From the Point to Chaos: The Evolution of the Concept of Equilibrium in Economic Theory

This article reconsiders equilibrium as a representation of economic order. It separates five properties often treated together—existence, uniqueness, stability, convergence, and predictability—and shows that fixed-point results in general equilibrium establish existence without guaranteeing the other four. When uniqueness, stability, convergence, or predictability fails, the relevant object of analysis may shift from a single point to an equilibrium-selection process, a regime, an adjustment path, or a distribution. The same distinction matters empirically because equilibrium is not directly observed but inferred from a maintained model and identification assumptions. We therefore distinguish two ideal-typical orientations: a solution-centred approach, which seeks an object that closes the model, and a temporal-statistical approach, which locates order in persistent patterns of dynamics and distributions. The article argues that the continued appeal of point-based equilibrium reflects its tractability and explanatory simplicity as well as its theoretical role.