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Find a Antitrust Expert →Overview
An antitrust expert, usually an industrial organization economist, answers two questions: did this conduct harm competition, and if so, by how much? The first turns on the market, the defendant's power in it, and what would have happened otherwise. The second turns on a damages model that isolates the harm from the conduct and nothing else. This page covers competition economics. A forensic accountant may audit the data, and an industry expert may explain how the business works.
The core statutes are short and old, so most of the law is about economics. The Sherman Act of 1890 outlaws every contract, combination or conspiracy in restraint of trade, along with monopolization and attempted monopolization, and the Supreme Court has long read it to reach only unreasonable restraints 1. Section 7 of the Clayton Act prohibits acquisitions whose effect may be substantially to lessen competition or to tend to create a monopoly 1. A private plaintiff who is injured may recover threefold the damages sustained, plus the cost of suit and a reasonable attorney's fee 2. That multiplier explains why the damages model draws such close attention.
The standard of review decides how much economics the case needs. Plain agreements among competitors to fix prices, divide markets or rig bids are per se violations, for which the FTC says no defense or justification is allowed 1. Those can also be crimes. The FTC reports criminal penalties of up to $100 million for a corporation, $1 million for an individual, and up to 10 years in prison 1. In such a case the economist usually addresses whether the evidence fits collusion, and what the overcharge was.
Most other restraints fall under the rule of reason. In Ohio v. American Express, the Court described a three-step, burden-shifting framework, in which the plaintiff first proves a substantial anticompetitive effect that harms consumers in the relevant market 3. In NCAA v. Alston, the Court said this analysis generally requires a fact-specific assessment of market power and market structure, and that an abbreviated quick look fits only some circumstances 4.
Most cases rise or fall here. The expert decides what products and places compete. The agencies' 2023 Merger Guidelines describe the hypothetical monopolist test, which asks whether a sole seller in a proposed market could profitably worsen terms significantly, for example by raising price 5. Practical indicia also matter, including those from Brown Shoe 5.
Platforms changed this work. In American Express, the Court held that both sides of the credit card market had to be considered, and that evidence of a price increase on one side of a two-sided transaction platform cannot, by itself, show an anticompetitive exercise of market power 3. Any expert in a platform case now has to address both sides, or explain why the platform is not of that type.
The opinion may rest on either kind of proof the Court described: direct evidence of harm, or indirect evidence, meaning proof of market power plus some evidence that the restraint harms competition 3.
The Guidelines set structural markers. Markets with a Herfindahl-Hirschman Index above 1,800 are highly concentrated, a change of more than 100 points is a significant increase, and a merger meeting both is presumed to substantially lessen competition 5. The FTC announced in February 2025 that the 2023 Guidelines are in effect and will serve as the framework for its merger review 6. They describe how the agencies analyze mergers. A court decides the case under Section 7, so the expert should tie the analysis to the statute as well.
The damages model is usually a before-and-after comparison, a yardstick market, or a regression of prices on the alleged conduct and on other factors that move prices. Two legal limits shape that work:
No license applies to this work. Look for a doctorate in economics with a focus on industrial organization, published or academic work, or senior experience at the DOJ Antitrust Division or the FTC. Ask whether the expert has been excluded in prior cases and why, and whether the model has been tested on the actual transaction data. Separate the roles. An economist addresses market power and damages. An industry expert addresses how the trade operates, and a forensic accountant can address the integrity of the data.
Under the 2023 Merger Guidelines, a market with a Herfindahl-Hirschman Index above 1,800 is highly concentrated, and a merger that raises the index by more than 100 points in such a market is presumed to substantially lessen competition.
Case Types
Price fixing, bid rigging, and market allocation conspiracies
Monopolization and attempted monopolization claims
Exclusive dealing, tying, and loyalty discount disputes
Merger challenges under Section 7 of the Clayton Act
Two-sided platform and app marketplace restraints
Class certification disputes over common impact and damages models
Overcharge and lost profits damages in private treble damages suits
Labor market restraints, including wage-fixing and no-poach agreements
Qualifications
Related Specialties
FAQ
Look for a doctorate in economics with a focus on industrial organization, plus published work or senior experience at the DOJ Antitrust Division or FTC. The expert should be able to define a market, build a damages model on actual transaction data, and show it fits the liability theory. Ask about prior exclusions.
Per se violations are plain agreements among competitors to fix prices, divide markets, or rig bids, and the FTC says no defense or justification is allowed. Most other restraints fall under the rule of reason, which the Supreme Court has said generally requires a fact-specific assessment of market power and market structure. The first asks whether the agreement existed. The second asks what it actually did to competition.
A common tool is the hypothetical monopolist test, described in the 2023 Merger Guidelines, which asks whether a sole seller in a proposed market could profitably worsen terms significantly, for example by raising price. Experts also use practical indicia of what buyers treat as substitutes. In platform cases, both sides of a two-sided transaction platform may need to be considered.
Under federal law, Illinois Brick generally bars an indirect purchaser from using a pass-on theory offensively. State law may differ, so the available claims depend on where and how the case is brought. An economist can then address how much of an overcharge passed through the chain where that question is permitted.
A common failure is a model that does not match the theory of liability. In Comcast v. Behrend, a model assumed four theories of antitrust impact when only one survived, and the Court held it had to measure only damages attributable to that theory. Models can also fail by leaving out other factors that move prices.
In general, antitrust expert fees are determined by the expert themselves, based on a variety of criteria. Among those criteria are academic standing, agency experience, forensic experience, the volume of data, and publications. Vident does have some influence over expert fees by comparing experts within a specialty, but ultimately it is a personal decision by the expert.
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