1 This is an Author's Accepted Manuscript of an article published in The European Journal of the History of Economic Thought, 2017, doi 10.1080/09672567.2017.1285121, available online at: http://www.tandfonline.com/eprint/aZzU6Q9X87nXfWHRKtEt/full. Book review: Paul Erickson: The World the Game Theorists Made. The University of Chicago Press, Chicago, 2015. 390 pp. ISBN 978-0-226-09703-9 (cloth), 978-0-226-09717-6 (paper), 978-0-226- 09720-6 (e-book), DOI: 10.7208/Chicago/9780226097206.001.0001. 1 The World the Game Theorists Made is a carefully-researched history of game theory, and an aŵďitious projeĐt: EriĐksoŶ’s aim is to provide a unifying narrative of more than 50 years of game theorLJ folloǁiŶg the puďliĐatioŶ of ǀoŶ NeuŵaŶŶ & MorgeŶsterŶ’s ;1ϵ44Ϳ Theory of Games and Economic Behavior. The second chapter (after an introductory overview) contains the genesis and a synopsis of this seminal work, and the following five chapters the subsequent development of game theory, its main players, and its embedding not only in the history of science but also in the cultural environment moulded mainly by Cold War-America. As such, it is the most extensive history of game theory and game theoretical thinking available to date, and goes beyond the often found and mutually disconnected accounts of the long history of probability and games of chance, of the role game theory played in the Cold War era, or of how evolutionary theory entered the stage in the development of a theory of social interaction without rationality. EriĐksoŶ’s ďook has all of this, aŶd gives credible explanations of the links between the different fields and concerns game theorists were drawn to deal with. The unifying narrative Erickson offers is that gaŵe theorLJ’s enduring success is to be explained through the fact that it provides (quite heterogeneous) mathematical tools flexible enough to figure in a wide range of social scientific themes and models and which, although quite heterogeneous, nevertheless kŶit theŵ together iŶto a ĐoŵŵoŶ ĐoŶǀersatioŶ ;p. 14). Moreover, whereas the formal core was essentially preserved, its semantics was subject to various shifts following the focus of the theory. Perhaps the most prominent example of such a reinterpretation is the evolutionary perspective on equilibrium selection. This narrative is able to explain why the history of game theory is full of promises and setbacks from its beginning. For example, Erickson observes that ǀoŶ NeuŵaŶŶ aŶd MorgeŶsterŶ’s opus did Ŷot haǀe an obvious audience: too applied for mathematicians, and too mathematical for economists, it nevertheless contained the appealing promise that a unifying explanation of the social sciences can eventually be found in the mathematics of the strategic interaction of rational agents. This promise was enthusiastically adopted in evolving Cold War-America and its numerous military-sponsored research programmes. What is more, according to Erickson, the development and success story of game theory was partly caused by the political will of early Cold War-America, where a great part of the basic research in game theory was demanded and paid for by military and semi-governmentally funded organisations such as the RAND corporation – whereas classical research in academic institutions was sparse, mainly because the gaŵe theorists’ ǁork did not fit well in the academic division of labour. The very core of 1 Reviewed by: Philippe van Basshuysen, London School of Economics and Political Science, London, UK.