Stability of equilibrium asset pricing models: A necessary and sufficient condition

Abstract

We obtain an exact necessary and sufficient condition for the existence and uniqueness of equilibrium asset prices in infinite horizon, discrete-time, arbitrage free environments. Using local spectral radius methods, we connect the condition, and hence the problem of existence and uniqueness of asset prices, with the recent literature on stochastic discount factor decompositions. Our results include a globally convergent method for computing prices whenever they exist. Convergence of this iterative method itself implies both existence and uniqueness of equilibrium asset prices.