Vertical interoperability in mobile ecosystems: Will the DMA deliver (what competition law could not)?

To address concerns about the competitive dynamics of digital markets, the promotion of interoperability has been often pointed out as a fundamental component of policy reform agendas. In the case of mobile ecosystems, the smooth and seamless availability of interoperability features is crucial as third-party devices and apps would be otherwise unable to effectively work and participate within the ecosystems. However, access to application programming interfaces (APIs) may be restricted due to privacy, security, or technical constraints. Further, an ecosystem orchestrator may misuse its rule-setting role to pursue anticompetitive goals by restricting or degrading interoperability for third-party services and devices. The paper aims at investigating whether and how effective interoperability could be achieved through the enforcement of competition rules or whether it would require regulatory interventions, such as those envisaged in the European Digital Markets Act (DMA). • Interoperability is essential in mobile ecosystems, which consist of interconnected tangible and digital elements. Without smooth interoperability, any device risks losing a significant part of its functionality. • As a leading example of regulatory trends in digital markets, the European Digital Markets Act (DMA) imposes obligations specifically on vertical interoperability in mobile ecosystems. • While EU competition law is, in principle, equipped to address anticompetitive vertical foreclosure strategies that restrict interoperability with third-party services, implementing effective remedial measures remains challenging. • Apple’s proposed technical solutions for DMA compliance raise important questions about the regulation’s ability to ensure effective enforcement.