Distinguishing Between Expert Reliability (Admissibility) And Credibility (Weight Of The Evidence)

Expert economist testimony on damages, while subject to well-founded challenge, was nonetheless reliable and therefore admissible; also the trial court was not required to hold a Daubert hearing before admitting the expert testimony and could rely on the extensive record and briefing, in In re Scrap Metal Antitrust Litigation, 527 F.3d 517 (6th Cir. 2008)

An antitrust decision from the Sixth Circuit highlighted the distinction between a challenge to the reliability of expert testimony, which concerns the admissibility of the expert opinion, and the credibility of the expert testimony, which goes to the weight given the testimony.

In the case, the plaintiffs consisted of a class of industrial scrap-generating companies in Northeastern Ohio who filed a civil antitrust action against Columbia Iron and Metal Company and related defendants, claiming they “engaged in a variety of unlawful acts including allocating scrap metal generators among dealers, agreeing not to compete with one another, submitting rigged bids, setting prices for the purchase of unprocessed scrap metal, and imposing financial penalties on co-conspirators for disobeying allocation agreements.” Scrap Metal, 527 F.3d at 523. All but three defendants settled prior to trial. The defendants moved to exclude the expert economist testimony of Dr. Leitzinger concerning his damages analysis. The trial court denied the motion after reviewing the extensive briefing and concluding that the challenges went to the weight but not admissibility of the evidence:

“Despite [Columbia’s] many well-supported attacks on the underlying data employed and assumptions made by Dr. Leitzinger in reaching his assumed damage calculation, the Court finds that those attacks are best reserved for cross-examination and do not, in this case, rise to the level warranting exclusion under Daubert. [Notwithstanding] “substantial room for debate” [concerning the expert’s data set and certain assumptions,] Dr. Leitzinger has provided reasoned explanations for the assumptions that he made and has, at least at [this] stage, presented viable arguments to support his data set choices. Whether those explanations will withstand rigorous crossexamination, or challenges based on alternative assumptions or data choices, is not the issue now before the Court. The Court concludes that Dr. Leitzinger’s opinions satisfy the Daubert standard and that [Columbia’s] criticisms of those opinions simply are appropriate fodder for cross-examination.”
Scrap Metal, 527 F.3d at 527.


The expert testified in essence that the defendants would have paid “16.4 percent more for unprocessed ferrous scrap metal in the absence of an antitrust conspiracy” and estimated damages to be nearly $21 million based on the total purchases of ferrous scrap metal. The jury ruled for the plaintiffs and the court awarded damages exceeding $23 million. On appeal, the defendants challenged the admission of the expert damages testimony at trial.

The Sixth Circuit affirmed the admission of the expert damage testimony. In doing so, the circuit distinguished between the reliability of an expert opinion and credibility of the opinion:

“Columbia’s argument is unpersuasive because it fundamentally confuses the credibility and accuracy of Leitzinger’s opinion with its reliability. Contrary to Columbia’s assertions, a determination that proffered expert testimony is reliable does not indicate, in any way, the correctness or truthfulness of such an opinion.… The task for the district court in deciding whether an expert’s opinion is reliable is not to determine whether it is correct, but rather to determine whether it rests upon a reliable foundation, as opposed to, say, unsupported speculation…. In sum, the jury was free to give Leitzinger’s opinion little or no weight, and to credit instead Defendants’ attacks on his decision to back out the adjustments. We cannot say that the district court abused its discretion in admitting Leitzinger’s testimony when the record shows that he performed his analysis according to a reliable method (the ‘during and after’ method) and reliably applied that method to the facts of this case. Moreover, Leitzinger’s calculations were tested on cross-examination and subjected to further scrutiny and criticism by Defendants’ own expert. The question of whether Leitzinger’s opinion is accurate in light of his use of the SPB data goes to the weight of the evidence, not to its admissibility, and the district court appropriately passed the torch to the jury to make this determination.”
Scrap Metal, 527 F.3d at 529-30, 531.


The circuit also held that the trial court was not required to hold a Daubert hearing before admitting the expert testimony. The circuit noted that the trial court had “spent a substantial amount of time and effort reviewing the parties' voluminous filings relative to the admissibility – or inadmissibility – of [the expert's] testimony pursuant to the applicable standards set forth in Daubert.” Scrap Metal, 527 F.3d at 527, 532 (“we note that the district court did not abuse its discretion by failing to hold a Daubert hearing, because the record on the expert testimony was extensive, and the Daubert issue was fully briefed by the parties”).

For other cases addressing the discretion in the court on this issue, see Full Daubert Hearing Is Not Always Required To Admit Expert Testimony Part I; Part II; or Part III.

Federal Rules of Evidence
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