Introduction Intra-EU labour mobility has become a major structuring factor in certain occupational labour markets. Firms engage in transnational hiring and, in doing so, consciously strategize across sovereign sites and arenas of regulation in order to take advantage of lower cost structures and less strict regulatory environments. These practices are part of a pervasive dynamic of labour-cost competition that is integral to the growth of capitalist markets (Bernaciak, Introduction to this volume). They are embedded in the process of ‘creative destruction’ that inherently threatens social standards but, in mainstream economic thought, is also fundamental to the logic of capitalist accumulation. According to Schumpeter (1942), who coined the concept of creative destruction, capitalism progresses by destroying old social and production structures and replacing them with new, presumably more efficient ones. Schumpeter argues that, in the end, creative destruction will make society as a whole better off, although there will be winners and losers in the process. While the underlying necessity of creative destruction is rarely contested, the limits of what can be done to achieve it are. Defining these limits is the focus of the social dumping debate. When firms transgress certain normative boundaries as a way to make themselves more competitive, they often trigger accusations of social dumping. In Europe, such accusations usually refer to normative structures inherited from the post-war national industrial relations systems of Western Europe, which sought to ensure income stability for workers, humane treatment and due process in the workplace, as well as rights to workplace representation and collective action, reasonable notice prior to dismissals, and similar worker protections (Bernaciak, Introduction to this volume). However, business actors are constantly testing the boundaries of what is acceptable and what they can get away with (Streeck, 2009), and increasing numbers of employers reject the existing norms – if not in principle, then certainly in practice. Some companies play a double game in which they appear to support and conform to the traditional normative frameworks of industrial relations while in fact operating in ways that allow them to remain price competitive in unconstrained markets. For unions and society as a whole, the challenge is to enforce normative constraints upon such ‘unruly’ employers (Streeck, 2009, p. 75).