CAT favours Professor Stephan’s £2.7bn Amazon class action claim

The UK’s Competition Appeal Tribunal (“CAT”) found in favour of Professor Andreas Stephan’s claim in a carriage dispute relating to which of two partially overlapping claims against Amazon should proceed.

Professor Stephan’s claim alleges that Amazon engaged in a range of anticompetitive conducts to the detriment of c. 200,000 “third-party sellers” in the UK who use the Amazon marketplace to sell goods. A second claim, brought by BIRA (British Independent Retailer’s Association), a UK trade association, alleged some but not all of the same anticompetitive conducts.

The CAT’s decision followed hearings held in November 2024 and determined that Professor Stephan’s claim is “more suitable” to proceed to a certification hearing than the competing claim brought by BIRA.

Frontier Economics provided an expert report to support Professor Stephan’s claim. The CAT noted, “Altogether, we found that Dr. Houpis’ comprehensive report presented an impressively well-developed and thought through methodology.” The CAT found further reassurance in the supplementary expert report, provided by David Dorrell, Frontier’s Head of Data Science, which set out the technical feasibility of evaluating the impact of the algorithms of the kind that are central to this case.

Frontier regularly advises clients on competition issues, including parties to a number of collective proceedings before the CAT.