We develop a class of discrete, path-independent models to compute prices of American options within the Black-Scholes (1973) framework, including models in which state variables have time-varying volatility functions and models with multiple state variables. Time-varying volatility functions...

Option market activity increases by more than 10% in the four days before quarterly earnings announcements. We show that the direction of this preannouncement trading foreshadows subsequent earnings news. Specifically, we find option traders initiate a greater proportion of long (short)...