We investigate the information theoretic optimality properties of the score function of the predictive likelihood as a device to update parameters in observation driven time-varying parameter models. The results provide a new theoretical justification for the class of generalized autoregressive...

Realized divergence gauges the distinct realized moments associated with time-varying uncertainty and is tradeable with divergence swaps engineered from delta-hedged option portfolios. Consistently with established notions of symmetry in arbitrage-free option markets, implied divergence...

Market data for financial studies typically derives from either historical transactions or contemporaneous surveys of sentiment and perceptions. The research communities analyzing data from these opposing categories of source data see themselves as distinct, with advantages not shared by the...