Ninth Circuit Rejects Challenges to Conjoint Analysis in Consumer Class Action

In recent years, conjoint analysis has proliferated as a methodology for calculating class-wide damages in consumer class actions. While conjoint analysis first emerged as a marketing tool for measuring consumers’ relative preferences for various product attributes, many plaintiffs (and their experts) have attempted to employ conjoint analysis as a tool for measuring the “price premium” attributable to a labeling statement or the effect that the disclosure of a product defect would have had on the product’s price. Defendants, in turn, have taken the position that conjoint analysis is only capable of measuring consumer preferences, cannot account for the array of competitive and supply-side factors that affect the price of a product, and that it is therefore incapable of measuring the price effect attributable to a labeling statement or a disclosure. Consistent with that position, defendants in consumer class actions frequently argue not only that conjoint analysis is unsuited to measuring class-wide damages consistent with Comcast Corp. v. Behrend, 569 U.S. 27 (2013), but also that it is inadmissible under Federal Rule of Evidence 702 and Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). But a recent Ninth Circuit decision, MacDougall v. American Honda Motor Co., --- F. App’x ---- (9th Cir. 2021) may threaten defendants’ ability to challenge conjoint analysis on Daubert grounds.

In MacDougall, the plaintiffs brought a consumer class action against Honda premised on Honda’s alleged failure to disclose the presence of a transmission defect in its vehicles. The plaintiffs attempted to quantify the damages attributable to this omission through a conjoint analysis, which purported to “measure the difference in economic value—and thus the damages owed—between Defendants’ vehicles with and without the alleged transmission defect giving rise to this action.” MacDougall v. Am. Honda Motor Co., No. 17-1079, 2020 WL 5583534, at *4 (C.D. Cal. Sept. 11, 2020). Honda argued that this conjoint analysis was flawed and inadmissible, both “because it only accounts for demand-side and not supply-side considerations” and “because it utilizes an invalid design that obtains mostly irrational results.” Id. at *5. The district court agreed with Honda, excluded the expert’s conjoint analysis, and entered summary judgment in Honda’s favor based on the plaintiffs’ failure to offer admissible evidence of class-wide damages. In so holding, the court concluded that the expert’s conjoint analysis “calculates an inflated measure of damages because it does not adequately account for supply-side considerations” and only measures a consumer’s willingness to pay for certain product features—not the market price that the product would command in the absence of the purported defect. Id. “[W]ithout the integration of accurate supply-side considerations,” the district court explained, “a choice-based conjoint analysis transforms into a formula missing half of the equation.” Id. And separate and apart from this central economic defect, the district court found that other errors in the expert’s methodology—including his failure to conduct a pretest survey and the limited number of product attributes tested in the conjoint survey—rendered his conjoint analysis unreliable and inadmissible. See id. at *7-9.

The Ninth Circuit reversed. Beginning from the premise that expert testimony is admissible so long as it is “relevant” and “conducted according to accepted principles,” the Ninth Circuit found that the admissibility of expert testimony was a “case-specific inquiry” and therefore rejected Honda’s argument that “conjoint analysis categorically fails as a matter of economic damages.” Slip Op. at 2-3. The Ninth Circuit then concluded that Honda’s methodological challenges based on “the absence of market considerations, specific attribute selection, and the use of averages to evaluate the survey data go to the weight given the survey, not its admissibility.” Id. at 3 (citations and internal quotation marks omitted). And while the Ninth Circuit acknowledged that the district court relied on numerous decisions that had rejected the use of conjoint analysis in consumer class actions, it held that these decisions did not concern the “admissibility of conjoint analysis under Rule 702 or Daubert” but instead its “substantive probity in the context of either class-wide damages under Comcast . . . or substantive state law.” Id. at 2.

In distinguishing between the question of whether conjoint analysis is admissible under Daubert and whether it is capable of measuring damages on a class-wide basis consistent with Comcast, the Ninth Circuit preserved an opening for defendants to challenge the use of conjoint analysis to measure class-wide damages at the class certification stage. Nonetheless, MacDougall undoubtedly weakens defendants’ ability to challenge the admissibility of conjoint analysis on methodological grounds, and it is possible that some district courts may read the Ninth Circuit’s opinion to stand for the broad proposition that juries, rather than judges, should decide whether conjoint analysis can properly measure economic damages.

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© 2026 Jenner & Block LLP. Attorney Advertising. Jenner & Block LLP is an Illinois Limited Liability Partnership including professional corporations. This publication, presentation, or event is not intended to provide legal advice but to provide information on legal matters and/or firm news of interest to our clients and colleagues. Readers or attendees should seek specific legal advice before taking any action with respect to matters mentioned in this publication or at this event. The attorney responsible for this communication is Brent E. Kidwell, Jenner & Block LLP, 353 N. Clark Street, Chicago, IL 60654-3456. Prior results do not guarantee a similar outcome. Jenner & Block London LLP, an affiliate of Jenner & Block LLP, is a limited liability partnership established under the laws of the State of Delaware, USA and is authorised and regulated by the Solicitors Regulation Authority with SRA number 615729. Information regarding the data we collect and the rights you have over your data can be found in our Privacy Notice. For further inquiries, please contact dataprotection@jenner.com.

Ninth Circuit Rejects Challenges to Conjoint Analysis in Consumer Class Action

In recent years, conjoint analysis has proliferated as a methodology for calculating class-wide damages in consumer class actions. While conjoint analysis first emerged as a marketing tool for measuring consumers’ relative preferences for various product attributes, many plaintiffs (and their experts) have attempted to employ conjoint analysis as a tool for measuring the “price premium” attributable to a labeling statement or the effect that the disclosure of a product defect would have had on the product’s price. Defendants, in turn, have taken the position that conjoint analysis is only capable of measuring consumer preferences, cannot account for the array of competitive and supply-side factors that affect the price of a product, and that it is therefore incapable of measuring the price effect attributable to a labeling statement or a disclosure. Consistent with that position, defendants in consumer class actions frequently argue not only that conjoint analysis is unsuited to measuring class-wide damages consistent with Comcast Corp. v. Behrend, 569 U.S. 27 (2013), but also that it is inadmissible under Federal Rule of Evidence 702 and Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). But a recent Ninth Circuit decision, MacDougall v. American Honda Motor Co., --- F. App’x ---- (9th Cir. 2021) may threaten defendants’ ability to challenge conjoint analysis on Daubert grounds.

In MacDougall, the plaintiffs brought a consumer class action against Honda premised on Honda’s alleged failure to disclose the presence of a transmission defect in its vehicles. The plaintiffs attempted to quantify the damages attributable to this omission through a conjoint analysis, which purported to “measure the difference in economic value—and thus the damages owed—between Defendants’ vehicles with and without the alleged transmission defect giving rise to this action.” MacDougall v. Am. Honda Motor Co., No. 17-1079, 2020 WL 5583534, at *4 (C.D. Cal. Sept. 11, 2020). Honda argued that this conjoint analysis was flawed and inadmissible, both “because it only accounts for demand-side and not supply-side considerations” and “because it utilizes an invalid design that obtains mostly irrational results.” Id. at *5. The district court agreed with Honda, excluded the expert’s conjoint analysis, and entered summary judgment in Honda’s favor based on the plaintiffs’ failure to offer admissible evidence of class-wide damages. In so holding, the court concluded that the expert’s conjoint analysis “calculates an inflated measure of damages because it does not adequately account for supply-side considerations” and only measures a consumer’s willingness to pay for certain product features—not the market price that the product would command in the absence of the purported defect. Id. “[W]ithout the integration of accurate supply-side considerations,” the district court explained, “a choice-based conjoint analysis transforms into a formula missing half of the equation.” Id. And separate and apart from this central economic defect, the district court found that other errors in the expert’s methodology—including his failure to conduct a pretest survey and the limited number of product attributes tested in the conjoint survey—rendered his conjoint analysis unreliable and inadmissible. See id. at *7-9.

The Ninth Circuit reversed. Beginning from the premise that expert testimony is admissible so long as it is “relevant” and “conducted according to accepted principles,” the Ninth Circuit found that the admissibility of expert testimony was a “case-specific inquiry” and therefore rejected Honda’s argument that “conjoint analysis categorically fails as a matter of economic damages.” Slip Op. at 2-3. The Ninth Circuit then concluded that Honda’s methodological challenges based on “the absence of market considerations, specific attribute selection, and the use of averages to evaluate the survey data go to the weight given the survey, not its admissibility.” Id. at 3 (citations and internal quotation marks omitted). And while the Ninth Circuit acknowledged that the district court relied on numerous decisions that had rejected the use of conjoint analysis in consumer class actions, it held that these decisions did not concern the “admissibility of conjoint analysis under Rule 702 or Daubert” but instead its “substantive probity in the context of either class-wide damages under Comcast . . . or substantive state law.” Id. at 2.

In distinguishing between the question of whether conjoint analysis is admissible under Daubert and whether it is capable of measuring damages on a class-wide basis consistent with Comcast, the Ninth Circuit preserved an opening for defendants to challenge the use of conjoint analysis to measure class-wide damages at the class certification stage. Nonetheless, MacDougall undoubtedly weakens defendants’ ability to challenge the admissibility of conjoint analysis on methodological grounds, and it is possible that some district courts may read the Ninth Circuit’s opinion to stand for the broad proposition that juries, rather than judges, should decide whether conjoint analysis can properly measure economic damages.

Related Capabilities

© 2026 Jenner & Block LLP. Attorney Advertising. Jenner & Block LLP is an Illinois Limited Liability Partnership including professional corporations. This publication, presentation, or event is not intended to provide legal advice but to provide information on legal matters and/or firm news of interest to our clients and colleagues. Readers or attendees should seek specific legal advice before taking any action with respect to matters mentioned in this publication or at this event. The attorney responsible for this communication is Brent E. Kidwell, Jenner & Block LLP, 353 N. Clark Street, Chicago, IL 60654-3456. Prior results do not guarantee a similar outcome. Jenner & Block London LLP, an affiliate of Jenner & Block LLP, is a limited liability partnership established under the laws of the State of Delaware, USA and is authorised and regulated by the Solicitors Regulation Authority with SRA number 615729. Information regarding the data we collect and the rights you have over your data can be found in our Privacy Notice. For further inquiries, please contact dataprotection@jenner.com.

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