What’s in a Price? History of Economic Ideologies vs. History of Economic Ideas. This paper suggests applying the approach of a historical epistemology to the field of economics. We observe that an assumedly fundamental opposition between the market and the state dominates popular images of the history of economic ideas. Two conflicting ideologies are roughly assigned to the two opposing sides in the Cold War. To this historical narrative the paper opposes a different view. The argument is that when taking the technical practices of economic knowledge production in the twentieth century into view, similarities abound across ideological ruptures. The chief characteristic change in the recent history of economics was a radical turn towards quantification, measurement, and mathematical modelling. A historical epistemology of economics could show how deeply both, admirers of the state and of the market, share a history. The paper concludes that to-date critique of political economy should also take into consideration a critical perspective towards the unfolding of this measurement revolution in the social sciences.