Karl Polanyi's and Karl William Kapp's Substantive Economics: Important Insights from the Kapp—Polanyi Correspondence

Based on the unpublished Kapp-Polanyi correspondence, the paper analyzes the relationship between the two economists, as well as the meaning and origin of substantive economics, i.e. one of the key concepts of institutional economics with distinctly European roots. The correspondence shows how both economists influenced each other in their similar understanding of the substantive economy, and reveals that these similarities and the mutual influence date back to the 'planning debate' of the 1920s and 1930s. The documents also evidence the importance of Carl Menger's definition of substantive economics in the posthumous and untranslated second edition of the Grundsätze der Volkswirtschaftslehre (Principles of Economics) (1923). As a result, Kapp's political economy, i.e. his social minima approach appears in new light. The latter actualizes the full potential of substantive economics for a modern political economy by integrating insights from Polanyi's substantive economics, Menger's differentiation of human needs according to their urgency, and Max Weber's substantive rationality.