John L. Campbell and Ove K. Pedersen The National Origins of Policy Ideas: Knowledge Regimes in the United States, France, Germany, and Denmark, Princeton University Press, New Jersey, 2014; 401 pp: 978069116116-7 (pbk) $29.95 Within the closely related fields of international relations (IR) and international political economy (IPE), a hallmark of the last two decades has been the rise to prominence of constructivism as a key theoretical tradition. This has established itself more strongly in IR, where constructivism as a research programme is now taken to be one of the three mainstream traditions, along with realism and liberalism. Indeed, a consequence of this has been more recent attempts to re-emphasise the critical-theoretical foundations of constructivism, more in line with the classic philosophy of the social science approach of (for example) Berger and Luckmann than the widespread dilution that has occurred via debates with realists and liberals. In IPE, the rise of constructivism came later, and is also more weakly established as a research programme. This has meant that thorough, philosophically reflective, constructivist IPE accounts are virtually non-existent. Instead, we have had a number of well-known and well-written studies which nevertheless retreat significantly from the classic premises of constructivism to a considerably narrower focus on the importance of ideas in and of themselves, i.e. independent of other factors and processes. This has led to a significant bias in constructivist IPE towards an account of policy paradigms in national and international arenas, rather than the socially constructed and artificial nature of social and political life per se (for example, see Blyth 2013; Broome & Seabrooke 2014; Chwieroth 2010). As such, The National Origins of Policy Ideas is to be welcomed, for it provides a far more comprehensive approach than is usually the case, and in this sense it is closer in spirit to economic sociology and organisation studies than IPE. Campbell and Pedersen thus offer a much needed challenge to literatures in IPE and also in comparative political economy, and they point out early in the book that 'those who have shown that ideas are important have paid remarkably little attention to how these ideas are produced and disseminated in the first place' (p. 2; original emphases). As such, they focus 'on how policy research organizations like think tanks, government research units, political party foundations, and others that produce and disseminate policy ideas are organized, operate, and have changed during the past 30 years or so' (p. 3). Hence the term 'knowledge regime' rather than 'policy paradigm', for a study of the latter presupposes a critical understanding of the former. Campbell and Pedersen use this approach to achieve two main, more concrete goals. First, to provide an in-depth account of the evolution of knowledge regimes in four countries--the USA, France, Germany and Denmark--in lengthy and multifaceted chapters. Second, to reflect on these case studies in order to comment in two further chapters, on the limits to convergence in the contemporary, globalising period due to the nationally specific nature of the knowledge regimes, and on the degrees to which knowledge regimes are influential in different societies. On the first goal, my main interest was in the chapter on Germany. Many accounts of change in the German political economy have either viewed ideas/knowledge as mere instruments of broader strategic interactions between political actors or in narrow, policy-specific terms--both of which miss the bigger picture. It is thus often difficult to find analyses that combine detailed discussion of knowledge regimes with a political economy approach. Here, Campbell and Pedersen fall short of a fully satisfactory analysis (see below for more), but this is not for want of trying, and ultimately their thick descriptions of different modes of knowledge production and dissemination--for instance, party foundations and advocacy organisations--take them well beyond much of the literatures we have to date on the German knowledge regime. …