This book locates recent developments in teacher certification in North America within a broader, international policy context characterised as hegemonic neo-liberalism wherein economic rationalism has begun to trump professional judgement. We focus on teacher certification because it addresses fundamental questions about who will teach, what are the required minimum levels of competence, and who will make those decisions. Such questions are central to teaching, constituting a new battleground for education in North America. Two ideas—economic rationalism and professionalisation—have become pivotal to education policy. Economic rationalism finds its expression in a free market ideology. Professionalisation has two meanings: professionalizing the practice of teaching (constructing a professional knowledge base); and professionalizing the status of teaching (through links with universities and self-regulation). These ideas’ contestation varies by setting. In the USA, neo-liberalism has attacked professional knowledge, questioning its scientific veracity. Professionalisation advocates claim that the neo-liberalist aim is to undermine teaching as a profession. In Canada, neo-liberalist critics are heard but have limited impact on policy. Professionalisation has emphasised teachers’ pedagogical development and a valuing of the field’s input into teacher preparation. Neo-liberalist economic rationalism plays itself out overtly in the USA as deregulation; in Canada, it lies embedded within labor mobility agreements. In the USA, professionalisation highlights professionalism in practice; in Canada, the governance of teaching. This book explores how economic rationalism is using labor mobility agreements in Canada as a covert operation analogous to deregulation in the USA to assert its dominance in the battle to de-professionalize teaching in North America.