This paper traces interpersonal utility comparisons and bargaining in the work of John Harsanyi from the 1950s to the mid-1960s. As his preoccupation with how theorists can obtain information about agents moved from an approach centered on empathetic understanding to the more distanced perspective associated with game theory, Harsanyi shifted emphasis from the social scientist’s lack of information vis-à-vis agents to agents’ lack of information about each other. In the process, he provided economists with an analytical framework they could use to study problems related to the distribution of information among agents while consolidating the perspective of a distant observer whose knowledge can replace that of real people.

In this paper, we show that Paul Samuelson (1915–2009), renowned as one of the main advocates of the mathematization of economics, has also contributed to the change of the place of visual representation in the discipline. In his early works (e.g. Foundations of Economic Analysis published in 1947), he rejected diagrammatic analysis as a relevant tool of theorizing but used diagrams extensively, both as a pedagogic tool in his introductory textbook Economics (1948) and as a way of clarifying his theory of public expenditure (1954-5). We show that Samuelson’s reluctance to use diagrams in his early works can be explained by his training at Chicago and Harvard and his rejecting Marshall’s economics, whereas his adoption of visual language in Economics was a product of the peculiar context affecting American mass-education after WWII. A methodological debate which opposed him to Kenneth Boulding in 1948 led him to reconsider the place of visual representation in order to clarify conceptual controversies during subsequent debates on mathematical economics. Therefore, it can be said that the prominent place of visual language in the diffusion of economic ideas was stabilized in the mid-1950s, as mathematical language became the prevailing tool of economic theorizing. From this, we conclude that the idea that algebra simply upstaged geometry in the making of economic analysis must be qualified.

Aleksander Bilimovich (1876–1963) is often considered to have been one of the last representatives of the Kiev School of economics, which was influenced by the German Historical School as well as by the emerging neoclassical theory. After the Soviet revolution, Bilimovich continued his work in exile and was developing his theoretical and methodological views along two lines of the Kiev tradition. On the one side he maintained the historical approach, and on the other side he was inclined towards the deductivist and mathematical approach. The paper thus questions the established view among the historians of Russian economic thought of Bilimovich as a consistent adherent of marginalism. His work bears also several features of historicism.

Frank H. Knight held two different concepts of “uncertainty” in Risk, Uncertainty and Profit (1921). The first is based on the possibility of insuring against an outcome. This interpretation can be found in the existing literature on Knight’s work. The second refers to all instances where individuals have subjective expectations about the future. This second meaning forms the basis of Knight’s (1921) theory of profit and entrepreneurial action (Knight I). Knight I is limited; it provides no explanation of the incentive for entrepreneurial action. Knight’s neglected later theory of profit (1942) (Knight II) highlights the deficiencies of Knight I by offering a clear incentive for entrepreneurial action. The differences between the two theories of profit reflect the impact of incorporating historical time into economic analysis.

In this article, I argue that Adam Smith’s system of perfect liberty contains some of the seeds of perfect competition, but that the modern perfectly competitive model differs from Smith’s perfect liberty in some important respects—in particular, the role of active competition among firms and the role of the entrepreneur. The article examines the analytical linkages between Smith’s system of liberty and three strands of modern economic theory—neoclassical perfect competition, contestable market theory and the Austrian analysis of market process.

The aggregation of budget constraints of enterprises and households allows us to throw a new light on the controversy between Keynes and Harrod concerning the classical theory of the rate of interest. It appears that the critique of the classical theory that Keynes formulated does not presuppose the liquidity preference theory; it is based on the multiplier theory. We show that this critique is logically founded and that it is based upon the absence of the labor market in the analysis of the interdependence between the markets for financial assets and for goods. Harrod did not comprehend it completely. This explains one lacuna in the model of the General Theory that Harrod proposed in 1937. We show that it lacks an equation and that the equilibrium (hence the rate of interest) is indeterminate, which is not the case in the 1937 article by Hicks. We conclude that if there is relevance in Keynes’s criticism of the classical theory, then a similar criticism can be directed at Keynes’s own theory.