Nonlinear estimation techniques play an important role for process monitoring since some states and most of the parameters cannot be directly measured. There are many techniques available for nonlinear state and parameter estimation, i.e., extended Kalman filter (EKF), unscented Kalman filter...

The Samp;P 500 index return interacts negatively with its volatility. This paper traces the negative interaction to three distinct economic channels and proposes to disentangle the relative contribution of each channel using Samp;P 500 index options. First, equity volatility increases...