Measuring Trademark Dilution by Tarnishment

The law of trademark tarnishment—a type of trademark dilution—is in disarray. The basic definition is deceptively simple. Trademark tarnishment occurs when a junior mark harms the reputation of a substantially similar existing senior trademark by associating itself with something perverse or deviant. However, it turns out that Congress and the courts disagree over the prima facie evidence necessary to prove its existence. The problem is that federal law and related legal principles are simply ill-equipped to adequately analyze this unique market-driven doctrine. To make matters worse, legal scholars cannot even agree on whether trademark tarnishment can empirically exist in the marketplace. Part of the issue is that there has never been any real attempt to define the phrase “harm to reputation” in the trademark context. Drawing on marketing scholarship and social science methods, this Article provides the first workable framework that courts can use to hear and accurately analyze these cases. It relies on experimental survey methodology to empirically show that tarnishment can exist under certain conditions; the key is increasing the number of exposures to the harmful mark. The Article also introduces extant branding theory as a way to define harm to reputation in the marketplace. This interdisciplinary approach ultimately gives courts a mechanism by which to measure harm to reputation and the tangible impact of tarnishment. In the process, this theory provides litigants with an empirical-based strategy to prove their dilution claims and contributes to the doctrinal justification for trademark dilution laws