Refusal to license intellectual property rights (IPRs) are an ongoing topic within the enforcement of Article 102 TFEU (ex Article 82 EC). Nevertheless, so far an economic founded instrument to analyse these cases is missing. To close this gap, the Innovation Effects and Appropriability Test will be developed throughout this book. Innovation research has been showing that firms rely on more appropriation mechanisms than only IPRs. The availability of these alternative instruments depends on the involved technologies, the kind of innovation, the concerned industry and so on. Consequently, it is in the centre of the Innovation Effects and Appropriability Test to analyse whether the dominant firm could rely on other appropriation instruments to protect its innovation and to recoup its investments in R&D.