In continuous time, diffusion processes have been used for modelling financial dynamics for a long time. For example the Ornstein-Uhlenbeck process (the simplest mean-reverting process)has been used to model non-speculative price processes. The Cox-Ingersoll-Ross process is widely used to model...

Stochastic models with economy-wide shocks imply that the welfare costs of aggregate volatility are negligible and contribute little to explaining the equity premium puzzle. Motivated by this failure, this paper introduces idiosyncratic shocks. Drawing on empirical evidence suggesting that the...