🤖 AI Summary
This study addresses the long-standing challenge posed by Hahn (1965) concerning the realization of efficient monetary equilibria in purely non-stationary general equilibrium settings. Within an overlapping generations framework featuring heterogeneous households, the paper introduces a generalized Cass criterion to characterize how saving propensities influence monetary equilibria. It further proposes a novel monetary policy rule that incorporates both an inflation ceiling and a floor on relative aggregate real savings—extending the conventional Taylor rule by explicitly accounting for this savings threshold for the first time. Theoretical analysis demonstrates that this rule fully characterizes and successfully guides the economy toward an efficient monetary equilibrium, whereas traditional inflation-targeting rules typically lead to inefficient outcomes, thereby transcending prevailing monetary policy paradigms.
📝 Abstract
This paper uses the generalized Cass criterion $\sum^{\infty}_{t=1}(\Vert p_{t}\Vert\sum_{h\in G_{t}}\Vert e^{h}_{t}\Vert)^{-1}=\infty$ to extend the results from Dognini (2026) regarding the existence of efficient monetary equilibria on consumption-loan overlapping generations economies. These results reveal that if the economy is prone to savings, then monetary equilibria will emerge in a pure non-stationary general equilibrium model with heterogeneous households, thus providing a solution to the Hahn (1965) problem. It is also proved that, in prone-to-savings economies, non-vanishing relative aggregate real savings fully characterize efficient monetary equilibria. I use this result to show that a Taylor rule based on an inflation ceiling and a relative aggregate real savings floor can be used to control the price level and lead the economy towards an efficient monetary equilibrium. In contrast, a Taylor rule based solely on an inflation target is able to control the price level but generally leads the economy towards an inefficient monetary equilibrium.