Market Definition and Market Power. As the district court stated on remand, like many other courts before it, the first step in a rule-of-reason analysis was to determine the relevant market. In terms of antitrust claims for anticompetitive RPM, plaintiffs had to plausibly define the proper relevant market under the rule of reason. According to Du Pont, relevant market was determined by considering all reasonably interchangeable alternatives based on price, use, and quality.205）The Fifth Circuit on remand affirmed the citation regarding market definition by the district court and cited again the same precedent more explicitly than the district court. In Apani, the Fifth Circuit had held that,“[w]here the plaintiff fails to define its proposed relevant market with reference to the rule of reasonable interchangeability and cross-elasticity of demand, or alleges a proposed relevant market that clearly does not encompass all interchangeable substitute products even when all factual inferences are granted in plaintiff’s favor, the relevant market is legally insufficient, and a motion to dismiss may be granted.”206） In its second amended complaint, PSKS alleged that the relevant product markets at issue in the case were the“retail market for Brighton’s women’s accessories”and the“wholesale sale of brand-name women’s accessories to independent retailers.”In response to the former claim that Brighton’s products had their own market, Xxxxxx opposed the market definition, arguing that countless brands were reasonably interchangeable in use with Brighton products. The district court associated PSKS’s market definition with a single brand market argument and stated the difficulty of insisting on such a single market as a relevant market in the light of previous cases including precedent from within the Circuit. In Domed Stadium, the Fifth Circuit held that absent exceptional market conditions, one brand in a market of competing brands could not constitute a relevant product market.207）Referring to Kodak,208）the court of appeals also held that, in rare circumstances, a single brand of a product could constitute a relevant market for antitrust purposes. According to Xxxxx, that possibility was limited to situations in which consumers were“locked in”to a specific brand by the nature of the product.209）The“locked in”situations could be caused by a structural barrier in the market, but no such structural barrier was found in terms of interchangeability of Brighton products with other competing manufacturers’...
