Mathematization, Trust, and Belonging in Contemporary Economics

This paper develops a post-neoclassical synthesis between the mathematical formalization of economic theory, represented by Paul A. Samuelson, and the institutional, philosophical, and emotional framework of the Economics of Belonging developed by Carlos Federico Obregón Díaz. The study argues that while formal economic models map the space of possible equilibria, they do not provide criteria for selecting among them. The paper introduces belonging and trust as central organizing concepts that determine how institutions select, stabilize, or transform economic equilibria. It integrates three key contributions: (i) the formal limits of neoclassical capital theory and their resolution through the concept of capital-time; (ii) a reinterpretation of Keynesian macroeconomics as a system of institutional and emotional coordination based on trust; and (iii) an empirical discussion grounded in stylized facts linking growth, inequality, violence, and middle-class expansion. The central thesis is that economic development depends not only on formal efficiency but on the quality of institutional arrangements that generate inclusion, trust, and effective belonging. The paper proposes the Economics of Belonging as a research program for understanding growth, stability, and social cohesion in the 21st century.