Our general aim is to work with models in which zero-coupon bond prices can be expressed in the form
[see paper for equation]
for some n-dimensional, stationary diffusion X(t) and for suitable deterministic functions A(u) and B(u). We prove that the models require a multivariate affine state-variable X(t) as developed previously by Duffie & Kan (1996). The remainder of the paper describes some numerical experiments for specific two and three-factor models which incorporate one stochastic volatility component.
The models have a close relationship with recently developed market models incorporating stochastic volatility. The new models can therefore be used to provide practitioners with a parsimonious benchmark against which more elaborate market models can be compared.
Keywords: term-structure model; multifactor; positive interest; stochastic volatility; time-homogeneous; log-normal; term-structure of volatility.