On the Stability of Intertemporal Equilibria with Rational Expectations

In this Paper we propose a concept of stability for intertemporal equilibria with rational expectations: current period prices move proportionally to current period excess demand while future prices are formed according to the perfect foresight hypothesis. It is shown that this process is locally asymptotically stable if all goods are gross substitutes, or if the equilibrium has no trade. In general this process differs from a t×tonnement in asset and spot market prices. It also differs from Hicks' and exceptional stability. In an intertemporal variant of Scarf's example on the instability of Walrasian t×tonnement process it will be seen that the stability notion we propose is more stable than any other process investigated so far.