This paper proposes the Lagrange multiplier test for the null hypothesis thatthe bivariate time series has only a single common stochastic volatility factor and noidiosyncratic volatility factor. The test statistic is derived by representing the model in alinear state-space form under the...

Recent developments in inflation and M3 velocity in the euro area have raised serious doubts about the reliability of M3 growth as a pillar of the ECB's monetary policy strategy. We develop a very flexible and comprehensive state-space framework for modeling the velocity of circulation. Our...

We consider unobserved components time series models where the components are stochastically evolving over time and are subject to stochastic volatility. It enables the disentanglement of dynamic structures in both the mean and the variance of the observed time series. We develop a simulated...