After Adam Smith's statement of market virtues, the process of gestation of economic policy as a rational set of rules for public agenda has been rather slow. Until not so long ago, economic policy as a discipline was often confined to prescribing practical rules intended to explain technical procedures of government intervention. Economic policy– as a coherent and to some extent autonomous discipline–only emerged in the late 1950s in Scandinavia, the Netherlands and Italy, when solid foundations indicating not only microeconomic but also macroeconomic market failures and a theory about the conditions for policy effectiveness and design were consistently developed. This paper intends to explain the reasons for the emergence of the discipline, the circumstances that favoured its diffusion, the reasons for its apparent setback and some factors that could facilitate its diffusion in the next years