Policy consulting, as pointed out in the Introduction to this book, is an important but under-researched topic in policy studies. Policy consultancy has been a problematic blind spot for scholars, politicians and other commentators who are concerned with the substantive and procedural quality of the policies that shape our societies, and it is a far more important and sizeable component of the work that happens within government than the literature currently acknowledges. However, many questions about the roles and activities of policy consultants remain shrouded in mystery. Many of these questions are comparative in nature but require nuanced analysis. That is, the use and role of policy consultancy needs to be understood in terms of the political-administrative culture and structures of a given national polity, but the use of policy consultants is unevenly distributed across types of policy organizations and policy sectors.