Supreme Court Requires Proof at Certification Stage that Damages Can Be Measured on Class-Wide Basis

by Ballard Spahr LLP

In a 5-4 decision, the Supreme Court decided earlier this week that putative class plaintiffs could not bring a class action antitrust lawsuit unless they could show that their damages could be measured on a class-wide basis. Justice Scalia authored the decision for the majority, while Justices Ginsburg and Breyer issued a joint dissent.

In Comcast Corp. v. Behrend, the plaintiffs alleged that Comcast violated federal antitrust laws by taking steps to become the only cable television provider in the Philadelphia area. The plaintiffs alleged that Comcast engaged in a strategy of clustering its operations in the Philadelphia region, and that Comcast used its allegedly dominant market position to stifle competition. The plaintiffs sought to certify a class, which required them to show that the class members were all harmed by the same alleged anticompetitive conduct, and the harm from this alleged conduct could be measured the same way for all class members.

The plaintiffs proposed four theories for how Comcast’s activities had reduced competition and elevated prices, but the district court found only one of these theories capable of class-wide proof, rejecting the other three. The theory that survived the district court's scrutiny was that Comcast used its market position to deter "overbuilders" from opening competing cable networks in its region.

To show that damages could be measured on a class-wide basis, plaintiffs produced a regression model comparing actual cable prices in the Philadelphia area with hypothetical prices that would have prevailed but for Comcast’s allegedly anticompetitive activities. But the plaintiffs’ damages model assumed the validity of all four theories of antitrust impact, even though the district court had rejected three of the four. Despite these flaws in the model, the court held that the plaintiffs had met their burden of showing that damages were capable of measurement on a class-wide basis.

Comcast appealed the class-certification decision to the Third Circuit. It argued that the faulty damages model meant the plaintiffs had failed to establish that all class members’ damages could be measured in the same way. The Third Circuit refused to consider the argument on the grounds that it was premature, holding that an attack on damages methodology was appropriate only at the merits stage of the case.

The Supreme Court reversed. It held that a party seeking to certify a class must be prepared to meet all of the certification prerequisites—including that damages be measurable on a class-wide basis—at the class-certification stage. The Court further held that the Third Circuit erred when it refused to entertain Comcast’s argument against use of the damages model proffered by the plaintiffs. Despite protests from the plaintiffs’ bar that requiring a merits-like analysis at such an early stage would make it more difficult to file antitrust class actions, the Court explained that a class determination demands rigorous analysis and "generally involves considerations that are enmeshed in the factual and legal issues comprising the plaintiff’s cause of action."

The Court held that the plaintiffs had not shown that certification was appropriate because the proffered damages methodology "failed to measure damages resulting from the particular antitrust injury on which petitioners' liability in this action is premised." In other words, the model did not measure impact caused solely by the remaining theory of Comcast's alleged deterrence of overbuilder competition.

Interestingly, when the Court granted certiorari, it formulated the question it wanted the parties to address, which was "[w]hether a district court may certify a class action without resolving whether the plaintiff class has introduced admissible evidence, including expert testimony, to show that the case is susceptible to awarding damages on a class-wide basis." Although the parties addressed whether the opinions of plaintiffs' damages expert could pass muster under Daubert v. Merrell Dow Pharmaceuticals, the Court only briefly touched upon Daubert in a footnote, without ruling on the issue.

This decision comes on the heels of the Court’s 2011 decision in Wal-Mart Stores, Inc. v. Dukes. In both cases, the Court stressed that when class certification depends on predominance of commonalities across a potential class, all important facets of the claim must be capable of common proof.

Ballard Spahr’s Antitrust Group has substantial experience defending class actions involving antitrust allegations. For more information on this decision or antitrust issues in general, please contact Leslie E. John at 215.864.8212 or, or Jason A. Leckerman at 215.864.8266 or

DISCLAIMER: Because of the generality of this update, the information provided herein may not be applicable in all situations and should not be acted upon without specific legal advice based on particular situations.

© Ballard Spahr LLP | Attorney Advertising

Written by:

Ballard Spahr LLP

Ballard Spahr LLP on:

Readers' Choice 2017
Reporters on Deadline

"My best business intelligence, in one easy email…"

Your first step to building a free, personalized, morning email brief covering pertinent authors and topics on JD Supra:
Sign up using*

Already signed up? Log in here

*By using the service, you signify your acceptance of JD Supra's Privacy Policy.
Custom Email Digest
Privacy Policy (Updated: October 8, 2015):

JD Supra provides users with access to its legal industry publishing services (the "Service") through its website (the "Website") as well as through other sources. Our policies with regard to data collection and use of personal information of users of the Service, regardless of the manner in which users access the Service, and visitors to the Website are set forth in this statement ("Policy"). By using the Service, you signify your acceptance of this Policy.

Information Collection and Use by JD Supra

JD Supra collects users' names, companies, titles, e-mail address and industry. JD Supra also tracks the pages that users visit, logs IP addresses and aggregates non-personally identifiable user data and browser type. This data is gathered using cookies and other technologies.

The information and data collected is used to authenticate users and to send notifications relating to the Service, including email alerts to which users have subscribed; to manage the Service and Website, to improve the Service and to customize the user's experience. This information is also provided to the authors of the content to give them insight into their readership and help them to improve their content, so that it is most useful for our users.

JD Supra does not sell, rent or otherwise provide your details to third parties, other than to the authors of the content on JD Supra.

If you prefer not to enable cookies, you may change your browser settings to disable cookies; however, please note that rejecting cookies while visiting the Website may result in certain parts of the Website not operating correctly or as efficiently as if cookies were allowed.

Email Choice/Opt-out

Users who opt in to receive emails may choose to no longer receive e-mail updates and newsletters by selecting the "opt-out of future email" option in the email they receive from JD Supra or in their JD Supra account management screen.


JD Supra takes reasonable precautions to insure that user information is kept private. We restrict access to user information to those individuals who reasonably need access to perform their job functions, such as our third party email service, customer service personnel and technical staff. However, please note that no method of transmitting or storing data is completely secure and we cannot guarantee the security of user information. Unauthorized entry or use, hardware or software failure, and other factors may compromise the security of user information at any time.

If you have reason to believe that your interaction with us is no longer secure, you must immediately notify us of the problem by contacting us at In the unlikely event that we believe that the security of your user information in our possession or control may have been compromised, we may seek to notify you of that development and, if so, will endeavor to do so as promptly as practicable under the circumstances.

Sharing and Disclosure of Information JD Supra Collects

Except as otherwise described in this privacy statement, JD Supra will not disclose personal information to any third party unless we believe that disclosure is necessary to: (1) comply with applicable laws; (2) respond to governmental inquiries or requests; (3) comply with valid legal process; (4) protect the rights, privacy, safety or property of JD Supra, users of the Service, Website visitors or the public; (5) permit us to pursue available remedies or limit the damages that we may sustain; and (6) enforce our Terms & Conditions of Use.

In the event there is a change in the corporate structure of JD Supra such as, but not limited to, merger, consolidation, sale, liquidation or transfer of substantial assets, JD Supra may, in its sole discretion, transfer, sell or assign information collected on and through the Service to one or more affiliated or unaffiliated third parties.

Links to Other Websites

This Website and the Service may contain links to other websites. The operator of such other websites may collect information about you, including through cookies or other technologies. If you are using the Service through the Website and link to another site, you will leave the Website and this Policy will not apply to your use of and activity on those other sites. We encourage you to read the legal notices posted on those sites, including their privacy policies. We shall have no responsibility or liability for your visitation to, and the data collection and use practices of, such other sites. This Policy applies solely to the information collected in connection with your use of this Website and does not apply to any practices conducted offline or in connection with any other websites.

Changes in Our Privacy Policy

We reserve the right to change this Policy at any time. Please refer to the date at the top of this page to determine when this Policy was last revised. Any changes to our privacy policy will become effective upon posting of the revised policy on the Website. By continuing to use the Service or Website following such changes, you will be deemed to have agreed to such changes. If you do not agree with the terms of this Policy, as it may be amended from time to time, in whole or part, please do not continue using the Service or the Website.

Contacting JD Supra

If you have any questions about this privacy statement, the practices of this site, your dealings with this Web site, or if you would like to change any of the information you have provided to us, please contact us at:

- hide
*With LinkedIn, you don't need to create a separate login to manage your free JD Supra account, and we can make suggestions based on your needs and interests. We will not post anything on LinkedIn in your name. Or, sign up using your email address.