The revelation that Volkswagen had employed an illegal “defeat device” to comply with regulation, but fundamentally side-step some emission controls during realworld driving, has thrust the issue of regulatory non-compliance into the spotlight. A growing base of evidence has indicated that one of the underlying reasons for the observed emissions discrepancies, and subsequently the Volkswagen Scandal, is shortcomings in regulatory compliance protocols. This has raised questions about the efficacy of the United States and European Union regulatory frameworks for vehicle emissions, which both incorporated elements of performance based regulation, albeit with nuanced applications differing in terms of their enforcement and monitoring activities. Scholars have often argued that performance-based regulation can only be as good as a regulator’s ability to monitor outcomes, however, this research argues
that that performance-based regulation can only be as good as a regulator’s ability to enforce outcomes. Building on from the scholarly evidence that links regulatory design to regulatory outcomes, this research will ask: to what extent can the different responses of the United States and the European Union to the Volkswagen Scandal be explained by their different applications of performance-based regulation? Using a triangulation of evidence from government documents –including documents from the recently established European Parliament Committee on Emissions Measurements in the Automotive Sector-, non-government documents, and semi-structured interviews, this research uses a process tracing approach to explain that the different responses of the United States and the European Union to the Volkswagen Scandal can be explained as a result of their application of performance based regulation: specifically enforcement capabilities.