert’s general reputation does not meet that requirement. Cf. Daubert II, 43 F.3d at 1319 (“We’ve been presented with only the experts’ qualifications, their conclusions and their assurances of reliability. Under Daubert, that’s not enough.”).
The majority acknowledges the “resemblance” of Goldman’s testimony to “that proffered in Richardson [v.Richardson-Merrell, Inc., 857 F.2d 823, 832 (D.C.Cir.1988), cert. denied, 493 U.S. 882, 110 S.Ct. 218, 107 L.Ed.2d 171 (1989) ], which held inadmissible expert testimony alleging causation of a drug in a birth defects case.” Maj. Op. at 138. I find both Goldman’s and Strom’s testimony strikingly similar to the expert’s in Richardson. At issue in Richardson was whether “Bendeetin,” an anti-nausea drug ingested by Mrs. Richardson during her pregnancy, had caused her child’s birth defects. This court upheld the trial court’s ruling that the plaintiffs’ expert’s opinion “lacked ‘a genuine basis, in or out of the record,’ and that his ‘theoretical speculations’ could not sustain the Richardsons’- burden of proving causation.” 857 F.2d at 829 (quoting Richardson v. Richardson-Merrell, Inc., 649 F.Supp. 799, 803 (D.D.C.1986)). In holding the expert’s opinion inadmissible, we noted in particular that he had (1) “admitted that no one who has published work on Bendeetin has concluded that there is a statistically significant association between Bendeetin and limb defects of the type at issue in this case,” (2) reached “a statistically significant result” “[o]nly by recalculating the data” from published studies, and (3) rejected studies that “had been published in peer-reviewed scientific journals,” while he himself “neither published his recalculations nor offered them for peer review.” Id. at 831. As is clear from the foregoing discussion, Goldman’s and Strom’s opinions are subject to the same sort of criticisms. Nevertheless, the majority at*144tempts to distinguish the two cases on several grounds.
First, the majority states: “Dr. Goldman never conceded that his methodology was not generally accepted in his field ...” Maj. Op. at 138.3 Neither did the expert in Richardson and after Daubert it is clear that the methodology need not be generally accepted. See Daubert, 509 U.S. at 589, 113 S.Ct. at 2794-95 (rejecting “generally accepted” standard as “austere” and “absent from and incompatible with the Federal Rules of Evidence”). What the Richardson expert did was to “acknowledgef ] the necessity of a statistically significant association between the drug and its effect in human populations,” to “admit[ ] that no one who has published work on Bendeetin has concluded that there is a statistically significant association between Bendeetin and limb reduction defects of the type at issue in this case,” and, apparently, to concede that “[o]nly by recalculating the data was [he] able to obtain what he deems a statistically significant result.” 857 F.2d at 830-31. There is no dispute here (nor can there be) that some “significantly statistical association” is required between Depo-Provera and Teresa’s particular birth defects. See, e.g., App. 210 (Strom), 328 (Goldman). Further, as detailed above, each expert here conceded that no such association had been shown. See supra pp. 141-142.
The majority next asserts that “unlike in Richardson, there is no ‘overwhelming body of contradictory epidemiological evidence to Dr. Goldman’s conclusion.’ ” Maj. Op. at 138 (quoting 857 F.2d at 830). In Richardson, we affirmed our earlier observation, in Ferebee v. Chevron Chem. Co., 736 F.2d 1529, 1534 (D.C.Cir.), cert. denied, 469 U.S. 1062, 105 S.Ct. 545, 83 L.Ed.2d 432 (1984), “that courts should be very reluctant to alter a jury’s verdict when the causation issue is novel and lstand[s] at the frontier of current medical and epidemiological inquiry ’ ” provided that “experts are willing to testify to causation in such situations and their methodology is sound.” 857 F.2d at 832 (quoting Ferebee, 736 F.2d at 1534; alteration and emphasis by Richardson court). The court then noted: “The case before us, however, is not like Ferebee.’’ Nor is this one. While the contradictory evidence here may not be “overwhelming” as in Richardson, it is substantial. The “frontier” of the inquiry was crossed long ago and “the published results must be given their just due.” Id. at 832. In any event, as Richardson observed, an expert’s methodology must always be “sound” even on the “frontier.” That was not the case here.
Finally, the majority claims that “unlike the doctor in Richardson, whose opinions were based on his own unreviewed recalculations of data gathered by others, 857 F.2d at 831, Dr. Goldman examined the relevant studies, noted their limitations, and followed a methodology accepted by teratologists to reach his conclusion.” Maj. Op. at 138-139. While the witnesses here did not admit recalculating data,4 neither did they identify the specific data on which they relied nor explain why their interpretations of the data differ from those in all of the published studies. In addition, neither expert ever described a specific methodology that can be reasonably characterized as “accepted.”
In sum, the appellants’ expert testimony here was very much like the unfounded testimony in Richardson and falls far short of Daubert’s “scientifically valid” standard for admissibility. On remand, the district court *145ordered the expert witnesses “to produce the articles and other data which have formed the basis of their opinions,” App. 24, as suggested by the panel in Ambrosini I,5 and conducted a lengthy hearing as part of the “preliminary assessment” required by Daubert, see 509 U.S. at 592-93, 113 S.Ct. at 2796-97. In the end, after the two experts discounted (or ignored) all of the published and peer-reviewed opinions, while offering no data supporting a positive statistically significant association, much less a causal relationship, between Depo-Provera and the specific birth defects Teresa Ambrosini suffered, the only ‘fijases” left for the two experts’ opinions were Strom’s “totality of the data” and Goldman’s “preponderance of an argument” standards. Based on these wispish methodologies, neither Strom nor Goldman could offer a reliable, scientific opinion on general causation.6 Thus, the district court was required to hold their opinions inadmissible and this court has no rational alternative but to follow Richardson and Daubert and to affirm that holding.7 Because the majority opts otherwise, I dissent.
. Goldman did testify regarding the birth defects that were found in the two studies, "like cardiac defects, limb defects and several others,” that the researchers "did have enough if they grouped the data all together to say that Provera — no, no— progestins produced a significant malformation rate in the total amount.” App. 348^-9. This "significant malformation rate” tells us nothing, however, of the relationship between progestins and cleft lip or palate, which, as the majority concedes, the studies "did not specifically discuss ... because 'they didn’t have enough cases of cleft lip and cleft palate to say one way or the other.' " Maj. Op. at 139 n.13 (quoting Goldman at App. 348).
. Goldman also cited a letter to the editor of the “Medical Journal of Australia” that apparently found some association between"progestogen-es-trogen” combinations and cleft lip and palate. See App. 362-68. Goldman testified, however, that the letter was based on an "uncontrolled study" and as such "might give you some idea” but would not yield a result that is "significant statistically.” App. 365.
. The majority asserts that this was "a point that the Ambrosini I court suggested was dispositive in Richardson." Maj. Op. at 138. Ambrosini I, however, characterized Richardson as holding that the expert's testimony "was inadmissible under Rule 703 because he acknowledged that the data underlying his opinion was not of a type reasonably relied on by experts in the field.” 966 F.2d at 1469 (emphasis added); see Richardson, 857 F.2d at 829 ("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.”).
. When asked whether he recalculated statistics, Strom replied: "Generally if the data — if the calculations were in the paper, I preferred to take the calculations of the author. The only time we did calculations of our own, and there were some where we did, where we had questions we were looking at, the data were presented by the authors but they did not do the calculations." App. 224.
. The Ambrosini I panel stated:
[T]he court could have required Dr. Strom and Dr. Goldman to disclose the bases for their opinions so that it could determine whether the opinions had an adequate foundation (i.e. whether they were based on information that experts in the field would reasonably rely on in determining whether a particular drug causes birth defects). Only then could the court determine whether the affidavits were admissible under Rule 703. A court must know the basis for an expert's opinion before it can determine that the basis is not of a type reasonably relied on by experts in the field.
966 F.2d at 1469.
. Because there was no preliminary showing of general causation — by either expert — it is irrelevant whether Goldman adequately eliminated other possible causes, as the majority maintains, to establish specific causation. See Maj. Op. at 140. As the district court observed, Strom conceded he was not qualified to testify on the latter. See App. 31. Nor need we consider whether Strom's testimony "fit” the plaintiff's case, that is, in the words of rule 702, whether it would "assist the trier of fact to understand the evidence or to determine a fact in issue,” — a proposition the district court rejected. See App. 31-33; see also Daubert, 509 U.S. at 591-92, 113 S.Ct. at 2796 ("study of the phases of the moon, for example, may provide valid scientific 'knowledge' about whether a certain night was dark” but "evidence that the moon was full on a certain night will not assist the trier of fact in determining whether an individual was unusually likely to have behaved irrationally on that night. Rule 702's 'helpfulness' standard requires a valid scientific connection to the pertinent inquiry as a precondition to admissibility.”).
.Whether or not the district court "conflated the questions of the admissibility of expert testimony and the weight appropriately to be accorded such testimony by a fact finder,” as the majority asserts, Maj. Op. at 141, (and I do not so con- ■ cede) we can and should, nonetheless, affirm the court’s decision for the reasons I have given. See Haddon v. Walters, 43 F.3d 1488, 1491 (“[W]e may affirm on different grounds the judgment of a lower court if it is correct as a matter of law.") (internal quotation and citation omitted).