Score-driven models have been applied in some 400 published articles over the last decade. Much of this literature cites the optimality result in Blasques et al. (2015), which, roughly, states that sufficiently small score-driven updates are unique in locally reducing the Kullback-Leibler (KL)...

This paper develops a new class of multivariate models for large-dimensional time-varying covariance matrices, called Cholesky generalized autoregressive score (GAS) models, which are based on the Cholesky decomposition of the covariance matrix and assume that the parameters are score-driven....