CRA Competition experts were retained on behalf of Google to provide expert economic analysis in US private class action litigation challenging Google’s digital advertising practices. The mandate was to address class certification issues for the proposed US Advertiser Class and US Publisher subclasses, and to evaluate the economic evidence underlying plaintiffs’ theories of harm.
In December 2025, the US Court denied class certification for the proposed US Advertiser Class and the proposed US AdSense Publisher subclass. Plaintiffs had alleged that Google violated the Sherman Act by charging supracompetitive prices and manipulating auction outcomes across its adtech stack, which included AdX, AdSense, and Google Ads.
Plaintiffs’ theories assumed that Google’s alleged conduct produced uniform, class-wide harm across diverse advertisers and publishers, asserting that manipulation on one platform necessarily affected outcomes on others and that injury could be shown using aggregated data.
CRA’s US team analyzed hundreds of terabytes of data and demonstrated that the digital advertising ecosystem produces highly individualized outcomes, with substantial variation across proposed US class members and auction events. The economic analysis showed that plaintiffs’ assumptions regarding cross platform effects were inconsistent with the economic and technical realities of Google’s implementation of its ad tech products.
CRA’s US team further established that the named plaintiffs were not economically representative of the broader US classes they sought to represent. CRA experts Dr. Laila Haider and Dr. Gregory Leonard submitted expert reports, provided deposition testimony, and filed declarations that the US Court cited extensively in its decision.
The US Court ultimately concluded that plaintiffs failed to meet the Rule 23 requirements for class certification, and it denied certification for the US Advertiser Class and one of the two US Publisher subclasses. This decision reduced Google’s potential damages exposure by approximately half.
The CRA team was led by Dr. Haider and Dr. Leonard and supported by economists across several US offices, including Noah Schwartz, Dr. Yi Cheng, Dr. Bac Tran, Dr. Mengxi Wu, Dr. Javier Brugués, Dr. Alfia Karimova, Dr. Evgeniya Victorova, Dr. Hexuan Zhang and others.
