Defense cartel econometrician

Expert class library · Antitrust · Defense side

Takes apart the plaintiffs' overcharge model in price-fixing and benchmark-collusion cases by testing the benchmark period, the control variables and the single pooled overcharge, and offers the defense's own reading of prices and transaction data. Appears at class certification and at the merits, where courts also police the line between economic analysis of collusion and opinions about what the antitrust laws should allow.

What this expert is retained to answer

• Does the plaintiffs' benchmark period reflect competitive conditions, or does a demand shift or recession at its edge explain the price difference?
• Does the model control for costs, demand and capacity, and do its results survive a structural break test?
• Does a single pooled overcharge hide differences across products, regions or customers?
• Can the defense rely on offsetting price cuts or other benefits, or does price-fixing law make them irrelevant?
• Do actual transaction prices contradict the price effect the plaintiffs claim?
• Is the economist offering economic analysis, or an opinion on what conduct the law should punish?

Methods

• Re-estimation of the plaintiffs' overcharge regression
• Benchmark period and structural break testing
• Demand, cost and capacity control testing
• Alternative but-for price analysis
• Analysis of actual transaction prices
• Economics of collusion and coordination

How the testimony is attacked

• Offsets that the law does not recognize. Plaintiffs move to exclude defense opinions that customers received offsetting benefits. In the Delta/AirTran baggage fee litigation the court excluded four defense experts' opinions on base-fare reductions at class certification, holding that offsetting benefits cannot reduce price-fixing damages or defeat impact.
• Opinions about what the law should be. Plaintiffs object when a defense economist argues that sound antitrust policy should permit the conduct. At the merits stage of the same litigation the court excluded that opinion as telling the jury what result to reach, while admitting the economist's opinions that the fee was likely inevitable and had business justifications.
• Economic preconditions presented as the legal test. Plaintiffs attack testimony that collusion cannot exist without proof of specific conditions such as monitoring and punishment. The Delta/AirTran court excluded a defense economist's definition of collusion framed as preconditions to liability, but admitted his cheap talk analysis testing the plaintiffs' model.
• Critique without an alternative model. Plaintiffs argue a defense econometrician who only criticizes, and never runs his own regression, offers little to weigh. In In re Domestic Drywall the court found the defense expert credible but gave little weight to his local-market, longer-benchmark and capacity opinions, noting he ran no independent regression, and certified the class.
• A benchmark that spans a recession. Plaintiffs attack a defense benchmark period stretched to include unusual market conditions. The Drywall court found the defendants' proposed lengthy benchmark had many defects because it included the Great Recession.
• Attacks that mischaracterize the analysis. Defense economists often survive challenges that misread what they did. In the LIBOR litigation the court denied motions to exclude a defense economist's analysis of the banks' actual interbank borrowing rates, holding that the motions mischaracterized his report and were contradicted by the plaintiffs' own pleadings.

What the public record shows

A deliberately narrow CourtListener search, overcharge AND regression AND ("price-fixing" OR "price fixing" OR cartel) AND ("defendants' expert" OR "Defendants' expert" OR "defense expert") AND (Daubert OR "Rule 702") AND exclude, returned 9 opinions filed since 2015, as of October 3, 2026; broader searches return more. 4 rulings that show how courts handle this class of testimony:

Each case links to the free opinion text on CourtListener.

Under amended Rule 702

Since December 1, 2023, Rule 702 says expressly that the party offering an expert must show the court it is more likely than not that the testimony meets each requirement: that it rests on sufficient facts or data, uses reliable methods, and reflects a reliable application of those methods to the case. Questions about the basis of an opinion are no longer automatically matters of weight for the jury. For how the circuits have applied the amendment, see the Rule 702 tracker, which follows each court of appeals; for what that means for preparing or attacking this class of expert, see the guide on amended Rule 702.

Related classes

• Cartel-overcharge damages economist
• Defense class-certification antitrust economist
• Plaintiff common-impact economist
• Indirect-purchaser pass-through economist

Guides

• Common Impact and Pass-Through at Class Certification
• Amended Rule 702 After Nearly Three Years: What Courts Exclude

Simulating this class on a matter

Supreme Mind simulates a class of expert, never a named individual, on your fact pattern and returns the likely opinion, the ranked cross-examination weaknesses, the Rule 702 attack surface and what it means for settlement. Read how it works, or book a demo.

Last reviewed October 3, 2026. How this page is built: rulings are found by searching court opinions on CourtListener, and each one is read in the opinion before it is summarised here; outcomes are labelled by what the court did with the expert's testimony. No individual expert is named. This page summarises public decisions for orientation and is not legal advice; read the opinion before relying on any ruling.