Simulation Models For The Quantification Of Cartel Damages

In the June issue of the German journal Wirtschaft und Wettbewerb (Economy and Competition), Managing Director Nicola Tosini and Felix Bönisch analyze the use of economic simulation models for quantifying cartel damages in litigation in the European Union, taking a German court’s (OLG Stuttgart’s) 20 November 2025 judgement in the European bathroom fittings cartel case as a starting point. In this landmark decision, the court developed a five-step framework for estimating cartel damages. While much of the prior public debate on the estimation framework has focused on the first three steps—establishing the existence and magnitude of a cartel-induced overcharge in the upstream market—this article concentrates on the fourth step, in which the court relied on an economic simulation model to assess how much of the overcharge was passed on to indirect purchasers in the downstream market.